skin contact with acrylamide

Bryan L. Ford fordb at bcc.orst.edu
Mon Jul 20 18:10:16 EST 1998


Dima Klenchin wrote:

> > > The rest
> > > does not penetrate the skin that fast - a brief wash should suffice.
 
Ford wrote:

> > This is erroneous advice. Acrylamide monomer is a small, amphipathic,
> > molecule with considerable ability to dissolve in polar and non-polar
> > substances (that is in plasma and to pass cell membranes. Acrylamide
> > monomer has high mobility through normal latex lab gloves as well.
> > Immediate and extended washing with water should be strongly advised.
> > Immediate further treatment might have been beneficial but any delays
> > increase the likelihood of permanent and progressive damage.

 
Peter wrote:

> Acrylamde can only travel through the skin if you have it dissolved in a
> carrier capable of passing through the skin.  I have always seen the
> monomer disolved in aqueous solutions therefore it will not travel through
> the skin. 

Ford replies:

Such an argument, presumably rooted in thinking about partition
coefficients, is not correct even if acrylamide were a large and
non-amphipathic molecule. Acrylamide itself can partition into the skin
and widely distribute in tissues and into cellular compartments. The
aqueous solution is perhaps less dangerous than other conceivable
solutions with higher dermal transport rates, but even this is not
proven. 

Peter wrote:

> The danger with acrylamide in the Lab is the weighing out
> stage.  It can be breathed in and thus cause great damage. 

Ford replies:

Agreed that this is the greatest danger.

Peter wrote:

> In solution on
> your skin, it is not capable of causing great harm.  It is reactive enough
> that it will not travel far in the plasma. 

Ford replies:

We are discussing the free monomer, are we not? (Once polymerization is
underway in solution the danger from aqueous dermal absorption begins to
drop progressively with time since the concentration of monomer
declines, at a variable but often rapid rate.) Absorbed free monomer,
the component of a typical gel mix that is most likely to be absorbed,
is not particularly reactive in plasma. The distribution rate constants
exceed those for reaction/metabolism considerably. 

Peter wrote:

> The primary target of aqueous
> contact with acrilamide is the corss-linking of sensory neurons.  They
> will regenerate over time.

Ford replies:

There is not "cross-linking of sensory neurons". I presume you mean
cross-linking within sensory neurons. The damaging effects of such
crosslinking result in defective axoplasmic transport within such
neurons. As a note to other readers: these lesions have nothing to do
with the catalytic agents that are in the typical gel prep-- the monomer
alone provokes the neuropathology, the crosslinking reagents (if they
were to be absorbed) have entirely distinct, and also potentially
dangerous toxicology. The degeneration of sensory neurons is generally
not reversible although some recovery from the milder effects of shorter
term exposure has been reported. 

Dima Klenchin wrote:

> > > Next, to
> > > get long-term effects of acrylamide poisoning, one must have really strong
> > > short-term effects, which isn't something you describe.

Ford wrote:

> > This is almost diametrically contrary to fact. Long-term effects of
> > acrylamide neurotoxicity from moderate occupational exposures are very
> > frequently not accompanied by any short-term effects. However, short-
> > term effects are reported and have severe prognostic indications.

Peter wrote: 

> YOU ARE NOT TALKING ABOUT ACRILAMIDE THAT IS IN SOLUTION. 

Ford replies:

I am talking about acrylamide that is in solution. The effects of
inhalation are even more serious and we can discuss those if you like.

> What you are
> looking at is the long term effects of Breathing of the monomer powder.
> It is very very nasty. 

A good thing to look at, but not what I was looking at.

Peter wrote:

> When I weigh out the powder I Have a mask(.2um
> pores) and no one enters the lab til I am finished(no air currents).  

Ford replies:

I agree completely with this particular assertion.  The solid powder is
extremely dangerous. The pulmonary absorption rate is far higher than
the already dangerous dermal rate, hence even greater danger. Also the
specific concentrations that pulmonary tissues near a dissolving
fragment of the solid monomer may experience have their own specific
toxicological hazards, including possible carcinogenicity or
co-carcinogenicity. However, once a given amount enters the plasma the
distribution is similar regardless of entry portal. Contrary to the
assertion made by Peter, the unpolymerized monomer does not rapidly
react in plasma, but instead rapidly distributes across many
physiological compartments. The vulnerability of long neurons of sensory
tracts has to do with their extremely long axoplasmic flow requirements,
and possibly their relatively low cytoplasmic turnover rates. The
latency to observable sensory decrements is well-documented and the poor
reversibility is also well documented. I recommend that lab workers
avoid the use of powdered acrylamide as much as possible. Instead, I'd
suggest using the available acrylamide/bisacrylamide e.g. 19:1 40%
premixes, since there is much lower likelihood of inhalating these. But
again one needs to be aware of, and limit dermal exposures.

Peter writes:

> You nead to learn to read.

Ford replies:

You apparently "nead" to learn this and more. 
 
-Bryan



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