Let's not get too paranoid about acrylamide
dynamin at hotmail.com
Wed Jul 29 04:08:27 EST 1998
Some late comments and questions on acrylamide (I am not a toxicologist,
but a biochemical-pharmacologist). (My comments are late since I have
been travelling, however this has been one of the best threads for a
How many cases have been reported of acrylamide (monomer) poisoning in
humans? I cannot find the exact number, but the references I have
suggest it is in the thousands.
Who gets acrylamide exposure that LEADS TO a doctor/hospitalisation?
The only reported cases I can find are industry workers, eg those in the
acrylamide manufacturing factory floor in the US, and coal miners (see
eg Am J Ind Med 1996 Jul;30(1):56-61). Both are occupations where staff
are exposed to air-borne or liquid monomer for prolonged periods of
time. I can find no example of a lab worker with acrylamide-induced
neuropathies or other significant problem from medline literature.
Please point them out if you find any.
How much exposure leads to acrylamide-induced clinical problems? I
don't know, but the US "Toxicology Data Management System" at
http://ntp-support.niehs.nih.gov/ refers to specific guidelines for
exposure by inhalation. The details are to be found at
PLEASE READ THIS INFORMATION - IT IS VERY INTERESTING. The conclusion
appears to be that worker absorption of acrylamide be limited to no more
than 0.5 mg/kg per day, and the threshold limit value (TLV) in air be
0.03 mg/m3. The MSDS sheets I have access to mostly quote the same
figure for TLV. My calculations say that a skinny guy (75 kg) in my
lab could breath 35 mg of the stuff every day to reach this limit. I
consider this a hell of a lot to be spilling to the air when weighing
out a hundred grams.
What's all this stuff about acrylamide killing neurons? There is a lot
of medline literature on peripheral neuropathies. However it is
probably fair to say that acrylamide poured onto tissue culture is not
the same as breathing it or spilling it on my skin - it has a long way
to go from there. Also, acrylamide administered to rats at 50 mg/kg
i.p. per day for 5 or 10 days (these doses produce mild and marked
symptoms of neurological damage, respectively, Brain Res 1986 Jan
22;363(2):333-339, Toxicology 1988 Apr;49(1):65-69, J Neurochem 1987
Mar;48(3):924-928) certainly causes reversible peripheral neuropathies
(and central). However that is about the same as my skinny lab worker
colleague injecting or ingesting 3.5 gm every day for a week. What is
the chance of that? Lets say my skinny friend spills 50 ml of 30%
acrylamide solution (15 gm) on his hand. Lets assume 10% of it (1.5 gm)
stays attached for a while. Lets finally assume he decides to wash it
off instead of posting news of his plight to this newsgroup. Just how
much exposure did he really get (0.1 gm??)? What is his real risk? I
don't know, but personally I would wash carefully, change my lab
practices to avoid a repeat episode, then go home to watch television
(exactly what I did in my graduate days). My point is this: acrylamide
monomer is dangerous, but lets not get paranoid.
What web resources are there? Apart from Medline
(http://www4.ncbi.nlm.nih.gov/PubMed/medline.html) I have found the
following acrylamide references to be useful (if not a little repetitive
of their content. I did not recently validate each link):
Has anyone found any others??
Phil Robinson Sydney
(Actually, I've had my PhD for a while now...)
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