Sciencemadness Discussion Board - HEXAVALENT CHROMIUM

HEXAVALENT CHROMIUM

azo - 3-12-2011 at 03:41

Just near me orica has an ammonium nitrate plant which just recently had a major leak of hexavalent chromium and was forced to do i big clean up of entire towns.We were told by them and the government that there was no great danger to people which i find hard to swallow.Since then they also had a major ammonia leak and has now been shut down by the government.But the government is likely to allow the reopening of the plant due to the fact that the mining industry is now running out of explosives.
And at the moment there is a mining boom like you would not believe.Could anyone tell me or no more about this compound and its dangers,it appears to me that this is a very reactive and dangerous compound.

shame orica :mad:

regards azo

DJF90 - 3-12-2011 at 05:17

Cr(VI) is generally considered carcinogenic (group IB IIRC) by inhalation, but otherwise is fine to work with in the lab with care. Obviously the danger is proportional to the quantity released and in what form; chromyl chloride (volatile liquid) is obviously more of a danger than say chromic anhydride (CrO3) or a chromate/dichromate salt.

[Edited on 3-12-2011 by DJF90]

Sedit - 3-12-2011 at 08:28

I'm one to be a fear monger but it honestly does not sound to good for the area around.

Quote:

Although the exact scenario behind the mishap was a matter for official inquiries, Mr Newman said that hot water, rather than steam, had been fed into the catalyst, resulting in a ‘‘rain’’ of water-soluble hexavalent chromium coming from the stack in question.

As much as 10kilograms of dissolved hexavalent chromium is believed to have escaped the stack.

The chromium leak took place on Monday, August 8, and was followed by an illegal discharge of arsenic into the Hunter River on Friday, August 19.

I personally would not want it to rain any form of Cr(IV) on me especially when its a water soluble form. The water table in the area is more then likely in bad shape and I would get your water tested periodically in the future just to be safe.

10kg may not be much but as I understand it Cr(IV) isn't exactly a lightweight when it comes to causing cancer so there may be some need for concern.

The arsenic does not really help much either.

[Edited on 3-12-2011 by Sedit]

AndersHoveland - 3-12-2011 at 14:00

There was also a much publicized incident in California involving hexavalent chromium contamination
http://en.wikipedia.org/wiki/Hinkley_groundwater_contaminati...

hkparker - 3-12-2011 at 15:02

I know Davis, CA is also known for hexavalent chromium contamination. Apparently it is created from chromium 3 compounds and "organic waste".

http://www.news.ucdavis.edu/search/news_detail.lasso?id=9392

ScienceSquirrel - 3-12-2011 at 16:02

There are a lot of questions about any chromium VI release.
How much and what was it released are first questions.
Chromium VI released in to alkaline organic rich waters will rapidly be turned in to chromium IIi species and precipitated out of solution.
Acid water with little in the way of native oxidising agents might carry the chromium VI for miles through the ground water.

AndersHoveland - 3-12-2011 at 16:03

heptavalent manganese can also be toxic

ScienceSquirrel - 3-12-2011 at 18:35

Quote: Originally posted by AndersHoveland

heptavalent manganese can also be toxic

It can be, but it quickly finds reducing agents in the environment that turns it in to manganese IV or III.

AJKOER - 13-12-2011 at 14:46

Remember that bathing in water is also a means to exposure.

I believe I read that Ascorbic acid (Vitamin C) can help reduce the Cr to less dangerous forms.

California has set a target level exposure to Hexavalent Chromium in water to .02 parts per billion.

gutter_ca - 14-12-2011 at 11:54

Quote: Originally posted by AJKOER

Remember that bathing in water is also a means to exposure.

I believe I read that Ascorbic acid (Vitamin C) can help reduce the Cr to less dangerous forms.

California has set a target level exposure to Hexavalent Chromium in water to .02 parts per billion.

Ugh, yes they have. And I can barely see 0.2ppb on my IC-UV/VIS. Serious PITA.

mr.crow - 14-12-2011 at 12:47

Callifornia is full of bullshit laws. Apparently these signs are on everything and everywhere. What a joke

I think the problem comes from being reduced to Cr(III) inside of cells. Oxidants are also bad in general, so thats where the anti-oxidant craze comes from

Sucks about the leak, stay safe

[Edited on 14-12-2011 by mr.crow]

Hexavalent - 3-3-2012 at 15:51

Dearie me, Mr Crow. . .I never knew it was that bad. Personally, I have just acquired 500g of pure potassium dichromate. I have read MSDSs but they seem to be unclear from this perspective; when handling <3 gram quantities, is this sufficient - heavy latex gloves, lab coat, disposable respirator/dust mask, goggles and working outside? Thanks

Bot0nist - 3-3-2012 at 16:07

Quote: Originally posted by mr.crow

Callifornia is full of bullshit laws. Apparently these signs are on everything and everywhere. What a joke

I think the problem comes from being reduced to Cr(III) inside of cells. Oxidants are also bad in general, so thats where the anti-oxidant craze comes from

Sucks about the leak, stay safe

[Edited on 14-12-2011 by mr.crow]

Acrylamide! If acrylamide posed a significant threat to human health, then we would not exist. So if we all cut out all food that were not boiled, steamed, or raw we would achieve what? A year or two added to the average lifespan? At what cost. Seeing that sign as I bite into a delicious scone or enjoy an espresso would cause me an amount of malaise far greater than the ingested acrylamide.

I'm going to go eat some really crusty french bread with salted butter and basil right now.

[Edited on 4-3-2012 by Bot0nist]

ScienceSquirrel - 3-3-2012 at 16:29

Think about it in terms of your overall exposure to toxins and carcinogens.
In the morning you may use a petrol powered lawn mower or saw. so you have the exposure to the fuel when filling it and also the exhaust.
You fire up the barbecue. There are all sorts coming from the burning of the charcoal and the cooking of the food.
You walk past your neighbour's garden and smell the smoke from his bonfire, a bus goes past and you catch a whiff of diesel fumes.
Finally you have a couple of cigarettes with your beer before returning home.
I would not slop potassium dichromate around but as long as you deal with it on a small scale it is pretty safe.
Compared with potassium cyanide it is pretty safe.
I did undergraduate experiments with it on the open bench and thirty years later I am still here.
When I started my small brewery I had some arguments with Environmental Health about nitrates in the water. I had 40 - 50 mg/l and they were worried about that. After some research I found that hops are full of nitrate so beer can be as much as 150mg/l.
This is low in nitrate compared with spinach, preserved meat, etc so they withdrew their objections.
Sadly too many of these MSDS are being written by people who do not seem to have any understanding of reasonable limits or environmental exposure.

borrowedlawyer - 3-10-2012 at 05:52

I just bought some ammomium dichromate not realising how toxic it actually is, i just read some sources that sate it as extremely, extremely toxic. Is there any way to safely handle it (is gloves, respirator, face shield, work area covered in foil sufficient) or should i leave it alone? Or am I being stupid?

Thanks

ScienceSquirrel - 3-10-2012 at 06:21

Just use it in small quantities.
Do not spill it on your hands or the bench, snort it like cocaine or swallow it and you will be fine.

borrowedlawyer - 6-12-2012 at 20:37

Thanks Mr. Squirrel for the reply.

Regarding the first post of this thread, I also live around this area.

What really enrages me is this, 'Orica failed to notify government authorities until 16 hours after the incident and residents were not formally notified for three days.'

One year on from the +6 Chromium leak: http://www.abc.net.au/news/2012-08-08/one-year-on-from-toxic...

It amazes me the things they have leaked last year and this year and it is still not shut down; +6 chromium, arsenic, ammonia, mercury, ammonium nitrate, sulfuric acid, cyanide, ANOTHER mercury leak and finally their hydrogen stack ignited.

It is obvious that their facility is dangerous and is not contained correctly, yet they are allowed to continue to operate.

They are finally being taken to court: http://www.news.com.au/breaking-news/national/orica-denies-n...

[Edited on 7-12-2012 by borrowedlawyer]

IrC - 6-12-2012 at 23:32

Quote: Originally posted by azo

Just near me orica has an ammonium nitrate plant which just recently had a major leak of hexavalent chromium and was forced to do i big clean up of entire towns.We were told by them and the government that there was no great danger to people which i find hard to swallow.Since then they also had a major ammonia leak and has now been shut down by the government.But the government is likely to allow the reopening of the plant due to the fact that the mining industry is now running out of explosives.
And at the moment there is a mining boom like you would not believe.Could anyone tell me or no more about this compound and its dangers,it appears to me that this is a very reactive and dangerous compound.

shame orica :mad:

regards azo

A very easy and entertaining way to see how Chrome 6 can mess you up is just watch the movie 'Erin Brockovich'.

mycotheologist - 11-12-2012 at 09:34

Did they not say what particular hexavalent Cr compounds were leaked?

S.C. Wack - 11-12-2012 at 12:38

Quote: Originally posted by IrC

A very easy and entertaining way to see how Chrome 6 can mess you up is just watch the movie 'Erin Brockovich'.

Yep, it's a great illustration of just how easily some nobody from out of town, with little expertise in anything, can fool a court into massive liability judgements against you, with (even now many years later) no evidence of causing anyone any bodily harm.

smaerd - 11-12-2012 at 12:48

I have a nice little tub of sodium dichomate but I haven't used it yet because I'm not sure how I could do safe disposal? Any hints or ideas?

ScienceHideout - 11-12-2012 at 13:43

Quote: Originally posted by smaerd

I have a nice little tub of sodium dichomate but I haven't used it yet because I'm not sure how I could do safe disposal? Any hints or ideas?

I know that in the USA, the city I live in offers hazardous waste meets every so often. You basically drive your car to a parking lot specified on the website, and unload it, giving leftover paints, thermostats, batteries, you name it, to workers.

Usually I get a couple funny looks when I give them milk jugs full of mercury, nickel, chromium, and other various solutions... but they are happy to take it knowing that I didn't pour it down the drain

borrowedlawyer - 11-12-2012 at 14:10

Quote: Originally posted by mycotheologist

Did they not say what particular hexavalent Cr compounds were leaked?

It was sodium chromate.

borrowedlawyer - 11-12-2012 at 14:12

Quote: Originally posted by smaerd

I have a nice little tub of sodium dichomate but I haven't used it yet because I'm not sure how I could do safe disposal? Any hints or ideas?

Why get rid of it, its not that bad if handled in lab conditions. Gloves, goggles, lab coat, outside and maybe a disposable respirator.

smaerd - 11-12-2012 at 14:13

I just mean post-reaction, not that I want to toss it out, rather the waste from using it. Thanks for the advice though I'll have to look into that.

[Edited on 11-12-2012 by smaerd]

DJF90 - 11-12-2012 at 16:41

sodium metabisulfate solution completely reduces it to Cr(III). Precipitation as the (hydrous) oxide allows you to recover the chromium in a usable form.

borrowedlawyer - 11-12-2012 at 18:29

Quote: Originally posted by smaerd

I just mean post-reaction, not that I want to toss it out, rather the waste from using it. Thanks for the advice though I'll have to look into that.

[Edited on 11-12-2012 by smaerd]

Oh, just pour it into sodium thiosulfate solution and wash glass used with it out with it