As the person that said that I would like to try methanol, I
absolutely agree with Margaret and other respondents to the
Denatured Alcohol thread that methanol is poisonous. We should
educate ourselves about all of the toxic chemicals we use around the
studio. However, my preference is to use toxic chemicals when
necessary but to try to limit my exposure to safer levels. I want
to stress a disclaimer here: do not depend on the here
for your own safety…it is written to help you get started thinking
about the subject of toxicology rather than as the last word in the
subject. Read the instructions and be responsible for learning the
properties of what you are working with. With this in mind, I want
to provide a bit of about toxicity in general and about
methanol specifically:
Chronic Exposure & Chronic Effects: Refer to the effects repeated
long term exposure, usually to lower levels of a toxin.
Establishing cause-effect relationships for long term exposure is
difficult because of all of the different factors that can
contribute to the effects being studied. The diseases associated
with tobacco smoking are good examples of chronic effects. I was
not able to find much about the chronic effects of
methanol exposure. Material Safety Data Sheets often fail to
address chronic effects because of the expense and difficulty in
gathering sufficient statistical to eliminate other
enviornmental factors. Liver damage in plastics workers after long
term exposure to vinyl chloride is an example of the successful
study and regulation of a chronic environmental contaminant.
Acute Exposure & Effects: Refer to the effects of a single or short
term exposure where the effects can be observed during, or a short
time after exposure. Blindness or death after exposure to methanol
is an example of an acute effect. The response after a measured
dose of toxin is far easier to determine with studies of acute
effects.
LD50 This refers to the dose at which 50% of the subjects in the
experiment died. Since we don’t experment on humans, LD50
is usually for rats, rabbits, etc. LD50 is expressed in
weight of toxin per unit weight of subject. [Example: LD50 (for
some imaginary toxin) = .01 mg toxin/kg body weight.] Sometimes
after an accident, enough is collected that an LD50 can
be established for humans. LD50 refers to acute exposure, not
chronic exposure.
Irritant: I include this because of an error I made many years ago
that left me sick for several weeks…the label said irritant, I
though “So What?” Irritants can kill you. Example: Chlorine gas
is an irritant. Inhalation will kill you. Ferric chloride is an
irritant…don’t inhale irritant gases or dusts…
I am including some I found on the internet about acute
exposure to methanol. I did not collect the URLs of the sites that
I visitied but used a google search for terms like Methanol Toxicity
etc. Please do not depend on this to expose yourself to
Methanol…do your own research:
Skin Absorbtion rate: 0.192 mg/sq cm/minute (comment…skin
absorbtion rate can vary by a factor of 50 depending on where on the
body it is located. If I remember my college coursework correctly,
you should be more worried about spilling methanol in your lap than
the soles of your feet.) My reaction to a spill (usual disclaimer)
would be to get away from any flame, remove my contaminated clothing
and flush the affected area with water. Contact poision control. I
would not be personally concerned about a small quantity on my
fingers so long as it was rare and washed off immediately.
More on skin…lower doses cause dryness and cracking of skin…the
methanol, like many organic contaminants enters the body by breaking
down the lipids in the skin. Contamination of methanol by other
degreasing agents such as toluene (and I presume acetone) will cause
faster skin absorption. Organic contaminants are typically absorbed
faster on a second exposure than the first because the lipids in the
skin have already been compromised by the first exposure.
Lethal dose (ingested) 30 to 240 ml. (Keep in mind that
susceptablility varies between people depending on body weight and
many other factors. You absolutely don’t want to go for the new
record for sucseptablity.)
Has been observed to cause blindness: (ingested) 15 ml
density: 0.795 g/ml at 19 degrees C.
Permissable exposure limit (PEL, air) 200 ppm (please confirm this
if you use it) I personally would not want to expose myself to levels
anywhere near this limit on a chronic basis. Too little is known
about the chronic effects of this toxin.
Again…this is to get you thinking about doing your own research
into the chemicals you use then making your own decisions as the
whether and how you use them. I can’t stress too much that safe
acute levels are not necessarily safe chronic levels. How we limit
our exposure to chronic levels of toxins is a personal decision we
must all make. Chronic contaminants are all around us everywhere we
go. People tend to accept higher levels of voluntary exposure than
involuntary exposure. Example, most people would accept a higher
risk in their studio than from their drinking water or from air
pollution. Having studied many environmental risks in my
professional career, I am willing to accept small risks to continue
doing the work I love. (I better close this before I get into a
long discussion of risk/cost/benefit relationships). Remember, if
you don’t know what you are doing with chemicals, learn or don’t do
it.
Howard Woods
Eagle Idaho