I said that??
anyway..
how about some real information about methanol....?
from Methanex
Methanol is a clear biodegradable liquid usually made from natural gas.
It is a petrochemical that is used to make countless industrial and
consumer products such as synthetic textiles, recyclable plastics,
household paints and adhesives, foam cushions and pillows, and even
common medicines such as ASA (acetylsalicylic acid).
Methanol is used to manufacture a fuel component that when added to
gasoline makes the gas burn more cleanly and produce fewer emissions.
Methanol is also used to remove nitrates from municipal waste water.
Regardless of the exposure route, methanol distributes readily and
uniformly to all organs in
direct relation to their water content (Yant and Schrenk, 1937).
Interestingly enough, drinking an
aspartame sweetened beverage (like a diet soda) has the potential to
increase the methanol body
burden as aspartame is hydrolyzed in the intestinal mucosa to 10%
methanol by weight (Statoil,
1999).
Methanol’s fate in the human body is well understood. Methanol is
neither mutagenic nor
carcinogenic and the metabolism of methanol and the mechanisms of
toxicity are issues that
have been studied extensively.
Once methanol is absorbed it is rapidly distributed in the body water
with peak blood levels occurring in about 30 to 90 minutes after
exposure. If ethanol is not present 2-5% of the methanol is excreted
unchanged by the kidneys and a small amount is eliminated by the lungs.
At low blood levels the half-life of methanol is 2-3 hours. Once the
blood levels rise above 300 mg/dl, the enzymes that metabolize methanol
become saturated and the elimination half-life increases to 27 hours.
When this happens a greater amount of the methanol is eliminated
unchanged by the lungs and the kidneys. During therapy with ethanol the
half-life of methanol becomes 30-52 hours.
Methanol itself may cause inebriation but by itself in almost completely
non-toxic. The methanol is metabolized by alcohol dehydrogenase to
formaldehyde and then to formic acid. Clinical findings correlate better
with formic acid levels than with methanol levels. It is these two
metabolites that cause toxicity with formic acid being more responsible.
It is the formic acid that causes the profound metabolic acidosis that
is typical of methanol poisoning. The overall mortality of methanol
poisoning is approximately 20% and among survivors the rate of permanent
visual impairment is 20-25%.
*
*The presentation within the first 1-2 hours may be similar to ethanol
intoxication in that the patient may have drowsiness, vertigo, and
uninhibited behavior. There is typically a delay of the toxic symptoms
anywhere from six-30 hours and longer if ethanol has been co-ingested.
In cases of methanol ingestion a lack of symptoms early on does not mean
that the patient has not ingested a toxic amount of methanol.
There are several treatments available to combat the effects of methanol
toxicity, for example
Sodium Bicarbonate
Early treatment with sodium bicarbonate is essential to compensate
metabolic acidosis –
here the sodium bicarbonate is used to bring the blood to a normal
physiological pH to help
prevent or reverse visual impairment.
Hemodialysis
In severe cases, hemodialysis is considered to be an effective treatment
for removing both
methanol and formate from the blood.
Ethanol Treatment
The metabolism of methanol is inhibited by the co-exposure to ethanol.
Ethanol acts as a
competing substrate for the alcohol dehydrogenase enzyme and as a result
clinically
administered ethanol treatments have been shown to prevent the elevation
of formate levels.
Methanol exposure...
Exposure/Dose Added body burden Reference
of methanol (mg)
Background in a 70 kg body 35** Kavet & Nauss 1990
Hand in liquid methanol, 2 min 170 IPCS 1994
Inhalation, 40 ppm methanol for 8 hr 170 IPCS 1994
Inhalation, 150 ppm for 15 min 42 Kavet & Nauss 1990
0.8 litre diet beverage 42 Kavet & Nauss 1990
Ingestion of 0.2 ml of methanol 170
Ingestion, 25-90 ml Lethal (20,000 – 71,000 mg) IPCS 1997
**estimated from 0.73 mg/l in blood
thats interesting.... drinking a diet soda will probbly give you more
methanol in your system than taking a good wiff in your wash barrel...
Ray J
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