[Jewelry making - Article 00484] - [Orchid] Methanol & Toxicity

[FrodoGem]

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    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 information 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 information 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 information 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 information 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
    information 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 information 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 information 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 information 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

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