Sciencemadness Discussion Board

Fume Cupboard- Ducted or Filtering

Picric-A - 24-8-2009 at 12:52

I own a Clean Air recuircuilating fume cupboard. My school gave it to me around 4 months ago, brand new, and since then i have used halogens and NO2 in it and has been great at filtering them.
My only problem is Clean Air Ltd. havnt respended to my email in which i asked them to send me a compatability table of what the activated carbon filter will remove and what it wont. Does anybody happen to know? I want to use gasses like SO2, NH3, SO3 ect. but i dont know if i will just end up gassing myself out with them...
Should i just sell this fume cupboard and buy a ducted variety? this would mean ugly and expencive ducting and harmful fumes to the enviroment but does this outwheigh the cons of a filter fume hood.

Does anyone else on this board own a purchased fume cupboard and if so what type? care to tell us how you find it?


entropy51 - 24-8-2009 at 14:24

The main recommendations that I have seen for ductless fume hoods with absorption filters is that they are intended only for removal of nuisance odors and not for removal of toxic gases and vapors. I certainly wouldn't depend on one for NH3, H2S, CO etc. (or any flammable vapor) unless there was a duct to outside air following the filter.

Recirculating the exhaust of a fume hood violates most of the safety codes for fume hood performance.

Here is a link to a review by the US National Institutes of Health safety group, for what it's worth. Hope this helps.

kclo4 - 24-8-2009 at 14:30

Not to sure wtf mine is, but I guess you'd call it "ducted" though its really just a nice box with a motor off to the side with a 2-3" wide hose which I've tossed out the window... :D
It does what it needs to do, Its motor is noisy, and might be a little bit on the weak side but it works fine for me, though i haven't extensively tested my fume hood for effectiveness, since I never really deal with super-toxic chemicals, and haven't been to worried about an occasional scent of SO2, NH3, etc.

One method might be to test it. Surely you could do small quantities of each relatively non-toxic substance and see how bad it gets. Or test for it. See if NH3 gets past it by having a an open bottle or wet sponge of HCl by the air that leaves - does it get smokey?

How often do you have to replace the activated carbon or how does it work exactly? Maybe it has water that washes it? I've never looked to much into that type before.

Nature can handle those types of gases just fine, think of how much chlorine and bromine swimming pools give off, SO2, NH3, SO3, NO2 etc turn into fertilizers for what its worth, which I'm sure some plants would enjoy.
I'm not saying all chemicals let go are fine though, some I'd be very worried about.

Edit: you may want to consider jimmy-rigging something using an old swamp cooler fan? I've been consider doing something like this for a while. Old swamp coolers are given away like kittens too, so that is a real bonus. Check out a metal dump/recycling place you'll find a few I'm sure.

[Edited on 24-8-2009 by kclo4]

Picric-A - 24-8-2009 at 14:44

The 18kg filters for myn should be replaced every 2 years however seeing as i will probably use it for 2 months solidly a year i decided i will change it every 3-4 yrs...
@entropy- that article scared me! makes m hood sound useless :( i guess it was written in 2005, hopefully technology has become more advanced since then!

entropy51 - 24-8-2009 at 14:51

Quote: Originally posted by Picric-A  
@entropy- that article scared me! makes m hood sound useless :( i guess it was written in 2005, hopefully technology has become more advanced since then!

You are kidding, right? Don't bet your lungs on it. You did see that a large spill will overwhelm the filters? What about a runaway reaction?

I looked at ductless hoods years ago and decided that they are indeed useless. They're intended for medical technicians who take the cap off a bottle of ethanol or xylene, not for serious chemists.

kclo4 - 24-8-2009 at 14:55

You could probably sell it for a decent amount of money, and use that money to buy a useful fumehood. :D

entropy51 - 24-8-2009 at 15:01

Quote: Originally posted by kclo4  
You could probably sell it for a decent amount of money, and use that money to buy a useful fumehood. :D

Just don't let the potential buyer see that paper I posted! Don't buy a hood, they're not hard to build.

Magpie - 24-8-2009 at 15:02

Ductless fume hoods seem similar to a gas mask to me. The filters and absorbents are specific to a chemical or class of chemicals. Although this may not be your specific equipment, here is a web page from Cole Parmer that gives some information:

From MSA, a cartridge data sheet that also may be informative:

panziandi - 24-8-2009 at 15:24

Not to be too nasty Picric-A but... If you generate copious quatities of HCN form the KCN I GAVE you (along with various others in exchange for this hood!), praps we can find out if the carbon filters really do protect you! Let us know how you get on with the test!

[Edited on 24-8-2009 by panziandi]

kclo4 - 24-8-2009 at 15:52

... wait wait, Picric-A was going to trade you this fumehood for some chemicals but never did?

panziandi - 24-8-2009 at 16:16


Back december or january time! Deal was I was giving him chemicals in exchange for bromine. The bromine never arrived. He also had a fume hood the school gave him that he didnt want because he had one already he just built one and he'd give me it in exchange for chemicals (including KCN that I had sent him! Obviously it was too good to be true, and I had offered money for it) I came home form uni the day it was due, cleaned out a space for it with my grandfather. Waited in all the following day too. Picric-A never replied to my emails or calls, then I realised I'd been done over! Thank god I'd only sent him chemicals and no cash. He thought I was ripping him off claiming that bromine never arrived, he claims it was. In fact when he told me it had been delivered and signed for, I walked around about 3miles of Bristol knocking on doors I thought could be easily mistaken for my address! We now agree to disagree.

All in all this guy is a stupid niave 16year old kid, a joke (I'm sure someone of this board could come out with some good names for this kind of person!). I don't even know why I sent him KCN, he seemed quite a clued individual, clearly not!

Gave me a wake up call not to trust everyone you meet on the net! I suppose I had it coming though, so many good deals in the past with people, a bad apple was due at any time!

kclo4 - 24-8-2009 at 16:30

Oh yeah I vaguely remember reading about this bromine thing, I didn't realize it was between you guys. That seriously sucks.
Well, I guess the least you can do is warn people about such traders.
Is trading very popular?
I occasionally get a few things I don't need, want, or just simply have to much of..etc and I've considered trading them but I don't know how I'd even start. - I guess I probably shouldn't if this happens, but I'd like to be able to get things that I need in my lab...

panziandi - 24-8-2009 at 16:41

I've traded with a few people on this forum, and it's sailed through fine, been very useful for small quantities of things to save having to order 500g! Also sometimes quicker too. Only with this guy have I had a VERY BAD experience. All other people to date have been great. I SHOULD have seen this coming, who offers a fume hood they have from school in exchange for chemicals because they had built their own? Too good to be true, it usually is! I only gave this jerk chemicals because I know how hard it can be to be a young experimenter in search of chemcials, and if you can buy them or get them given to you, it usually saves much mundane chemistry and risk. In my opinion...

stateofhack - 25-8-2009 at 04:54

LOL someone got explaining to do...;)

Picric-A - 25-8-2009 at 07:55

panziandi is just shitstirring, he knows he recieved the Br2 which covered the costs of all the chems (like 4) put together + more....

Back to topic, i got a reply from Clean Air Ltd... looks like im in the clear!

Attachment: My fume hood chemicals compatability.pdf (60kB)
This file has been downloaded 566 times

stateofhack - 25-8-2009 at 08:05

Oh nice that is a wicked hood! How long before you have to change the filter?

panziandi - 25-8-2009 at 08:07

Bottom line is you promised an exchange, you took what I gave you, you didn't send the bromine, I never recieved it and you supposedly sent it recorded delivery and supposedly it was signed for, but certainly nobody in my house signed for a bottle of bromine! Then you allowed me to commute about 80miles to prepare to receive a fume hood, put me and my family out waiting for a no show, and didn't bother to respond to any attempts I made to contact you regarding it, before AND after the no show.

You seem to be dissilussion and are COMPLETELY FULL OF SHIT! I personally would advise NOBODY help this JERK, total shit stirrer who doesn't deserve to be part of the amateur science community! FULL STOP! Get a life!

Picric-A - 25-8-2009 at 08:22

as above, they reccomend every 2 years but becuase i will only use it solidy around 2 months a year i plan to change it every 3-4 years :) the filters are £250 each and pre filters are £100 for a pack of ten :)
So i was right, thankfully technology has improved :) i can rest in peace :)

back off topic...
I KNOW you recieved it, i have you signiture, you just refuse to accept it, as a result i decided to ignore your scamming words henceforth. YOU are the scammer not me!
The fact of the matter is, you can advise people to not trade with me but i have no intention on, you have put me off, and putting EVERYTHING IN CAPS just makes u look like a pleb. but likewise, i advise nobody to have any dealings with panziandi as your items will magically 'disappear'
p.s. @panziandi- our argument is cluttering up this otherwise clean forum, if you want to hurl more abuse at me then please do, but do it by U2U, i find it amusing

Attachment: My fume hood chemicals compatability.pdf (60kB)
This file has been downloaded 423 times

[Edited on 25-8-2009 by Picric-A]

panziandi - 25-8-2009 at 08:30

To most people who suggest changing the filter less often than the manufacturer suggests, I would tell them not to, because you will find that it likely voids any warranty, and carbon filters will absorb ocmpounds naturally in the atmosphere lowering their activity. However, since it is you, yeah F-it, leave them and change them once every 4 years!

And your signiture supposedly read "Andi" I never sign anything with that name! And when I asked you to present a copy of the receipt with the signiture and the details of the barcode for tracking so I could go to the post office and track it down, you came up with excuses as to why you couldn't. Also a couple of months later when you told me the fume hood would be sent by a courier, you said the bromine would be sent too! Bit suspicious as you had previously claimed it had already been sent to me! you are such a cheating, lying jerk-off! As I said earlier I have had dealings with several people form this site and otehrs, you are the ONLY one i have had issues with because you are a SCAMMER!

Anyway, glad I didn't get this hood, hope your poisoned by a non-replaced spent filter!

Picric-A - 25-8-2009 at 08:35

@ Panziandi- See your U2U

Everybody else- I simply say i will change my filter every 3-4 years because i am rarely in my lab and will rarely be using it. When i am not using it i will seal the filter in a airtight bag.

DJF90 - 25-8-2009 at 08:35

I've traded with panziandi not long ago (2 weeks?) and had NO problems. Maybe you could scan in the postal record for us all to see, I believe the appropriate thread to post it in was created a while back. I doubt he did get the bromine, as he is still looking for some, AFAIK.

And if CleanAir won't reply to your email what makes you think they will sell you the filters...

Picric-A - 25-8-2009 at 08:41

funny that, he told me his friend sent him a litre bottle... so i doubt he is looking for it.
as i told him, i lost the reciept ages ago as it is a small insignificant paper and all this happened months and months ago!

They did reply to my email this morning, hence i have that attachment of compatability. they also sent me prices, servicing prices and offers of specialy made filters so i bet they will sell me filters, i mean whats so restricted about carbon filters?!

btw, what does AFAIK mean?

[Edited on 25-8-2009 by Picric-A]

panziandi - 25-8-2009 at 09:02

FYI (For Your Information) AFAIK stands for: As Far As I Know...

I had to go to a chemical supply house in person and sign for a bottle of bromine a few months back, 250mL. Not a litre!

Oh yes, you "lost it" as soon as I asked for a copy because the (supposed) signiture wasn't mine form the sounds of it! I also have all your MSN and U2Us saved so I can happily compile a pdf of them and post in a thread dedicated to exposing you as a scammer!

DJF90 - 25-8-2009 at 09:03

I didnt mean they could be restricted, I meant they might be funny about selling to an individual.

@panziandi - sounds delightful!

[Edited on 25-8-2009 by DJF90]

NEW U2U from Picric-A

panziandi - 25-8-2009 at 09:07


hahah are you acvtually that retarded?!?!? i said i would buy you another (bringing the total up to £50 i spent on you) bottle of Br2 to send with the hood but then i got bored of you scamming me so i quit. I have the signiture (well i dont know, i lost it but 'fuck it') so i know it was you, you can try get the rest of the forum on ur side but idgas becuase they dont know the proper story and ur not worth the aqrgument, even though it is fucking hilarious as ur going skitz and im calm :) 'Anyway, glad I didn't get this hood, hope your poisoned by a non-replaced spent filter! ' God almight you really have hit an all time low, wishing someones death....

Save on a U2U reply,

Poisoned doesn't necessarily mean death!

I was and still am annoyed because I NEVER received the bromine. If, as you say, there is a signiture, then perhaps the postman signed for it and stole it! What the fuck a postman would want with a bottle of bromine is beyond me however!


stateofhack - 25-8-2009 at 11:31

Uh..Can anyone sell me some Bromine? :P


Saber - 27-8-2009 at 04:36

Hi, most portable (non ducting) fume cupboard have a flter usage meter (at least myn does.)
My fume cupboard says the 18kg charcoal filter will last 3 years OR 2500 hours of use and there is a display showing how many hours it has been used for.
I have also got a Clean Air fume cupboard. they are very well made and filter most gasses (including HCN Picric-A so Panziandis poison threats are void :P)

[Edited on 27-8-2009 by Saber]

panziandi - 27-8-2009 at 05:29

Slightly disappointing news! But I'll live!

DJF90 - 27-8-2009 at 05:29

As will Picric-A...

Saber - 27-8-2009 at 08:14

hahah, by the sound of it he shouldnt but hey! (no offence Picric-A!)

Picric-A - 27-8-2009 at 08:21

Hi saber, myn doesnt have those gauges, this is a picture of myn;
Oh and none taken... :mad:

slide0001_image021.jpg - 16kB

Saber - 27-8-2009 at 08:27

yes that looks like an old model of myn (shown below).

Off topic but i hope to get some pics up of my lab, SO3 plant ect.. on tour my lab shortly, i am currently in the USA however so it will be in a week.

!BW7i34gBGk~$(KGrHgoH-D0EjlLlt1SHBKZ)!IPMzg~~_12.jpg - 21kB

panziandi - 31-8-2009 at 16:12

Funny how Saber and Picric-A have the same spelling mistakes...

Funny how Saber is selling a fume extractor on eBay:

Funny also how the eBay ID is labxyz... funny how it ties in with Picric-A's new ID labxyz on this very site:

Funny how Picric-A and labxyz and Saber are ALL the same person. Really an amazing! Perhaps this site is amatuer bullshite and not amateur science?

DJF90 - 31-8-2009 at 16:23

Well I'll be damned! I guess the contact process plant is made up then :/ My apologies entropy51 :P What is it with you Charlie (aka Picric-A/Saber/Labxyz)! Split personality or something? You should go see a professional about that... Maybe they can give you something for bullshit too

[Edited on 1-9-2009 by DJF90]

Polverone - 31-8-2009 at 16:25

Yes, it looks like Saber is another Picric-A alt.

Klute - 31-8-2009 at 16:59

Some people should definitively grow up.. Incredible how far some go when behind a damn screen.. Ridiculous, really.

Fleaker - 27-6-2010 at 15:45

I wish I knew that saber=picric A. It would have saved me some typing when I repeatedly asked to see his version of the contact process. I was excited to think that some one else had pulled it off and was making oleum. I had oleum available, and merely made that apparatus to prove it is possible to do on the bench. It's disappointing.

Hexavalent - 5-1-2012 at 10:57

I recently got myself a 'Safelab FC750 Recirculating Fume Cabinet' on eBay for just over £250, used. It works very well for small amounts of hazardous chemicals, say, 30-50g or less, but anything more than that I use my enormous directly-ventilated fume hood - aka do it outside.