Sciencemadness Discussion Board

H2S intoxication

 Pages:  1  

Klute - 10-5-2008 at 03:53

I'm just recovering for an H2S intoxication.... Things are getting better now, but it was scary...

I was performing an Zn/HCl reduction of a Bunte salt (alkylthiosulfate), which evolves H2S along with H2. I will post details of the reduction latter on. Two scrubbers in series were attached to the reaction flask, a 30% NaOH and 10% NaOCl. Theses were very efficent, though at one moment the first NaOH got plugged by what seemed to be sodium (poly)sulfides, so the bleach washbottle was attached first. It turned yellow over a few minutes and sulfur particules appeared, it didn't change appearance before, so the NaOh seemed to handle the H2S pretty well. I wore a gas mask at all times, one that is efficient at protecting from things like SO2, HCl, organic vapors. The cartdriges weren't new though. When I had to refill the addition funnel, i got a slight smell in the gas mask, so I went to take some fresh air, and did so regularily after. I was working in a garage with the large door (the one to let the car in) wide open, and a normal door on the opposite side wide open too. It was very windy.

The reaction finished, it was letf to stir over night. A current of argon was passed for a few minutes, expecting it to chase away remaing H2S. The grey sludge was transfered to a seperating funnel, and extracted 3 times. The smell was pretty strong when I took the gas mask off, so I spent as little time as possible in there, just the time to seperate layers and add more solvent.

Then i started to get dizzy. I realized i didn't sense the smell in the gas mask at all, though a relative passing by was disgusted by it. My hands started to shake, my heart beat raced, and I felt wxeak. I closed the sperating funnel immediatly, and went outside. The symptoms weren't going away. I advised my relative I wasn't feeling well, and that if things didn't get better soon, they would have to take me to the hospital. I had a bad taste in my mouth, and dry saliva.
I checked the dosage for sodium nitrite, which I had on hand, and finally decied on injecting 50mg in 1mL. I was lucky enough to manadged to inject myself with my hands shaking. My heartbeat suddenly increased as the nitrite came up. The arm was a bit painfull at first, i had stings and needles for 5min, but them the symptoms gradually decreased. My hands stopped sahking, and I am generally feeling better now. I am waiting to see how things evolves, and am considering seeing the doctor or hospital, been concerned about delayed pulmonary oedema. I will have to got and clean up the lab at a moment, but prefer waiting until most of the smell is gone. I will neutralise the sludge with Ca(OCl) or large amount of NaOH, taking in acount that over 350mL conc HCL is present.

Any advice on neutralisation is welcome, aswell as any experience with this kind of poisoning, particularily the delayed effects.

I would recommend anyone willing to handle H2S out of a proffessional environment to SERIOUSLY reconsider. I was very lucky this time. If i had stayed a few minutes more, I could have fell unconscious, at which point I would have put my life and the one of my relatives at serious risk.

I don't understand how the authors of the publications I have read proceeded to do the workup, even in a fume hood, without being exposed to the gas.

[Edited on 10-5-2008 by Klute]

ScienceGeek - 10-5-2008 at 05:24

Wow, Klute, that is quite an experience you've had! And your writeup of your experience is very good!

If something like that were to happen to me, I definately think I would go to see the doctor! Pulmonary Oedema might not be evident after as long as two weeks!

For now, take care :)

EDIT:
PS: I surely hope it won't come to this, but if it should:
When you inject the NaNO2, do you inject it sub- cutaneously, intramuscularly, or intravenously?

[Edited on 10-5-2008 by ScienceGeek]

Klute - 10-5-2008 at 06:06

IV injection. I would definatively advise to get proper medical dosage, I did this out of panic, sodium nitrite is a poison itself. Boy did i feel weird opening a reaent bottle and preparing a shot with it...
The correct dosage are:

Sodium Nitrite (3 % IV solution):
Adult: 10 ml at 2.5 to 5 ml/minute, or 0.35 ml/kg IV push
Child: 0.2 ml/kg not to exceed 10 ml.
source

Not having a catheter, and not wanting to put one anyway, i did a push injection (all in 1 go), but only 50mg instead of a 63mg (i weigh just under 60kg), not wanting to making a too concentrated solution. It was painfull.

I really do not advise anyone to do what i did, only if there are no other options. I'm not a doctor, and have virtually no knowledge in the area. Nitrite treatment can be hazardous itself. And injecting yourself in such a situation is very delicate. In good conditions, someone who never injected himself will have difficulties, so doing so when your hands are shaking and your are in panic, would be near impossible. I (un)fortunaly have experience with injection so managed to do so correctly and quickly.

For the moment, i feel that i have completly recovered. Just a salty taste in the mouth from the injection. I will see a doctor and tell him what happened, i know both H2S and NaNO2 can cause some disorder in blood equilibrium and such. For the moment i have no problems at all with breathing, so I'm crossing my fingers.

I have clean most of the glassware and neutralized the solution with Ca(OCl)2 conc solution. I was surprised at the amount of sulfur it deposited, meaning there was a pretty large amount of dissolved H2S...

I will go back at using S2Cl2 for futur sulfide synthesis now, it nearly seems like a harmless compound compared to H2S!

Once again, i was very lucky. I have to insist on warning anyone out there considering a reaction involving/generating H2S. The thrill is nothing compared to your life. I don't give a fuck of the end product now, even though I've kept the extractions and washed them with brine to remove most of the dissolved H2S. I will never risk my life for a reaction again, and never under estimate the toxicity of a compound, or over estimate the safety conditions I work in at home.

ScienceGeek - 10-5-2008 at 06:26

Thank you for the details on injection! I hope I'll never have to use any of the information you gave me!

Regarding your experience with dangerous procedures, I'm glad to hear that you won't do it again! To me it seems that you took all the necessary precautions possible for a home chemist (maybe a fume- hood would have done a better job in removing the H2S), but still!

Good luck in the future involving dangerous procedures! I hope this experience haven't put you completely off syntheses involving some degree of risk! :)

stateofhack - 10-5-2008 at 06:45

Woa that is pretty impressive :o sad to hear about this :(

I hope you fully recover well!

woelen - 10-5-2008 at 07:36

IIRC H2S does not cause pulmonary edema, but nevertheless, it is good to see a doctor. You have had good luck that you realized just in time how dangerous the situation was. I, however, in your situation probably would have gone outside and lay down in the grass or something like that, far away from the H2S, in fresh air.

Fortunately I never encountered really dangerous situations in my home chemistry experiments, I usually work with very small quantities.

garage chemist - 10-5-2008 at 07:47

Instead of the difficult and hazardous IV injection if sodium nitrite, would inhaling some butyl or amyl nitrite have the same effect?
Amyl nitrite is recommended as a first-aid antidote against HCN in my OC book, along with intravenous NaNO2 later by the doctor.

So would making a small amount of an alkyl nitrite before working with H2S or HCN be as good or better (because of the ease of inhaling it versus having to do an injection of NaNO2) than keeping a shot of NaNO2 ready?

stoichiometric_steve - 10-5-2008 at 08:01

why dont you all just use a fume hood...even if you have to invest some time, money and work, what is this compared to your life?

Klute - 10-5-2008 at 08:19

I definitevely want to build a fume hood. I just thought i could manadge this reaction without it, but that was underestimating H2S.

Taking fresh air is the first thing I did, the time i got less dizzy and considered the situtation. A certain number of MSDS i have consulted claim H2S exposure causes delayed (from a few hours to days) pulmonary edema. I have contacted my local anti-poisoning cneter, explaining them what happened, they said as far as all symptoms are gone there sin't anything to worry about anymore. They did advise me to see a doctor if i feel some disconfort while breathing. They obviously told me to consult a doctor immediatly when this happens, and to never inject any antidote by myself again, even if it is a known one.

Amyl nitrite is said to work waiting for a NaNO2 injection, but can't suffice alone, at least from what I've read. But i guess it's the best thing to do while waiting for proper treatment. The quicker after the exposure, the better.


I'm very glad I got out of there as soon as I felt something was wrong, but feel very stupid of even getting to that point. I am seriously reconsidering improving the security conditions before doing any other reaction, in case of un-planned events.
Indeed, a few hundred euros a few weekend's work are nothing compared to life, or even health. And that smell.. brr...

blogfast25 - 10-5-2008 at 08:26

Well, this is the first forum-declared case of H2S poisoning that I've ever come across. Scary... especially as I've been around the gas quite a few times. Al/S or Al/CaSO4 boosted thermites of SiO2, TiO2 (and potentially others) that I routinely use, all produce rapidly hydrolyzing sulfides like Al2S3 and CaS and the smell of rotten eggs coming off the slag (even when freshly fused, thus 100 % dry) is often intolerable. I dispose of them usually by soaking in bleach, prior to binning.

It's to avoid the terrible smell I developed S-free booster packages, based on KClO3 or nitrates. But I still occasionally use CaSO4/Al (--->CaS + Al2O3) because it's so powerful as well as cheap as chips.

It kind of begs the question: what's the concentration of H2S at dangerous levels and how to pre-emptively detect it?

And it makes you wonder how many cases of this kind of poisoning must have occurred when the Leblanc process for the production of soda was still in use: it produced hundreds of thousands of tons of CaS watery slurry (the so-called galligu)... :mad:
Quote:
Originally posted by stoichiometric_steve
why dont you all just use a fume hood...even if you have to invest some time, money and work, what is this compared to your life?


If concentrations reach danger levels, spewing the stuff into open air in a residential area is hardly considerate... Some kind of scrubbing/incineration would be advisable.

garage chemist - 10-5-2008 at 08:32

One could just feed the exit of the apparatus into the air intake of a bunsen burner, this will efficiently take care of the H2S without the need for additional chemicals.
Also install some backdraft protection, like stuffing a piece of steel wool into the pipe, to avoid igniting a H2S/air mix inside the apparatus.

panziandi - 10-5-2008 at 08:57

But then wouldn't you have sulphur dioxide to contend with? Which I find quite unpleasant. :(

woelen - 10-5-2008 at 09:07

SO2 is not nearly as toxic as H2S. SO2 is tolerable up to 10 ppm or so, H2S is very dangerous already at 1 ppm. The only trouble with SO2 is that it can induce astmhatic attacks in allergic people, but normally it is not that toxic.

BromicAcid - 10-5-2008 at 09:10

Garage chemist, if you lead it into a Bunsen burner though you're going to get acrid sulfur dioxide instead, safer but still a pain in the butt.



That's a picture of my wash bottle from reacting carbon with sulfur. It made plenty of H<sub>2</sub>S. At first it was just NaOH (aq) in there to absorb any incidental generation (didn't think there would be much) but my grandmother came out and told me she smelled rotten eggs. I couldn't smell a thing, so, panicking somewhat I dumped some aqueous copper sulfate into the solution to see to what degree it was saturated (I expected most of it to just turn into blue precipitate) and instead of what I expected it turned into a fine black powder seen in the picture. Anyway in retrospect I may have been experiencing some tremors or weakness but not to the extent you mentioned. Still, it was surprising that it killed my sense of smell, I might have caught a hint of it, that was it.

Klute - 10-5-2008 at 09:49

NaOH solution seems very effective at handling H2S, but you need to plan on using alot of it. As mentionne dearlier, at one moment, the tube going down in the solution got clogged up with some white solid, surely sodium sulfides. I'm not sure if it's better to use a >30% solution of NaOh, for maximum absorption, or a more dilute one that will dissolve more sulfides.
The bleach scrubber was pretty efeective too, it turned yellow after a while with fine solids in suspension. No clogging up at all.
Both were pretty hot (>40°C) from the large flow of H2S generated.

the best way of getting rid of it in a fume hood would be to avoid release some as much as possible, using washbottle and such, and maybe use a solid Ca(OCl)2 "screen" in the evacuation tube.
I think H2S get's oxidized pretty quickly in the atmospher anyway, the smell didn't stay long once all the solution/glassware were neutralized.

MagicJigPipe - 10-5-2008 at 10:57

In response to some of the NaNO2 injection and akyl nitrite inhalation questions I have done much research on the subject. The alkyl nitrite inhalation may save you if you inhaled a small amount. It's to keep you from passing out (or dying) before the more involved injection can be done. It wears off within a few minutes so the subsequent injection is almost always done.

If you plan on making up an injection kit use USP (or whichever Pharmacopia grade you have in your country) NaNO2. That's what is used in the professional antidote kits. If you prepare the solution before hand adding .075% (by weight) sodium benzoate and 1% w/w citric acid will make the solution bacteriostatic (a must for anything entering your body, especially IV). ALWAYS use sterile water (if you don't have access to this at a hospital you can order it online or sometimes use eyedrop solutions THAT CONTAIN ONLY SODIUM CHLORIDE can be used if it says it is sterile). MEASURE OUT THE NaNO2 CORRECTLY. USE LESS RATHER THAN MORE (50mg). Also, this is for other drugs and not specifically NaNO2. Also, make sure the pH is neutral! Benzyl alcohol can also be used in place of sodium benzoate but it can be harmful. Apparently they had to take it out of infant medicine because it was causing deaths. It's still used, though. Actually, it's probably more common than benzoate. DO YOUR OWN RESEARCH. THESE ARE JUST SUGGESTIONS.

EDIT
After some research I now recommend BnOH. If you need BnOH USP (it will be repacked under non-USP conditions but it will be clean) I have it. I also have sterile water.
Quote:
Bacteriostatic Water for Injection, USP is a sterile, nonpyrogenic preparation of water for injection containing 0.9% (9 mg/mL) of benzyl alcohol added as a bacteriostatic preservative. It is supplied in a multiple-dose container from which repeated withdrawals may be made to dilute or dissolve drugs for injection. The pH is 5.7 (4.5 to 7.0).
From: http://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?id=1...

I would do this even if you don't need to make multiple extractions simply because the environment inside the home is not "clean". Also, NaOH and HCl are used to adjust the pH of parenteral solution. DO NOT USE A POTASSIUM BASE.

Like Klute pointed out doing an IV injection without experience, ESPECIALLY ON YOURSELF, is damn near impossible so, if you are really concerned with poisoning, learn how to do it very well or teach someone else that will be in the area how to do it. I mentioned this and was told that my girlfriend would leave me if I told her that ;) Actually, I did tell her about it and she said it was good that I was taking every possible precaution (even with a fume hood and SCBA gear, accidents happen).

I used to sell hypodermic needles (legally and not to "junkies", I hope) so if you live in a state (I don't think I want to ship something like that overseas where it might be illegal) that won't sell them without a prescription (or if you don't want to be seen buying them) I will send you some. I would actually ask you to reconsider the experiment first but if you're set on doing it, I'd rather help you out with the supplies than not.

P.S. Check your state laws. In most states, simple possession is not a crime even if they require a prescription to buy. Drug paraphenilia can (usually, I'm not sure now with the state of this fucked country) only be claimed if you have drugs. Just don't carry them in your car! Duh! I have to do it but they are all in the packages and I have no drugs so... Also, IV injections are not as finicky and unforgiving as everyone believes. BE CAREFUL, but also don't believe all the hype.

Anyway, I'm rambling now. Just everyone be safe and take every precaution. If you don't feel comfortable having to do something like this, don't do the experiment. This can be dangerous. Do your OWN research and do not rely soley on mine. You should always do that, by the way.

Also, I was unaware, until now, that nitrites were an effective H2S antidote. Interesting.

EDIT
You should let the hospital or doctor do the injection. However, if you think you can do it properly, the sooner the better. The poisoning is WAY more likely to kill you than the injection (it's pretty unlikely, really). I would actually be scared to go to the doctor. Can you imagine the questions? I mean, I called the poison control center once to ask about iodine poisoning. They WOULD NOT give me any information without taking my full name, phone number and address down. Naturally, I declined (and called from a payphone). They kept asking, "How did you get exposed to iodine? What were you doing? Where was the iodine located? (asking for an address). I called a few weeks later (out of curiosity) about mercury and they asked no such questions. God I hate the meth scare. Now you can't even get medical assistance anonymously if you are messing with chemicals that could be meth precursors (I know H2S is one on some list somewhere, along with almost every other common chemical).

[Edited on 5-10-2008 by MagicJigPipe]

Klute - 10-5-2008 at 13:46

In my country it's totally legal to posses injection equipment. Sterile equipment is distributed freeely by harm-reduction associations, one of which I am a member.
Although sterile water and filtering was sued, the sodium nitrite was far from USP, being a technical grade. I wasn't going to do a fuss about that at the time. Considering it's 90% minimum, that's 5mg impurities maximum, mostly sodium nitrate, so I'm not too concerned.

You are right to point out that no potassium salts should be used IV. This can cause immeadiate heart failure.

Again, i wanted to share my (bad) experience, but do not advise doing this in case of hydrogene sulfide poisoining, unless there absolutly no other solution. Only a trained medical personal can decide on nitrite treatment, and taking charge correctly of such an intoxication.

len1 - 10-5-2008 at 14:32

Thanks for posting that Klute, the safety measures you have - gas mask, breeze throgh work place, frequent trips outside, conc. NaOH scrubber (I never bother with 2) sound very similar to mine, which I thought effective. So this could have happened to me, and serves as a good warning.

The one difference I have is a fume hood, but its not all its cracked up to be - you still have to open it to wash precipitates, dismantle apparatus, and especially in the cleanup, thats when you get exposed. Even if you do all that in there, the protection is then only 50% effective.

Gas masks we use are not war gas masks, if you wore them during a phosgene attack, you'd die. Thats because the switch mechanism from in- to exhale is a trivial diaphragm, you still get up to 10% of your gas from outside. So thet offer protection up to 10x allowable exposure - bot no more.

It is possible, though not a relief, that the hands were shaking from anxiety once the diziness set in and you realised what happened - thats just some observations ive done on myself

Klute - 10-5-2008 at 15:19

Yes Len, I was pretty surprised myself considering the conditions, and the only rare times I actually smelled the gas. The hands shaking was actually what made me realize this wasn't just dizzyness from keep me breath when opening the apparatus, as I sometimes have. It was pretty spooky, because uncontrolable. I manadge to calm myself pretty well just before injecting the antidote by deep breath and emptying my mind.

I have just finished removing the solvant: the recovered product is neglieable, i guess toluene isn't a good solvant. I risked my life for nothing :D Better laugh than cry about it...
So back to S2Cl2 when the fume hood is up then! :)

len1 - 10-5-2008 at 16:03

I also use the hold-your breath trick at tricky moments, even in a gas mask.

Still Im trying to understand the source of the problem, because I havent completely given up on H2S work, and I consider this work as a mandatory prelude to any work with cyanides.

I am also in a much less enviable position then you. This sort of hobby is very borderline here, much less understood than in europe - I can not afford any serious mistake, one ambulance or fire-brigade call, and thats it. And it'll just reinforce the prejudices of the masses regarding our hobby.

So it would be of help to know the scale of your work - how many moles of H2S got generated?

Also, the error I understand was the clogging of the tube and the momentary disconnect of the traps. Or was most H2S released during work-up?

As I understand a fume hood or a 'professional environment' will really not solve anything - the same thing can happen there. My lab hasnt a hint of smell in it while the reactions are going on in the fume hood. Its beautiful and you can enjoy yourself. But it all changes when the hood opens during workup or cleanup.

Presently I think the essence is this:

the key advantage of H2S, our ability to detect it in tiny concentrations, is a faux ami, it lulls you into a false sense of security. A reliable H2S detector needs to be found and several located in the lab. If thats triggered, a response (other than just fleeing the lab) should be prepared.

[Edited on 11-5-2008 by len1]

Saerynide - 10-5-2008 at 16:04

Wow, that is really something. I'm really glad you are ok. I got Cl2 poisoning 5 years ago and it was not fun. Took me a month to get better (meaning I could stop worrying that I'd just die in the middle of the night), and about a year to feel completely ok again :(

stoichiometric_steve - 11-5-2008 at 00:54

Quote:
Originally posted by BromicAcid it was surprising that it killed my sense of smell


H2S can only be detected in LOW concentration by the human olfactory sense.

The rule is: If you know you SHOULD be smelling it and you DON'T -> GET THE FUCK OUT!!!

blogfast25 - 11-5-2008 at 05:38

Quote:
Originally posted by len1

So it would be of help to know the scale of your work - how many moles of H2S got generated?



That seems to be the crucial question to me here. Many of use will come into contact with H2S during various experiments, it's a frequent by-product of sulphur chemistry but few will suffer adverse effects like Klute...

For that reason it would be interesting if Klute could estimate, even roughly, how many moles of hydrogen sulphide were generated during the course of that job. Generating H2S as an unwanted by-product is one thing, using it as a reagent quite another and would, IMHO, require different types of precautions...

Klute - 11-5-2008 at 05:45

The reaction itself liberated 0.2mol of H2S, most of which were completly neutralized by the scrubbers. The
2 times I had to open the setup (recharging the addition funnel with conc. HCl and swapping the scrubbers, I just got the bad smell and nothing more, no disconfort at all.
The intoxication was noticed at the third extraction of sludge, contained in a large seperatory funnel, always leaving the place between washes and letting time to settle, so i wasn't in there for more than 2-3min at the time. The beaker used to contain the sludge when sperating the toluene was left in the air, which was probaly a mistake, as it offered a good surface for desorbtion. The flask was immeidatly washed with dilute hypochlorite after transfering the sludge out, so I guess the gas came from the seperating funnel, and much more when emptying it in the beaker.
I'm sure an efficent hood would have minimized exposure, but you would need a vey high flow and the sash way down, as the gas is heavier than air... Although it was very windy in the garage (can't leave a piece of paper not pressed down by an object, even a empty PP mesuring funnel had to be placed on the floor as it kept on falling), the geometry, and the furniture must have prevented a efficient evacuation.

The form of the garage is basically like this:
with a shelf in the middle, and the two doors on the sides. The wind was comming from the small door (on the right)

________bench______
|............||||||||||||........|
<...........||.....................|
<...........||.....................|
<................................<<<<
|__________________|



Funny you mention not sleeping at night, this happened to me, I felt that if I would go to sleep I would stop breathing, and I had arythmy (Sp?) when your heartbeat suddenly slos down then speeds off in a irregular way. I only had a few hours sleep. Now things are better, so I guess there was a part of anxiety. If this happens again tonight, I will talk to the doctor.

Actually, if I didn't call the medics when not feeling well, it was mainly for the same reasons as Len. Plus, i didn't want to leave a potential source of H2S unattended with relatives around, or with a medical team comming: they would have sent HAZMAT team (or the equivalent here). Legally, i don't think it's a problem having a small lab, but the insurrance wouldn't be happy of learning there are solvants and chemical stocked in the garage, albeit in small quantities. And the cops would surely think explosives or drugs and make a full investigation. i don't want to take the risk of falling on a cop that considers that if I have iodine and HCl, I'm surely making meth, if I've got diethylamine and methanol, I'm surely making LSD, nd if I've got H2O2 and acetone I was surely planning on high-jacking a plane so they might just aswell put death penalty back up...
Bref...

I'm starting my plans for the fume hood now, and I actually kept the syringe that possibly saved my life :) I don't think I'll show it to my granchildren if I have some though :D

[Edited on 11-5-2008 by Klute]

MagicJigPipe - 11-5-2008 at 08:15

Arythmia is irregular heartbeat. The slowing down of the heart below 60bpm (which isn't always bad, I've often had heatrates below 60bpm while I was in shape) is called bradycardia. Tachycardia is the opposite (above 100bpm, this is at rest and not while you are "applying yourself" physically).

All can be extremely dangerous if they are caused by a substance. Especially arythmia which can lead to a very bad type of arythmia called ventricular fibrilation (V-fib) which is basically when the electric signals that keep the heart in rythym get screwy and cause the heart to "tremble" rapidly instead of beat regularly.

V-fib is scarey shit. Seems like a horrible way to go. I even hate talking about it. So I'll stop.

[Edited on 5-11-2008 by MagicJigPipe]

kmno4 - 11-5-2008 at 11:38

I work in a factory, where is H2S in industrially produced and I saw only one case of H2S poisoning. It was caused by leaking sluice valve and man standing close to it took a deep breath.
He made few steps (propably he wanted to run) and fell down, loosing consciousness.
Fortunately, after ~10 seconds he awoke, got up... and it is all story. The most scaring thing for me were his eyes opened during
those 10 seconds ( I was holding his head and screaming his name, heh). People are afraid of HCN, but often forget that H2S has the same "power".

LSD25 - 11-5-2008 at 12:45

This is a fairly good description of what H2S does and does not do (be aware, this details brain damage in a Rhesus monkey resulting from non-lethal exposure, which is kinda scary: the article - http://www.euro.who.int/document/aiq/6_6hydrogensulfide.pdf):
Quote:
Effects on humans
In its acute form, hydrogen sulfide intoxication is mainly the result of action on the nervous system. At concentrations of 15 mg/m3 and above, hydrogen sulfide causes conjunctival irritation, because sulfide and hydrogen sulfide anions are strong bases (11). Hydrogen sulfide affects the sensory nerves in the conjunctivae, so that pain is diminished rapidly and the tissue damage is greater (11). Serious eye damage is caused by a concentration of 70 mg/m3. At higher concentrations (above 225 mg/m3, or 150 ppm), hydrogen sulfide has a
paralysing effect on the olfactory perception (2), so that the odour can no longer be recognized as a warning signal. At higher concentrations, respiratory irritation is the predominant symptom, and at a concentration of around 400 mg/m3 there is a risk of pulmonary oedema. At even higher concentrations there is strong stimulation of the central nervous system (CNS) (2), with hyperpnoea leading to apnoea, convulsions, unconsciousness, and death. At concentrations of over 1400 mg/m3 there is immediate collapse. In fatal human intoxication cases, brain oedema, degeneration and necrosis of the cerebral cortex and the basal ganglia have been observed (11).

If respiration can be maintained, the prognosis in a case of acute hydrogen sulfide intoxication, even a severe one, is fairly good. There are reports of neurasthenic symptoms after severe acute intoxication, such as amnesia, fatigue, dizziness, headache, irritability, and lack of initiative (11). A decrease of delta-aminolaevulinic acid dehydrase (ALAD) synthase and haem synthase activity in reticulocytes one week after hydrogen sulfide intoxication has been reported (12), together with low levels of erythrocyte protoporphyrin. The ALAD and haem synthase activities returned to normal two months after the accident, erythrocyte protoporphyrin remaining low. Changes in the electrocardiogram have been reported after acute hydrogen sulfide intoxication, these changes being reversible (11). No tolerance to the acute effects of hydrogen sulfide has been reported to develop (11). The mortality in acute hydrogen sulfide intoxications seems to be lower than that reported in 1977; according to a recent Canadian report it is now 2.8% (13), whereas formerly it was 6% (2). This may be a result of improved first-aid procedures and increased awareness of the dangers of hydrogen sulfide.

Information about longer-term exposures to hydrogen sulfide is scanty. Eighty-one Finnish pulp mill workers who were exposed to hydrogen sulfide concentrations of less than 30 mg/m3 (20 ppm) and to methyl mercaptan concentrations of less than 29.6 mg/m3 (15 ppm), displayed loss of concentration capacity and chronic or recurrent headache more often than a nonexposed control group of 81 workers. Restlessness and lack of vigour also appeared more often, but the findings were not statistically significant. There was also a tendency towards more frequent sick leave among the exposed group (6). One report cites decreased activity of haem synthesizing enzymes in reticulocytes of pulp mill workers exposed for years to organic and inorganic sulfides, with hydrogen sulfide concentrations of between 0.075 mg/m3 and 7.8 mg/m3 (12). No information is available as to whether the observed effect was related to peak concentrations or average concentrations. It can, however, be assumed that average exposure was considerably higher than 0.075 mg/m3 (around 1.5-3 mg/m3). Furthermore, there is no firm proof that hydrogen sulfide was the causative agent, as there may be confounding factors (other substances).

Epidemiological data concerning longer-term exposures are limited. Seventy per cent of workers exposed to hydrogen sulfide daily, often at 30 mg/m3 or more, complained of such symptoms as fatigue, somnolence, headache, irritability, poor memory, anxiety, dizziness, and eye irritation (14). In a Finnish mortality study workers in a sulfate pulp mill showed excess mortality from cardiovascular diseases (standardized mortality rate 140), and especially from heart infarction (standardized mortality rate 142). The findings were statistically significant. In the same study population, cancer incidence was not significantly different from, that of the general Finnish population (15).


Brain oedema and increased risk of heart/lung condition(s) appear to be the more disturbing long-term effects, while pulmonary oedema in the short-medium term would suggest that a visit to the doctor is mandatory. The good news is the lack of increase in risk of cancer(s) (which is associated with both phosgene and mustards).

What about a strong ammonia solution as the scrubber?

Klute - 11-5-2008 at 14:17

I think there was a certain numbing effect, as today I have a slight chest pain and irrated sinus, that i didn't feel yesterday.
Also, the symptoms during lest night seem to correspond pretty well to Paroxysmal nocturnal dyspnea, so I am definatively going to see a doctor tomorow, even though apparently nothing much can be done to cure it. I will try to use a extra pillow or two and see if it helps or not..

Well keep you guys updated with the doctor's advise.... Hope I will be able to get some sleep tonight.

pantone159 - 11-5-2008 at 22:00

Quote:
Originally posted by Klute
Also, the symptoms during lest night seem to correspond pretty well to Paroxysmal nocturnal dyspnea


This sounds similar to 'Cheyne-Stokes' breathing which affects people at high altitude. Sometimes people wake up with a feeling of suffocation.

According to 'Medicine for Mountaineering', 4th ed, Wilkerson ed:
Quote:

Acetazolamide (159- I think this is 'Diamox' http://en.wikipedia.org/wiki/Acetazolamide ) relieves the periodic breathing seen at altitude. Sedatives are harmful in such situations and should be avoided. An aminophylline rectal suppository at bedtime may help if respiratory irregularity prevents adequate rest.


I wonder if Diamox would help? (Does sound better than the last bit.) Hope you are ok..

MagicJigPipe - 12-5-2008 at 00:36

Ooooohh... Yeah, those suppositories are always so much fun! :( I have gone to sleep before after taking 50-75mg of diphenhydramine HCl and have woken up because I stopped breathing. It's a terrible sensation to wake up and feel like you've been underwater for a few minutes and then have to catch your breath. I would have to say definitely avoid depressants. Especially alcohol and opiates!

Klute - 12-5-2008 at 05:50

I have a medical treatment that must worsen things. This night wasn't as bad as last night, but i still woke up several times with the impression my heart had stop beating and I was not far from passing out. Sitting upright and walkign a bit made things better, I used sevral pillows and slept with a 45° angle, which must had improved things as I didn't wake afterwards.
No coughing up though, and the chest pains have disappeared, so I guess things are improving. I completly forgot this is a non-working day in France, so my doctor isn't working, I will wait for tomorow to go there.

Saerynide - 12-5-2008 at 12:13

Yeah, that was the absolute worst part for me. I couldn't sleep for weeks because I kept waking up and finding that I stopped breathing :( Sleeping with a whole bunch of pillows so that you're almost sitting up helps.

MagicJigPipe - 12-5-2008 at 12:28

Klute, do you mean your heat skips a beat? Mine does that every now and then and it always scares the shit out of me. Just 2 days ago I was eating at a restuarant and my heart stopping beating for what felt like a 3 seconds or so. I almost passed out just from being so startled.

My heart skips a beat maybe twice a week. Does anyone else get that sensation that often?

Klute - 12-5-2008 at 12:47

Funny you mention that, I used to have that problem a while back, at one point i couldn't go to sleep correctly because of it and suffered from pretty severe sleep deprivation... it haunted me.. and i was so scared of it happening again i would look out for it and never be able to peacefully dozz off...

It stops roughly at the same time i stopped smoking (i was smoking nearly 2 packs a day, and maanged to stop one day and never started since), and haven't been bothered with it since, so i simply considered it to come from smoking.

What i felt these two last nights was similar, but much more alarming, it "felt" more dangerous. I'll tell the doctor of the previous beat disorders, maybe it could be connected, like having an undergoing problem that has been re-awaken by the exposition.
Smoking possibly worsened things in the past, and when i stopped things went better to the point were it didn't disturb me anymore, the gas possibly did the same thing that cigaret smoke did but in a much shorten period.

LSD25 - 13-5-2008 at 02:56

Quote:
Originally posted by MagicJigPipe
Ooooohh... Yeah, those suppositories are always so much fun! :(


Don't like it? Shove it up your arse:D

MagicJigPipe - 13-5-2008 at 08:53

That has to be it. I smoke a little less than a pack a day (lights, every 24hrs) and have been smoking for about 3 years. At one point I got up to two packs a day (full flavor) while I was delivering pizzas (I chain smoke while driving). I'm actually taking it slow and smoking 1 less cigarette per week. I started out at 20 a few weeks ago (1 pack) and now I'm at 17.

I could have sworn I got this sensation before I started smoking, though. It just didn't scare me as much until a bad episode I had with a certain drug about 3.5 years ago.

I think you're right about the cigarette smoke doing basically the same thing over a longer period of time. And certainly cigarette smoke contains some H2S.

AngelEyes - 14-5-2008 at 05:01

This maybe slightly OT, or possibly even getting us back on topic, depending on how you look at it.

Rats. I have them living under a shed in my garden but because the little b*stards only come out at night it's tricky to take the air rifle to them. And because the shed was build on concrete and sand it's not exactly practical to lift or move it, yet they're under there as I can see gnawed holes in the sides and stuff.

Anyway..I was thinking about an easy way to get rid of them and I thought 'gas them'. OK...so which gas? It would have to be toxic, easy and cheap to produce and heavier than air so that it would sink into the foundations and rat holes. So my first thought was Chorine. But then I thought 'nope, that's a WW1 chemical weapon...plus the fact that it makes strong acids when exposed to water which are not the kind of thing you want eating away at your foundations'. Then I considered CO<sub>2</sub> (probably not toxic enough), NH<sub>3</sub> (lighter than air and would float away), SO<sub>2</sub> (produces strong acids with water)...none of them were suitable for reasons provided. So then I thought H<sub>2</sub>S - easy to make, toxic and heavier than air.

What do you think? Make some FeS and pop it in a bowl or container of some kind. Place this container(s) into one (or more) of the hole as far in / down as I can, and then pour some dilute acid onto it. Place a bit of wood over the hole for added cover and then leave the gas to sink down into the rat den. Because of the stink, any other animals (like cats) should leave it well alone and the rats should all die. Or they run out and I'm waiting with my air rifle.

Appreciate any comments

Thanks


Angel

Klute - 14-5-2008 at 10:04

Why not use rat poison? It effective, selective, and it's not going to kill you unless you eat it (in which case...).

H2S isn't controlable, and will kill much more than rats. Imagine your little sister comming to play around while you realize the wind just died down and you smell rotten eggs.. ARe you going to inject here some sodium nitrite? Plus it reacts with water leaving toxic/basic sulfides. Just avoid the stuff IMHO.

I did a reaction with it because the target compound can't easily be obtained by other means. I would not do a reaction with it if i had other means to do so, and I will certainly not use it to kill rats while a whole bunch of stuff can kill them. Damn even alkali cyanides would be safer IMHO.

[Edited on 14-5-2008 by Klute]

MagicJigPipe - 14-5-2008 at 10:27

I tried to get a racoon out from underneath my house (crawlspace, I have a wooden foundation suspended above the ground) at one point by "gassing" it with a small bucket of heated, household ammonia. For some reason it does not seem to affect animals the same way. It was pretty uncomfortable to stay in there.

By the way, joedick, thanks for cluttering up and hijacking the thread with your random comments. Try using the edit feature next time. Triple posting is frowned upon.

[Edited on 5-14-2008 by MagicJigPipe]

joeflsts - 14-5-2008 at 13:23

Quote:
Originally posted by MagicJigPipe
I tried to get a racoon out from underneath my house (crawlspace, I have a wooden foundation suspended above the ground) at one point by "gassing" it with NH3. For some reason it does not seem to affect animals the same way. Even though just walking within a few feet of the entrance caused me to recoil in horror while my nose and eyes leaked like crazy, the damn thing didn't come running out. Eventually it got so concentrated that I thought I was going to kill it (or get the police called on me. To the average person in my area any chemical smell means METH).

I thought for sure that the horrible sensation would cause the damn thing to run out as quickly as possible. My guess is that it's natural reaction is to run away from what appears to be the source of the chemical so it might have just huddled in a corner, scared shitless. Maybe it thought it would only get worse if it went towards the door... I don't know...


And we wonder why chemistry as a hobby is frowned upon.

Joe

joeflsts - 14-5-2008 at 15:15

Quote:
Originally posted by MagicJigPipe
What are you, one of those crazy PETA people? What's the difference between what I did and what AngleEyes is trying to do except for not trying to kill the animal? You may like rats, racoons and other annoying animals inhabiting your dwelling but I don't. What does it matter how I get rid of it? Would you rather I shot and killed it? Oh, yeah, that would have been better, just kill it, right?

All you ever do on this forum is talk about legal issues and shit. Where's all your interest in chemistry that makes you so worried? I can't believe you would have the nerve to come to this thread and say some bullshit like that out of nowhere. Why don't you try contributing to some chemistry discussions for a change?

Stop talking out of your ass like you always do and FOD.

[Edited on 5-14-2008 by MagicJigPipe]


I think you should takes Klute's advice. I could care less what you think about me.

Joe

joeflsts - 14-5-2008 at 15:29

Quote:
Originally posted by MagicJigPipe
Klute didn't give me any advice. Nor did he give any advice to anyone that has anything to do with me. That being said, what the hell are you talking about?

Once again, talking out of your ass.

If you delete your posts I will delete mine. Next time you should keep your presumptive and instigative comments to yourself.


I see no reason to delete my posts.

Joe

Ozone - 14-5-2008 at 16:24

Well, there goes another interesting thread...

But, before then, I am glad to hear your OK, Klute. The skipped heartbeats are likely premature ventricular contractions (PVCs, jokes aside). The electrical signals in the heart become borked and the heart "resets". The result is a skipped beat followed by a really hard one (almost a s freaky as the skipped beat).

I quit smoking (after 19 yr) one year ago and they have decreased, but not gone away. I was "clocked" (with a Holter monitor) at 1300+ PVCs/d!

Anoxia is a major cause (of PVCs) and cigarette smoke actually contains a fair amount of HCN (which causes anoxia). This was manifest by my red-cell count being much higher than normal despite living at or below sea level. It seems to me that The H2S can could a similar situation (only the dose was larger so the effect is more pronounced).

If it is, indeed like this (and the common antidote suggests this) it should improve over time.

Cheers,

O3

[Edited on 14-5-2008 by Ozone]

blazter - 14-5-2008 at 18:20

I work in an industrial setting where H2S is generated often. Even with all the safeguards like wall mounted monitors, its possible to get a whiff that will start to deaden the sense of smell. I have experienced the change in odor from "rotten egg" to "sickeningly sweet" which presumably occur before total loss of smell and finally unconsciousness.

We have pager sized H2S monitors that vibrate/flash/beep when exposed to 10ppm H2S. These units can be bought for a few hundred dollars, and if you must play with H2S they are worth it. It's important to remember that humans can detect H2S odor in parts per billion when the toxicity range is in the parts per million. Humans probably developed this trait through natural selection - those who were not averse to the odor of H2S likely died off long ago.

The company's policy for dealing with gas is to carry the personal detectors and have a gas mask on hand for escape only when the detector goes off. The gas masks are the full face type with a carbon style filter, about the size of a large Spam can. For people who must work in the gas - operations crew going back in to close valves etc, must wear full SCBA dress and work in pairs.

Anyways, H2S can be scary stuff to work with even if you have all the necessary supplies to mange the risk.

Magpie - 14-5-2008 at 19:01

Quote:

The result is a skipped beat followed by a really hard one (almost a s freaky as the skipped beat).


I know exactly what you mean here. I became subject to arythmia when I was 36 years old. I quit an overly stressful job and it greatly subsided. I have lived with it for decades. I usually get it now only when overstressed by physical exertion, too much caffeine, or not enough sleep. I understand that some forms of arythmia can kill you.
Quote:

Anyways, H2S can be scary stuff to work with even if you have all the necessary supplies to mange the risk.


What amazes me is that I remember H2S being available from a valved supply hose in a hood when I took general chemistry in college (1960's). What if some clueless freshman had just left that valve open? I don't remember any safeguards, or warnings from the instructor. Now, I believe that for the qualitative analysis tests sulfide is generated in situ using a small amount of thioacetamide.

Klute, I'm glad to hear that you are feeling better and wish you a full recovery. I have played with H2S in my home fume hood. I certainly will think long and hard before doing that again.

[Edited on 14-5-2008 by Magpie]

Klute - 14-5-2008 at 22:26

Thank you all for your concern! I am feeling much better, although i still havea little breathing disconfort, and I pay much more attention to my heartbeat. Curiously, i seem to notice these skips in the evening/night rather than during the day. I guess I'm too busy/occupied at daytime to notice. I still haven't been able to see my doctor, but will do so tomorow.

Magpie, how well did your fume hood handle the gas? Did you get any smell? How much gas was generated/handled? It would be interesting to see how well a good (I insist, a good, as yours :) ) fume hood can handle H2S, as the reference I inspired myself simply states that copious amounts of H2S and H2 are liberated. They simply continu and extract three times with ether. I know publications rarely state the safety conditions or precautions needed, and rely on the readers training/logic sense to do the reactions: ie publications suing BuLi won't advise you do not add water to it or take a sip out of it :). But i suppose they must have worked in conventional conditions, under a good hood with the sash well down, as i can't imagine how else they could have extracted and handled the extracts and the sludge without been exposed.

I'm setting plans for my fume hood, and hopefully will start building it in a month or two when things calm down at work.

Magpie - 15-5-2008 at 10:29

Klute, I generated the H2S for the purpose of making CdS. See this thread:

http://sciencemadness.org/talk/viewthread.php?tid=4676&p...

One of the problems with H2S is that even though we know it is deadly we tend to get careless due to familiarity. I used it in several chemistry classes. At one place I worked they had a tertiary waste treatment process using a rotating biosurface. It was housed in a building with strong forced ventilation. When you walked in the building you could smell the H2S. In fact it could be smelled throughout the surrounding residential neigborhood! This was a public relations problem, and the odor was eventuatally eliminated by adding ppm levels of FeCl3 to the waste stream.

At times I have contemplated making a small amount of KF and KCN. Probababy due to unfamiliarity I fear them more than H2S.

MagicJigPipe - 15-5-2008 at 10:40

Why do you fear KF? Apparently, it is no more toxic than KBr and not much more than KI. Are you afraid of it's hygroscopy that forms semi-corrosive solutions?

[Edited on 5-15-2008 by MagicJigPipe]

unionised - 15-5-2008 at 10:51

How well do the symptoms in the original poster's experience tally with a panic attack. Here's a description from wiki.
"Descriptions
Many who suffer panic attacks state they are the most frightening experiences of their lives. Sufferers of panic attacks report a fear or sense of dying, "going crazy", and/or experiencing a heart attack, feeling faint, nauseous, "flashing vision", or losing control of themselves. These feelings may provoke a strong urge to escape or flee the place where the attack began (a consequence of the sympathetic "fight or flight" response).

A panic attack is a response of the sympathetic nervous system (SNS). The most common symptoms may include trembling, dyspnea (shortness of breath), heart palpitations, chest pain (or chest tightness), hot flashes, cold flashes, burning sensations (particularly in the facial or neck area), sweating, nausea, dizziness (or slight vertigo), light-headedness, hyperventilation, paresthesias (tingling sensations), sensations of choking or smothering or derealization, or the feeling that nothing is real. These physical symptoms are interpreted with alarm in people prone to panic attacks. This results in increased anxiety, and forms a positive feedback loop.[4]
"

And how well do they tally with the observation made about someone who was affected by H2S?

"I saw only one case of H2S poisoning. It was caused by leaking sluice valve and man standing close to it took a deep breath.
He made few steps (propably he wanted to run) and fell down, loosing consciousness.
Fortunately, after ~10 seconds he awoke, got up... and it is all story. "
(from earlier in this thread)

I'm not certain this post is about a case of H2S poisoning.


[Edited on 15-5-08 by unionised]

MagicJigPipe - 15-5-2008 at 10:54

That has certainly happened to me after I thought I had been overexposed to something. However, the symptoms of the "panic attack" disappear within an hour. His symptoms did not.

Klute - 15-5-2008 at 12:12

I guess there was a part of the panic when I realized I was poisoined, but it's the pronouced symptoms that got me worried. I have already suffered panic attacks under hallucinogens, been in a severe car accident and had a friend die of an overdose in my arms, and most lately deeply cut my left hand open, all situations were panic get hold of you, and this definatively wasn't just a panic attack, there was a very strong "sickening" side to it, i really felt poisoned, and not far from fainting (blurred vision, getting very light colors, about to trip), while I have never fainted in my life before. The irritations of the mouth, nose and lungs wasn't psycological either.

the fact the symptoms quickly diminished after adminitering the nitrite, while I was actual even more anxious after, because I was scared it would cause even more bad effect in case of a bad dosage, leaves me no doubt.

I obviously don't deny the strong hand shaking and the increased heart beat was at least in part du to the panic, but the hand shaking is one of the first things that made me feel something was going wrong, not the other way around.

unionised - 15-5-2008 at 22:07

"That has certainly happened to me after I thought I had been overexposed to something. However, the symptoms of the "panic attack" disappear within an hour. His symptoms did not. "
The symptoms of H2S poisononing seemed to disapear in seconds.

Klute - 16-5-2008 at 04:53

Um, no they didn't. They disappered easily 30min after exposure, once the nitrite was administred. They effectively called down once I was outside and got fresh air, 5min after I felt like I wasnt' going to faint after all. But, beleive me, things didn'yt just wear off from that point on.

In any case, no matter how much I type, I will not be able to fully describ the feeling it was. the description of hands shaking during a panic attack and during an intoxication are exactly the same when writen down, but as are the description of feeling relaxed, be it after a massage or after smoking a joint, while the feeligns are totally different. If, from what I wrote, you consider this to be a simple panic attack, well, too bad. If one day your are exposed to this gas, something I sincerely hope will never happen, you will be able to see the feeling it is by yourself. I will be able to judge then.

in any case, I just don't want this to make you, or anyone else for that matter, beleive that you can get away easily with H2S, and that you have time to smell it, feel a little dizzy, then go away. Just don't take the chance. I will never know what would have happened if I hadn't administered the nitrite, perhaps things would have calmed down after 15min, perhaps not. take it the way you want, but be carefull.

Jor - 16-5-2008 at 06:38

Quote:
Originally posted by MagicJigPipe
Why do you fear KF? Apparently, it is no more toxic than KBr and not much more than KI. Are you afraid of it's hygroscopy that forms semi-corrosive solutions?

[Edited on 5-15-2008 by MagicJigPipe]

KF is actually very toxic. Maybe even more toxic than NaF (the solubility of NaF is way below the KF solubility), although the MSDS do not say KF is more toxic. Ofcourse, this is when you ingest it, wich is highly unlikely. But comparing KF to KBr is a bit odd.

Oxford MSDS states KF as 'Harmful'. I guess they do that, because there hasn't been much research on KF toxicity. As you can see on other MSDS, when not much data is available, they will call a substance 'Harmful'.

And KBr is quite harmless, maybe a little more toxic than KCl of KI. I once read a full research project focussing on bromide and bromate toxicity. KBr was only harmful in large dosis.

[Edited on 16-5-2008 by Jor]

MagicJigPipe - 16-5-2008 at 11:32

Fluorides are only harmful in "large" doses as well (over 1 gram), apparently. Bromides produce CNS effects and, in larger doses (a few grams) can cause coma and sometimes death. After reading about it's pharmacology I learned that it's half-life is 4-6 weeks, which, in theory, would pose a significant accumulation risk if you work around it often (apparently it is still used to treat siezures and rarely as a sedative).

I just think it would take a rather large mishap to be killed or even harmed with fluoride salts (excluding chemical reactions). I wonder how much fluoride is in a tube of toothpaste? Enough to kill someone if they ate it? I doubt it but who knows...

[Edited on 5-16-2008 by MagicJigPipe]

Magpie - 16-5-2008 at 15:07

I said:
Quote:

At times I have contemplated making a small amount of KF and KCN. Probababy due to unfamiliarity I fear them more than H2S.


I agree that KF per se, while a poison, is not what concerns me. It is the possible breathing of HF vapors, or getting HF solutions on my skin, during the synthesis of KF that I fear. Also, once you have the KF and/or KCN then you have the burden of safe storage to make sure that it never inadvertantly comes in contact with acid. This could be especially troublesome if you weren't aware that it had happened.

MagicJigPipe - 16-5-2008 at 15:51

Especially if you're one of the unlucky ones who can't smell HCN.

chief - 28-10-2008 at 05:45

I have a rat-problem, _now_. And poison does not come into account, because of the stinking and rotting cadavers in the holes !
The rat(s ?) are under a 2-ton brickwall-waste, and their "home" has at least maybe 4-5 visible entrances. Now I heavily think of what to do ...
because it's also a indoor-problem !


[Edited on 28-10-2008 by chief]

sparkgap - 28-10-2008 at 06:30

I don't know about you guys, but these two surprised me:

http://www.jneurosci.org/cgi/reprint/16/3/1066.pdf

and

http://www.jhu.edu/~gazette/2008/27oct08/27hydrogen.html

sparky (~_~)

Ephoton - 20-11-2008 at 01:48

ive made HCN and got a small dose of it. very simular to what klute explained
for H2S.

was not fun thats for sure.

was very early in my chem days that I did this.

I was trying to make sodium cyanide by reacting ferrocyanide with H2SO4 then
bubbling the HCN gas into NaOH.

all was going well till the time I opened the reaction flask for clean up.

I would only do these type of reactions with a full breathing apiratice now and
a good fume hood as well.

even then I would be very carefull.

does´nt lead acetate work as an indicator for H2S ;)

oxide - 25-1-2009 at 05:22

I don't mind the dangers of chemistry, especially not them of poisenous gasses,
but during my experimenting with H2S in a closed room and bad smell of rotten eggs, I've not encountered numbing of senses or
scary intoxication symptoms and the procedure was a stinky 12 hours experimental of producing HI.

Another interesting part, though it doesn't belong into this thread (can't find the one about Zn/Acid reduction), is, to bubble H2S through the post reaction mix.

There should be a ZnS percipitate be formed and fall out of solution and the acid and product regained. I've read this in an old patent.

hissingnoise - 25-1-2009 at 05:49

Quote:
Originally posted by oxide
I don't mind the dangers of chemistry, especially not them of poisenous gasses,


That kind of complacency is often terminal.
Get real!

nitroglycol - 30-1-2009 at 21:14

When I was a kid (back in the late 1970s) I had one of those Thomas Salter chemistry sets. One of the experiments involved making a couple of "measures" of FeS (the "measure" was a little spoon with a bowl around 5 mm across) from the elements, then grinding it up and heating it with sodium bisulphate. Presumably the amount made was tiny, but it seems weird that a kid's chemistry set told you how to make something more toxic, dose for dose, than HCN.

aonomus - 25-11-2009 at 13:32

I know this is an old thread, but after my experience earlier this week (2 days ago), I feel like I have to share.

As mentioned earlier, thioacetamide has supplanted H2S gas for qualitative analysis in teaching labs almost exclusively due to safety issues, however, H2S can still be generated by subsequent steps. I work as a lab assistant for university teaching labs, and outside of my regular duties I was asked to run through an experiment (cation identification) to see how long it would take, so that the experiment could be run during normal lab hours for undergraduate students.

So normally, Pb2+ and Cu2+ (amongst others, only Pb/Cu were present as sulfides) get precipitated as sulfides when H2S gas is bubbled through a solution, or, when thioacetamide is added and the solution is heated in a boiling water bath. Because the procedure was simply too long, a modification was made (not my decision, requested by professor) and I ran through the experiment again.

The modification was to simply omit Cu2+ from the known (control) and unknown solutions given, however because the thioacetamide solution volume being added wasn't reduced, there was a large excess. The thioacetamide precipitated what remaining lead there was, however due to the excess, and slight acidity in the solution, H2S gas was generated when not expected.

Normally the procedure requires the thioacetamide precipitation of sulfides, followed by centrifugation, then separation. The precipitate is acidified, releasing H2S, and freeing the cations in question (this is done in the fume hood). Once the heating is complete and the solution has cooled (also done in a fume hood), there is no chance of thioacetamide producing H2S gas.

In the modification, the large excess of thioacetamide solution, and slight acidity from a previous step generated enough H2S to deaden my sense of smell, I stopped the experiment and threw everything into the fume hood when I realized this about 1-3 minutes after I noticed my sense of smell had been deadened, and it was faintly 'sweet'. The lab tech had a few fragrant items around (coffee, perfume, etc), none of which I could smell. I started to feel dizzy, and weak, and my hands were only slightly shaky, however knowing the hazards of H2S, She and I went down to health services who checked my blood pressure, heart rhythm, breathing, etc.

I remained for observation and was not sent to the hospital because I did not exhibit symptoms of acute exposure, mainly, no heart arrhythmia, bronchiospasms, no visible irritation of any mucous membranes (eyes, nose, throat), and my heart rate + blood pressure were in normal ranges. After about an hour, my symptoms began to improve, and my heart rate + blood pressure dropped slightly. The doctor suspects that a fair bit of anxiety had to do with the increased heart rate and blood pressure, but since no signs of a large dosage occured (namely due to no heart arrythmia), she wasn't terribly worried.

------------------
Epilogue:
Granted, my exposure was not as extreme as Klutes to warrant a hasty NaNO2 injection, however I did exhibit similar (but not as pronounced) symptoms. I'm surprised at how little it actually takes.

To give some perspective, I used 0.5mL of a 1M solution (0.5mMol) in a large lab with 4 fume hoods at one side of the room drawing air out. Now assuming that about 0.1mMol (according to the original procedure) of Pb2+ was present in the original mixture, after precipitating most as PbCl2, and approximately 0.3mMol Cu2+, that would mean the experiment was designed with a slight excess of thioacetamide in mind, but removing Cu2+ resulted in most of the thioacetamide slowly hydrolyzing in water to H2S over time.

Edit for clarity: I was working at the benches, not in the hoods. The students that might have ended up running this experiment would have been at the benches. Imagine 24 first year undergraduates generating H2S in that quantity.

Two days later and I'm completely fine, I did have a headache for the rest of the day and felt 'drained'. After a good nights sleep however I am feeling well.

My advice is to treat *any* sulfide, or sulfide source with extreme respect. In a 'relatively' confined space, my ~0.3mMol H2S was enough to make me feel bad enough to have to go seek medical attention. Always have your H2S steps planned out where you won't have exposure to them until the sulfides are removed (precipitation or reaction with acid).

[Edited on 25-11-2009 by aonomus]

entropy51 - 25-11-2009 at 16:45

Quote:
I was asked to run through an experiment (cation identification) to see how long it would take, so that the experiment could be run during normal lab hours for undergraduate students
Was this a test tube scale experiment? How much H2S could you have made, worst case?
Quote:
I started to feel dizzy, and weak, and my hands were only slightly shaky, however knowing the hazards of H2S, She and I went down to health services who checked my blood pressure, heart rhythm, breathing, etc.
You walked to student health? Patients with H2S poisoning are horizontal, not vertical and walking.
Quote:
I remained for observation and was not sent to the hospital because I did not exhibit symptoms of acute exposure
That's right, going wee wee in your pants doesn't count.
Quote:
The doctor suspects that a fair bit of anxiety had to do with the increased heart rate and blood pressure
Yup. Fear does that to some people.
Quote:
I'm surprised at how little it actually takes
Get a grip, man. It's H2S, not sarin. If you're awake enough to be worried about it, just go out into the fresh air. I've seen that work, even for people who'd lost consciousness.

aonomus - 25-11-2009 at 17:10

Test tube scale experiment.

No need to be quite so point-by-point snippy though. This has been my first accident beyond things that don't matter... well... ever. Figures it had to be H2S. Different people probably also have different threshold levels for showing symptoms like that.

entropy51 - 25-11-2009 at 17:34

Quote:
Figures it had to be H2S.
WTF. Apparently nobody but anonomus thinks that there was even anything wrong, let alone that it was due to H2S. And you tell us that you're surprised at how little it actually takes? In your case, apparently negligible amounts are adequate.

Test tube scale, in a room with hoods exhausting the room air, even if you were on the bench. How much H2S do you think you could possibly been exposed to? If you had been shut up in a little closet, I might think, well maybe, but not under these conditions.

But at least you didn't go nuts and start giving yourself "antidotes".

Panache - 25-11-2009 at 21:44

I have debated the wisdom of writing my experience into this thread, in case it somehow instils people with a sense of invunerability, however as it is evident people do work with this gas i will share my technique for working with it in a manner that allows one to be safer than one would be otherwise.
It goes without saying that a fumehood venting to somewhere that the gas can be infinitely diluted (ie the atmosphere) is ideal. I understand this is something that is not possible for all people wanting to experiment with this gas.

As you can smell the gas at safe working levels this gives it an inbuilt detection system, in case of leaks. I believe gas masks for working with this gas can actually lead to complacency at times. I firmly believe Klute would have discovered and fixed his leak well before anything untoward had occurred had he not been wearing it. As a fall back, having one slung over ones head, is a sensible approach. The gas however is not toxic enough to kill you instantly, unless you happen to breath it in completely undiluted, which is unlikely, unless you are an idiot.

But the catch is you stop smelling the gas at higher levels, so to circumvent this i kept a small stoppered testtube in my labcoat pocket with some Fes and hcl in it, i would take this out probably every other minute and ensure that by wafting it i could smell it, thus establishing that background level was lower than what is toxic.

If you do encounter the circumstance where you have stopped smelling the gas, put the mask on, calmly, then take your detergent/water solution in a spray bottle(prepared), and spray all the joints on your setup to establish where the leak is, fix it. Then take your 1% NaOH solution in a spray bottle (prepared and ready) and spray the entire contents in to the room, this will take about 5 minutes and your wrist will cramp. Exit the room, shutting the door, relax somewhere until you can smell your little tube again. Re-enter the room, its unlikely you will smell anything, take your little tube out, waft it, you should be able to smell it, continue.
If you cannot, replace your mask, repeat the previous step until you can.

My setup was thorough enough that i never encountered a leak i could smell, people should ensure that after they have setup their glass, they throughly test it for leaks using compressed air/n2/blowing through it, a small spray of detergent in water over each joint will display bubbles in the case of a leak. Finally the exit stream from your glass should bubble through enough caustic solution to neutralise ten times the amount of gas you are expecting.

I also had a nitrite solution, dosed, syringed and ready, an ex-junkie mate ran me through how to find a vein etc and i practised on some silicon tubing, taped onto my forearm, it was fun, not really that easy when you only have one hand. Probably a bit of overkill but it was harmless.

Finally i feel it entirely ridiculous that anyone should belittle or demean efforts of those who are simply attempting to be careful or are concerned regarding their own health or that of others. Legitimate comment could easily be made, if ones feels it warranted in a manner that does belittle and leaves the thread open and inviting for others to comment.

Thank-you for your post Aonomus (i spelt it correctly), i really don't understand the motives behind the aggressive responses you seem to have generated.

There with these few comments taken in you are ready to prepare dimethyl mercury under the bed in your dorm room. Good Luck!!!

Edit-Many of us here have much practical experience with bench setups using gases, if anyone is trying new things and wants a look over the setup they are considering just sketch a quick crappy, but well labeled diagram and post it here, there are many small things that can be problematic if one is inexperienced, likewise there are many ways of simply doing the same thing.



[Edited on 26-11-2009 by Panache]

aonomus - 25-11-2009 at 22:14

Thanks for your response Panache, my only attempt was to voice my concern that once you stop smelling the gas, you don't know how much you are getting dosed, even if it was a 'small' amount. Perhaps my calculations were wrong and somehow I got dosed with more.

I know I was only working on the test tube scale, and not generating H2S as a reagent, but this is an example of how a tiny bit can take you by surprise even for someone that has done more hazardous and complex procedures. I myself was a little complacent, but at least I quickly realized what was happening and left the area.

entropy51 - 28-11-2009 at 13:24

I will say it once more, because I don't want people to believe that they can rescue themselves from a serious intoxication with H2S.

Free medical advice

If you are intoxicated seriously enough with H2S to need an antidote, you will be unconscious. You will not be able to treat yourself.

Corollary: If you are able to think about injecting yourself with an "antidote", let alone really inject yourself, you are not, repeat not, seriously intoxicated enough to need an antidote. Just quickly move to fresh air. If you are able to walk, that's all you need, fresh air.

The real deal

Sodium nitrite is an antidote for HCN, not H2S. There is no evidence that sodium nitrite is effective in treating H2S intoxication. It has been tried, out of desperation, but it doesn't work. An IV injection of NaNO2 itself can be lethal, especially in untrained hands.

JohnWW - 29-11-2009 at 13:24

Entropy51: if that is the case, it is rather surprising that, during World War/Whore 2, from about 1940 to until the death camps were liberated by the Allies in late 1944 and early 1945, the Nazis did not think of using H2S, generated by acid hydrolysis of a metal sulfide, in their gas chambers at Auschwitz and elsewhere to kill Jews and other political prisoners, instead of using HCN generated from hydrolysis of Zyklon B. H2S would have been even more deadly, and with much less possibility of any antidote. Also, I wonder if any of the Jewish prisoners in Auschwitz etc., and people in the Polish Resistance outside trying to help them, tried to obtain and smuggle NaNO2 into the camp.

len1 - 29-11-2009 at 14:03

H2S wasnt considered that scarry until the over-reaction to chremicals in the last decade or so - I remember making it was part of my school lab and kids chemistry set also. FDor that reason alone I dont believe it ever entered the Nazis head.

But the whole thing was actually carefully engineered - its not easy to kill 3500 a day - ten train loads of people. With gas time of 30mins they needed a gas which could be cleared in 20mins so the workers could get in and haul the bodies to the crematorium, with the chamber ready again in 2hrs. Hence giant fans started working after 30mins exposure. The human nose is so sensitive to H2S that it would have been impossible to get the air clean, ready for the next lot, as if nothing had happened. The whole camp would have reeked of H2S, sulphur covered the walls, the next set of victims would be hard set to convince theyre about to take a shower.

As for NaNO2 antidote - 30 minutes is a huge overdose - this salt is quite toxic, and designed to be taken in after exposure ceased, I dont believe the human body can run as a reagent vessel taking in cyanide in the lungs, being oxidized by continuos injection of the nitrite ion. Having said that, the single digit people who survived the gassing were shot.

annaandherdad - 4-11-2011 at 14:39

I realize this thread is old. I just wanted to add that I worked with a chemistry set in the 1960's and production of H2S was not considered any big deal. In fact I used to do it every so often to make "stink bombs". I'm not saying this to discount any of the real dangers, but I wonder why there were not more serious incidents before people became so sensitive to safety, ie prior to the 1970's or so.

I recall a chem professor of mine in 1963 (this was in a class on qualitative analysis) saying that H2S was very poisonous but it smelled so bad that no one had ever been known to have been killed by it.

simba - 4-11-2011 at 16:01

Quote: Originally posted by annaandherdad  
I realize this thread is old. I just wanted to add that I worked with a chemistry set in the 1960's and production of H2S was not considered any big deal. In fact I used to do it every so often to make "stink bombs". I'm not saying this to discount any of the real dangers, but I wonder why there were not more serious incidents before people became so sensitive to safety, ie prior to the 1970's or so.

I recall a chem professor of mine in 1963 (this was in a class on qualitative analysis) saying that H2S was very poisonous but it smelled so bad that no one had ever been known to have been killed by it.


Indeed. Its not like HCN that the smell may go unnoticed, or even worse, like phosgene, which the smell may go unnoticed, with delayed symptoms, increasing the risk of a fatal poisoning.

madscientist - 4-11-2011 at 16:25

I do not mean to downplay how scary of an experience it was for Klute, but his symptoms sound like those of a panic attack. I've experienced a few bad ones before and I have never experienced anything so unpleasant and terrifying since. It's very different from a typical bout of severe anxiety ("I'm panicking because I'm completely screwed!"). Instead of the anxiety stemming from an external trigger, it's internal - one freaks out over the symptoms of anxiety. Of course this leads to symptoms worsening exponentially to shocking extremes, including heart rates as high as 180bpm with skipped beats, pins and needles all over the body, muscle spasms causing facial muscles to clench and hands to pull back to a right angle, pale blue color to the skin, and of course a sense of complete TERROR and total conviction that death is imminent, that something is very wrong, that such extreme symptoms could not possibly be the result of simple anxiety... I say this because once a doctor told me it was panic, and not a heart attack, I never had a repeat experience anywhere near as severe. I would not wish it on anyone.

IrC - 5-11-2011 at 00:23

What about building a detector based on the Figaro gas sensor TGS825 Hydrogen sulfide (5-100ppm)? I did using the little Pic PIC12F683-I/P, a TGS825, and a programmer development setup I have. I just like to know these things. Mostly because as madscientist said it was likely more panic attack. It happened to me once. I for work related reasons reversed engineered the 'enemy' electronics and I typically had a bucket of methylene chloride sitting around with some board or other in it all the time and I never worried about things. Several years of doing this later I studied up on the depotting solvent and learned it was flooding my blood with monoxide. A few months later I started having severe panic attacks which actually forced me to stop using the chemical. I never have had it since. I know in my mind for years I had no trouble being most cavalier with the stuff but after too much study of how breathing it results in nasty things in your blood I just could not use it anymore. Not only that but on a trip taking an old International truck from Phoenix to Billings with an exhaust leak so severe I was too sick, dizzy, and nauseated to drive halfway through Idaho. I went to an emergency room and all they did was stick a red laser sensor on my finger and say 'gee your blood O2 looks really high'. Stupid doctor I thought. I asked him since all their device was doing was shining a laser through my finger to measure how red my blood was how the hell would they know it I was dying or not? I actually had to explain to the doctor how his equipment worked and relate this to the fact that CO binds the blood making it even redder than normal. So the closer to death you are the better they think you are! I explained to him that only by testing arterial blood gasses could they know. This guy had a medical degree and neither him or his nurses understood how or why their equipment worked nor did they understand they were in error on the side of killing their patients. Needless to say after breathing fresh air for 3 hours I felt better anyway so I left and slept in the truck with the motor off until morning when I went around getting the parts to fix the exhaust system myself allowing me to finish my trip with no further illness.

About a month later I started having similar panic experiences with CO in general. At home even thinking about my furnace started being a problem. I started researching gas sensors (at the time there were none at Walmart or similar places for sale) and came upon Figaro. I ordered a CO sensor and when it came in the mail completed my first warning alarm device the same day. I designed it to either plug in the wall or use a cig lighter plug so I could take it on cross country driving trips. Still have it. I designed in a sensitivity control to where it will even detect someone smoking in the room from the monoxide. I will say it was surprising to learn in the winter you have more CO floating around than you might realize, but it did explain some of the red I see in peoples faces in the winter.

No mind over fear approached worked for me. Science over fear did. This was around 91 or 92 and Figaro was just starting so CO was about the only sensor they had. Today they have many covering a large number of various gasses. Nothing beats the calming effect of actually measuring and knowing for sure the types and amounts of gasses around you.

Right now they list sensors for:

LP-Gas/Propane (500-10000ppm)
Natural gas/Methane (500-10000ppm)
General combustible gas (500-10000ppm)
Hydrogen (50-1000ppm)
Carbon monoxide (50-1000ppm)
Ammonia (30-300ppm)
Hydrogen sulfide (5-100ppm)
Methane and Carbon monoxide
Alcohol, toluene, xylene (50-5000ppm)
CFCs (HCFCs and HFCs)
R-22, R-113 (100-3000ppm)
R-21-R-22 (100-3000ppm)
R-134a,R-22 (100-3000ppm)
Other refrigerant gases
Indoor Pollutants
Carbon dioxide
Air contaminants (<10ppm)
Automobile Ventilation
Gasoline exhaust
Gasoline and diesel exhaust
Volatile vapors from food (alcohol)
Water vapors from food
Oxygen

Something to think about. As cheap as these sensors are now and considering how simple an alarm circuit is to build I think it makes sense to have such a capability in your mad science lab.

But that is just me.

Edit: I guess a link would help.

http://www.figarosensor.com/gaslist.html


[Edited on 11-5-2011 by IrC]

Endimion17 - 5-11-2011 at 03:15

Klute wrote that he used "50mg in 1mL" of sodium nitrite. Did he use 1 mL shot containing 50 mg? That's 4.76% solution (0.05 g of the salt in 1.05 g of the solution), and the appropriate percentage is 3%, used as IV push of 0.35 ml/kg.
Na-nitrite is usually given as prepared 10 mL 3% shots during 3 minutes, and it has to be pure salt, not this 90% he mentioned.

Am I mistaken to feel like he could've done less harm to his veins or his heart/brain if he just went outside, breathing deep and calm?
If a person is conscious enough to prepare a solution and administer it intravenously, I'd say the intoxication is not great, and fresh air is enough.
Sodium nitrite shots are typically given by ER personell upon finding someone lying on the floor unconscious or twitching, and there's a stink of H<sub>2</sub>S or similar blood poison (HCN). Or when there's evidence to support cyanide salt intoxication, etc.

I think he just had panicked and that could've killed him.
If one can prepare a nitrite shot, one can build a freaking fume hood, too.

[Edited on 5-11-2011 by Endimion17]

White Yeti - 5-11-2011 at 08:13

That's quite an accident. I've worked with H2S before as well, small quantities though. I wondered if I should handle it in a fume hood or outside. I decided to handle it outside, because I was working with very small quantities.

I made an H2S generator that could be loaded in less than 10 seconds to limit exposure to the gas.

The problem came when I had to open up the generator, and when I had to collect the product when the synthesis was over. Some gas was still in the generator and some un-popped bubbles floated above the product.

The smell was atrocious, but the concentration was low enough not to knock out my sense of smell (I thought). The whole time I carried around a vial of vinegar to be sure my sense of smell was not knocked out.

Then I smelled the vinegar I brought along, and smell was only half as strong. That's when I knew I had to get the hell out of there. Then my hands started shaking, more from fright than from anything else.

I'm curious though, how long did it take for your sense of smell to recover? It took me an entire day before I could smell anything properly.

I would also advise anyone even THINKING about doing this, to reconsider.

@ Endimion17, having worked with this before, I can assure you that "fresh air" is hard to come by when you lose control of H2S. It hugs the floor, so you'd have to climb a tree (if you're outside) to get away from it. If you did this in a building you'd have to find a safe place upstairs, or on the roof. Even worse, it hugs the bottom of you lungs, so you need to do a handstand against a wall to get every last bit of gas out of your lungs. Then again, it's hard to do a handstand when your hands are shaking.

H2S for suicide

annaandherdad - 6-11-2011 at 11:31

A few months ago, before I knew about this forum, I read an article in the New York Times about a recent fad in Japan of committing suicide. I'm not sure I remember exactly what was in the article and what I learned about it after some internet research, but the article made it clear that there had been some suicides using some kind of gas, that sometimes there were worries that neighboring apartments and houses would be affected by the gas, and that the author of the article didn't want to reveal the recipe for fear of facilitating more suicides. Then I took some clues from the article and googled on suicide methods and put the pieces together, which made it clear that it was H2S that was being used, and that it was being produced by mixing toilet bowl cleaner (for the HCl content) with some kind of sulfur compound. I was thinking to myself, if they only knew how easy it is to make FeS. I also found it creepy looking at one of the suicide web sites, there were people who were so depressed they were begging for help in doing it cleanly.

I'm not sure I would use H2S if I wanted to kill myself, I always assumed CO would be the most painless.

White Yeti - 6-11-2011 at 12:44

Quote: Originally posted by annaandherdad  
I'm not sure I would use H2S if I wanted to kill myself, I always assumed CO would be the most painless.


It's also scary how easily CO can be generated. The dehydration of formic acid via H2SO4 will yield appreciable amounts of CO. There are a million ways to die, H2S is just a smelly one.

A simple google search can turn up more info than a suicidal person should know. These people are stubborn, the author's efforts were in vain.

I have a friend who has an old dog in pain, but he does not want to put him to sleep because it's outrageously expensive >$500.
I told him that formic acid with H2SO4 yields CO, so he can put out his dog without paying someone else to do it.

annaandherdad - 6-11-2011 at 13:03

Yes, a guy associated with one of the research groups where I work was recently killed by CO from a faulty heater. I don't think it was at home, I think it was out at some research station.

Endimion17 - 6-11-2011 at 15:10

Quote: Originally posted by White Yeti  
@ Endimion17, having worked with this before, I can assure you that "fresh air" is hard to come by when you lose control of H2S. It hugs the floor, so you'd have to climb a tree (if you're outside) to get away from it. If you did this in a building you'd have to find a safe place upstairs, or on the roof. Even worse, it hugs the bottom of you lungs, so you need to do a handstand against a wall to get every last bit of gas out of your lungs. Then again, it's hard to do a handstand when your hands are shaking.


No, you don't have to climb a tree. There's always a breeze.
I'm curious how is it possible to create so much hydrogen sulphide. I always had trouble with that and my apparatuses were neat and tight. No wasting, and if I need to open something, I did it outside.
I simply don't understand how can these things happen unless someone has a faulty gas cylinder. Where do you people get so much acid soluble sulphides?

And no, it does not hug the bottom of the lungs. That's an annoying myth associated with breathing helium and sulfur hexafluoride.
Lungs are not empty bags to allow gases collecting inside. They're made of porous tissue and if they're filled with a foreigh gas, few generous breaths are enough to get rid of them.
The handstand thing is completely unneccessary.
Quote: Originally posted by annaandherdad  
A few months ago, before I knew about this forum, I read an article in the New York Times about a recent fad in Japan of committing suicide. I'm not sure I remember exactly what was in the article and what I learned about it after some internet research, but the article made it clear that there had been some suicides using some kind of gas, that sometimes there were worries that neighboring apartments and houses would be affected by the gas, and that the author of the article didn't want to reveal the recipe for fear of facilitating more suicides. Then I took some clues from the article and googled on suicide methods and put the pieces together, which made it clear that it was H2S that was being used, and that it was being produced by mixing toilet bowl cleaner (for the HCl content) with some kind of sulfur compound. I was thinking to myself, if they only knew how easy it is to make FeS. I also found it creepy looking at one of the suicide web sites, there were people who were so depressed they were begging for help in doing it cleanly.

I'm not sure I would use H2S if I wanted to kill myself, I always assumed CO would be the most painless.


Those are the infamous "detergent suicides" that became popular in Japan.
We had one case in Croatia almost exactly a year ago. A guy was found dead in car labeled with warnings in the middle of a field. The car was loaded with the gas produced by a mixture in buckets inside the car.
I sincerely doubt it was a clean suicide because his finger was found on a street in another city and one lady saw him wandering around with a bloody hand. He supposedly told her there's no sense living without a finger. :(
I don't have any updated information, but the whole case was extremely weird and upsetting. He was quite introverted, as I learned.

[Edited on 6-11-2011 by Endimion17]

White Yeti - 6-11-2011 at 15:45

Quote: Originally posted by Endimion17  
There's always a breeze.
I'm curious how is it possible to create so much hydrogen sulphide...Where do you people get so much acid soluble sulphides?
[Edited on 6-11-2011 by Endimion17]


You'd be surprised with how long the rotten egg smell sticks around, even with a slight breeze. Stupid as I am, I chose one of the worst days to perform the synthesis, 0 wind. It took about half an hour for the smell to disappear.

To answer to your second question:
You can create VERY large quantities with Al2S3. I performed a synthesis with about a gram of Al2S3, which when reacted with water can generate about half a litre of H2S, enough to kill several people.

Most people opt for the classical FeS+HCl generator, I prefer the H2O+Al2S3 alternative.

SM2 - 24-7-2012 at 13:00

Wanted to share with every one, another (biological use) for H2S. Sorry link;

http://www.ted.com/talks/mark_roth_suspended_animation.html

White Yeti - 24-7-2012 at 15:04

Yes, H2S can be used for inducing suspended animation. But the guy doesn't give much details about his liquid version of H2S that can be delivered to a patient intravenously.

Does anyone have any guesses as to how one would accomplish such a feat?

SM2 - 24-7-2012 at 16:50

If my memory serves me correct, it was a combination of inhaling low concentrations in air, accompanied by freezing of the body. Timing, order, and a number of variables were all important factors for success. There had been many failures in the past.

liquidlightning - 26-7-2012 at 16:05

Wait, isn't intraveinous sodium nitrite used to treat cyanide poisoning? I had no idea it also worked for H2S.

SM2 - 26-7-2012 at 16:40

Quote: Originally posted by liquidlightning  
Wait, isn't intraveinous sodium nitrite used to treat cyanide poisoning? I had no idea it also worked for H2S.


More elegantly, and more easily titratable. And also less risk of neoplasm, they use Amyl Nitrite, commonly known as poppers. Who said NaNO2 was used to treat CN- intoxication? I guess both substitute in RBC's, but different mechanism.

I don't think you are serious, but I may be wrong.

SM2 - 26-7-2012 at 16:42

Quote: Originally posted by White Yeti  
Quote: Originally posted by Endimion17  
There's always a breeze.
I'm curious how is it possible to create so much hydrogen sulphide...Where do you people get so much acid soluble sulphides?
[Edited on 6-11-2011 by Endimion17]


You'd be surprised with how long the rotten egg smell sticks around, even with a slight breeze. Stupid as I am, I chose one of the worst days to perform the synthesis, 0 wind. It took about half an hour for the smell to disappear.

To answer to your second question:
You can create VERY large quantities with Al2S3. I performed a synthesis with about a gram of Al2S3, which when reacted with water can generate about half a litre of H2S, enough to kill several people.

Most people opt for the classical FeS+HCl generator, I prefer the H2O+Al2S3 alternative.


Had you reacted that with methanol, would you have made methyl mercaptan? Can you share your facile aluminum sulfide synth. thanks.

liquidlightning - 26-7-2012 at 17:18

Quote: Originally posted by Fennel Ass Ih Tone  
Quote: Originally posted by liquidlightning  
Wait, isn't intraveinous sodium nitrite used to treat cyanide poisoning? I had no idea it also worked for H2S.


More elegantly, and more easily titratable. And also less risk of neoplasm, they use Amyl Nitrite, commonly known as poppers. Who said NaNO2 was used to treat CN- intoxication? I guess both substitute in RBC's, but different mechanism.

I don't think you are serious, but I may be wrong.


Here's a link. I am serious. http://en.wikipedia.org/wiki/Cyanide_poisoning#Treatment_of_...

SM2 - 27-7-2012 at 05:55

wanted your synth for Al2S3, mainly. Is it potentially an explosive sulphide?

blogfast25 - 27-7-2012 at 08:33

Quote: Originally posted by Fennel Ass Ih Tone  
wanted your synth for Al2S3, mainly. Is it potentially an explosive sulphide?



Al2S3: direct union of elements in a crucible. Light stoichiom. mixture with Mg ribbon or such like. It’s quite spectacular. Al2S3 then solidifies into fairly soft material (much softer than Al2O3, quite smelly (H2S). With water, H2S is slowly generated, faster with dilute acids. It’s not at all explosive.

This reaction is also used as a heat booster for technical Si via silicon thermite.

AJKOER - 27-7-2012 at 09:40

Quote: Originally posted by chief  
I have a rat-problem, _now_. And poison does not come into account, because of the stinking and rotting cadavers in the holes !
The rat(s ?) are under a 2-ton brickwall-waste, and their "home" has at least maybe 4-5 visible entrances. Now I heavily think of what to do ...
because it's also a indoor-problem !


First, I will state it is a bad (and dangerous) idea to concoct poisons yourself. But, if you nevertheless decide to do something on your own, I would point you (I have no professional background or experience in extermination) in the direction of Copper (II) Oxygen Chloride, 3Cu(OH)2.CuCl2, or Basic copper sulfate, CuSO4.3Cu(OH)2 H2O, or Copper ammonium carbonate, all of which are used in fungicides (after carefully formulation with dispersive and filler agents). FYI, here are some reactions between Hypochlorous acid and Copper forming 3Cu(OH)2.CuCl:

HOCl + 2 Cu --> Cu2O + HCl

2 HOCl +2 Cu --> Cu(OH)2.CuCl2

4 HOCl + 2 Cu2O --> 2 CuCl2.Cu(OH)2 + O2 (g)

An interesting route to preparation would be to add copper filings to a dilute solution of Sodium bisulfate and Bleach (NaClO) forming HOCl. Any Cu(OH)2.CuCl2 formed could be converted into Basic copper sulfate. Also, some comments from "Modern inorganic chemistry" by Joseph William Mellor:

"R. Chenevix notes the ready solubility of cupric oxide in chlorine water, and P. Grouvelle found that the soln. obtained by passing chlorine into water with cupric oxide in suspension possessed bleaching properties, and these were retained even after the soln. had been boiled for a quarter of an hour. A. J. Balard found that the distillation of P. Grouvelle's liquor furnished some hypochlorous acid and a green oxychloride, 3CuO.CuCl2.4H20, was formed in the retort. A. J. Balard prepared a soln. of cupric hypochlorite by dissolving cupric hydroxide in hypochlorous acid. It is also made by the action of cupric sulphate on calcium hypochlorite. A. J. Balard found that copper filings are partially dissolved by hypochlorous acid, the soln. after standing some time contains cupric chloride, and deposits a green pulverulent cupric oxychloride."

Here is a paper describing the preparation of Basic copper sulfate, "The Preparation and Effectiveness of Basic Copper Sulphates for Fungidical Purposes", Link: https://docs.google.com/viewer?a=v&q=cache:fsGty_h63WkJ:...

Copper salts cited above are not overly toxic to people (see http://pmep.cce.cornell.edu/profiles/index.html and search under CuSO4, or go directly to http://pmep.cce.cornell.edu/profiles/fung-nemat/aceticacid-e... ), but certainly use gloves and limit inhalation. Per Wiki at http://en.wikipedia.org/wiki/Copper_toxicity "With an LD50 of 30 mg/kg in rats, "gram quantities" of copper sulfate are potentially lethal in humans." However, Cu salts can apparently be deadly to fish, dogs and lower organisms including fungus. My attention to this fact occurred (on another website) when someone was asking how to cleanup a fish tank after an accidental copper poisoning that killed 'everything' in the tank. Source was a new brass fitting (a copper alloy) that reacted with an ammonia buildup in the fish tank's oxygen rich water attacking the brass and producing a soluble and apparently very toxic Copper compound (a guess, Copper ammonium carbonate).


[Edited on 28-7-2012 by AJKOER]

SM2 - 29-7-2012 at 12:27

Quote: Originally posted by blogfast25  
Quote: Originally posted by Fennel Ass Ih Tone  
wanted your synth for Al2S3, mainly. Is it potentially an explosive sulphide?



Al2S3: direct union of elements in a crucible. Light stoichiom. mixture with Mg ribbon or such like. It’s quite spectacular. Al2S3 then solidifies into fairly soft material (much softer than Al2O3, quite smelly (H2S). With water, H2S is slowly generated, faster with dilute acids. It’s not at all explosive.

This reaction is also used as a heat booster for technical Si via silicon thermite.


Thank you! So would Al2S3, or better yet, zinc sulphide, react w/ methanol to yield the primary mercaptan? zinc sulphide more robust? how's the synth go or recommended (ghetto). Please, and thanks mucho gracious.

blogfast25 - 29-7-2012 at 12:55

No idea about mercaptans, never really thought about it much. Al2S3 is definitely the more reactive of the three mostly in use in H2S generators (Al2S3 > ZnS > FeS).

With methanol H2S and Al methoxide should be formed, not MeSH:

Al2S3 + 3 MeOH ====> 3 H2S + Al(MeO)3.

I think.

SM2 - 29-7-2012 at 15:25

I imagine PS5 plus the alcohol would render a thiol. ?

blogfast25 - 30-7-2012 at 05:00

You mean P2S5? No idea...

SM2 - 30-7-2012 at 07:36

Quote: Originally posted by blogfast25  
You mean P2S5? No idea...




Yais. Not that just anyone would be able P2S5, but with methanol? Methyl Mercaptan?

SM2 - 30-7-2012 at 09:32

I used TFSE, and got many an insight, tnx.

Zan Divine - 30-7-2012 at 14:24

Yup, phosphorus pentasulfide gives mercaptans with alcohols.
I don't think this is a popular preparative route, though, probably because of the ubiquitous nature of thiourea. This is used to form isothiouronium salts (from alkyl halides) and then these are hydrolyzed.

Toxcity, toxicity...ahh yes. I was one of the generation whose chemistry career kicked off with the infamous "The Golden Book of Chemistry Experiments". For the uninitiated, this book was THE cookbook for grade school children who wanted to generate chlorine, taste diluted sulfuric acid, make iron sulfide, generate oxygen, burn iron in chlorine gas, generate hydrogen & ignite it and generally run amok throughout the periodic chart. I can't even recall the number of times I drove our entire family outdoors with H2S.

I guess this is the beauty of H2S. It's hard to get poisoned without a mask because the odor is generally intolerable. If it sneaks into you because of partial protection (carbon isn't protection against this gas) you can be on shaky ground.

Some pages back, I noticed someone wondering how we managed to do H2S in the lab. The answer is, with surprising ease. Even in antiquated, deficient fume hoods it wasn't a problem. We had one reaction on our way to dideoxyadenosine where we converted an amide substituted furanose to a thioamide in a 12 L flask filled with ethanol saturated with H2S. Workup started with filtration using 2 L filtering funnels and thus presented a large liquid interface to the atmosphere. Even with crappy hoods (I had OSHA visit them over this very issue...they were quite ruffled...oops...I mean maniacally incensed) we had no issues.

It's funny how effectively familiarity can breed contempt. I don't give toxins a second thought until they are way worse than cyanide or H2S. The scarriest lab toxin to me is bis(chloromethyl)ether (anybody who uses chloroacetyl chloride ought to pay attention). Perfect carcinogen. Easily made anywhere HCL meets HCHO, volatile, perfect "bite" size and window of hydrolytic instability to cross-link your DNA and dangerous at levels that most lab equipment can't even detect. If I recall corectly, a Ni63 detector fitted to a gc was the detector of choice.
 Pages:  1