Methyl alcohol toxicity

Metabolic differences also account for the great species variability in methyl alcohol toxicity with humans and nonhuman primates being uniquely sensitive. (A relatively poor ability to metabolize the methanol-metabolized formate in these species leads to increased blood formate levels and subsequent metabolic acidosis and neuronal toxicity.)... 

The concentration of a solute has a considerable effect on the viscosity of the fluid and so on the surface convective resistance to heat flow. There is little published data on these effects, so applications need to be checked from basic principles. Industrial alcohol (comprising ethyl alcohol with a statutory addition of methyl alcohol to render it poisonous) may be used as a secondary refrigerant, either at 100% concentration or mixed with water. The fluid has a low viscosity and good heat transfer, but is nowlittle used on account of its toxicity and the fire risk in high concentrations. Other nonfreeze heat transfer fluids are used in specialist trades. 

The main drawback to this reaction is the toxicity of diazomethane and some of its precursors. Diazomethane is also potentially explosive. Trimethylsilyldia-zomethane is an alternative reagent,42 which is safer and frequently used in preparation of methyl esters from carboxylic acids.43 Trimethylsilyldiazomethane also O-methylates alcohols.44 The latter reactions occur in the presence of fluoroboric acid in dichloromethane. 

However, if you link the hydroxyl group with the methane molecule rather than the ethane, you get the potentially toxic chemical called methyl alcohol, or wood spirit. Similarly, if you add what s called an aldehyde group (-CHO) instead of the hydroxyl group, you will get one of a variety of chemicals called aldehydes, of which a common one is the gas formaldehyde (HCHO), widely used in the manufacture of plastics and glues. This gas can be an irritant and potentially dangerous if inhaled. 

Methyl alcohol (methanol and toxic Optic nerve... 

Alcohols. Methyl alcohol, and to a lesser extent ethyl alcohol, were used as freezing point depressants for many years. Their use now is minimal. When properly inhibited, alcohol-water solutions can be satisfactory coolants only under restricted conditions. Alcohol antifreezes fell into disuse because of their low boiling point (lower than that of water) and the danger of loss from boiling or evaporation. Alcohol volatilizes from hot surfaces much more readily than glycol coolant and can be a potential fire hazard. Methyl alcohol liquids are both flammable and poisonous. Methyl alcohol vapors are toxic when inhaled at high concentrations. 

Methanol or methyl alcohol can become an alcoholic s main source of alcohol because it is cheaper. Methanol is frequently used as an additive for industrial ethanol to circumvent taxes. Methanol may be purposely adulterated to make it less palatable, but it is used nevertheless Methanol ingestion can be fatal due to its CNS depressant effects. In addition it is toxic because it is a substrate for alcohol dehydrogenase forming formic acid and formaldehyde which... 

Antifreeze agents are also used in fuels where severe environmental conditions are encountered. For example, a mixture of methyl alcohol, isopropyl alcohol, TM Dry-gas, and sometimes proprietary substances are used to inhibit the formation of ice from water vapor in hydrocarbon fuels. It is added directly to the gasoline. These additives are toxic and flammable. 

Methyl alcohol possesses distinct natcotic properties. It is also a slight irritant to ihe mucous membranes. The principal toxic effect is exerted on the nervous system, particularly the optic nerves and possibly Ihe relinae. The eflect upon the eyes has been attributed to optic neuritis, which subsides, but is followed by atrophy uf the optic nerve. Once absorbed, methyl alcohol is only very slowly eliminated. Coma resulting from massive exposures may last as long as 2 to 4 days. In the body, the paiducis formed hy its oxidation arc formaldehyde and formic acid, both of which are toxic. 

Denatured (or Industrial) Alcohol (Denatured Spirits). Colorless liquid (which is sometimes artificially colored blue or red to distinguish it from ordinary alcohol) consisting of ethyl alcohol and "denaturants . Its toxicity depends on de-naturants used, of which the principal one is methyl alcohol. This ale produces blindness. 

ETHYL ALCOHOL C2H5OH also called grain alcohol or ethanol. This is the only type of alcohol that is safe to drink. Other alcohols like methyl alcohol and isopropyl alcohol are highly toxic and poisonous. 

Toxic solvents, such as methyl alcohol, benzene, and chlorinated hydrocarbons, can penetrate the skin through cuts and abrasions. On contact, these solvents cause chronic dermatitis and allergic skin reactions in susceptible individuals. 

When a painting is finished, the artist often applies varnish or lacquer to the painting surface. Varnishes, and often paints, are thinned with turpentine. Turpentine can be used to remove surface varnish. Turpentine is moderately toxic if inhaled or ingested. Carbon tetrachloride, toluene, and methyl alcohol are also used to remove varnish (see Figure 10.2). Carbon tetrachloride and toluene are highly toxic if routinely inhaled. 

Methyl alcohol (CH3OH) Demos 1.2. 10.1 Toxic in high doses or chronic exposure. Avoid skin and eye contact. Never ingest. 

The artist, with the help of a sound knowledge of chemistry, can substitute less-toxic materials for highly toxic substances. For example, methyl alcohol, toluene, or methylene chloride can be substituted for benzene, which is used as a paint and varnish remover, and boric acid can be substituted for phenol, which is used as a preservative. The chemist needs the artist to shed new light and for a new point of view so that the chemist can develop appropriate and better art materials. 

Nature produces a tremendous amount of methyl alcohol, simply by the fermentation of wood, grass, and other materials made to some degree of cellulose. In fact, methyl alcohol is known as wood alcohol, along with names such as wood spirits and methanol (its proper name the proper names of all alcohols end in -ol). Methyl alcohol is a colorless liquid with a characteristic alcohol odor. It has a flash point of 54°F, and is highly toxic. It has too many commercial uses to list here, but among them are as a denaturant for ethyl alcohol (the addition of the toxic chemical methyl alcohol to ethyl alcohol in order to form denatured alcohol), antifreezes, gasoline additives, and solvents. No further substitution of hydroxyl radicals is performed on methyl alcohol. 

Methanol (methyl alcohol) was originally produced by the destructive distillation of wood chips in the absence of air. This source led to the name wood alcohol. During Prohibition (1919-1933), when the manufacture of alcoholic beverages was prohibited in the United States, anything called alcohol was often used for mixing drinks. Since methanol is more toxic than ethanol, this practice resulted in many cases of blindness and death. 

Toxicity and health effects Exposure to vapor of methyl alcohol causes irritation to the mucous membranes. Toxic effects are exerted upon the nervous system, particularly the optic nerve. Once absorbed into the body, it is very slowly eliminated. Symptoms of overexposure include but are not limited to headache, drowsiness, nausea, vomiting, blurred vision, blindness, drunkenness, insomnia, abdominal pains, coma, and death. Oral ingestion of large amounts of methyl alcohol has caused nausea, giddiness, and loss of consciousness in humans. ... 

Some pesticides are sufficiently soluble in water to permit their formulation in water. However, this may not be done unless hydrolytic stability and toxicity hazard are favorable. Instead, such compounds are dissolved in a water-miscible solvent to avoid hydrolysis and then mixed with water before application. Examples of such formulations are Azodrin WMC (formulated in hexylene glycol) and Lannate WMC (formulated in dimethyl formamide and methyl alcohol). 

The ethylene glycol and methyl alcohol (see below), which is also sometimes found in antifreeze, are poisonous because they are converted into more toxic products. Once inside the body, the ethylene glycol in the antifreeze is changed by metabolism into first one, and then several other chemicals. This requires the same enzyme that metabolizes the alcohol we consume in alcoholic drinks (ethyl alcohol). The ethylene glycol is converted into oxalic acid which is poisonous, and other poisonous products are also produced. Oxalic acid is also found in rhubarb leaves, which is what makes them poisonous. The result of these metabolic conversions is that the acidity of the blood increases (the pH decreases) and normal metabolic processes are inhibited. The oxalic acid formed can crystallize in the brain and the kidneys, causing damage. The oxalic acid also reacts with calcium and removes it from the body. The reduction of calcium... 

Although methylated spirits, or meths , is a mixture of ethyl alcohol (the alcohol we normally drink in beer, wine, and spirits) and methyl alcohol, it is not normally a serious hazard in terms of accidental poisoning. This is because the presence of the ethyl alcohol acts as an antidote it reduces the conversion of the methyl alcohol into the toxic substances that would otherwise cause poisoning. However, the regular use of meths as a substitute for alcohol, for example by down and outs and alcohohcs, wiU lead to serious damage. 

There have been cases of poisoning as a result of the alcohol used in laboratories being added to punch for parties. This is usually not pure alcohol but industrial methylated spirits and may contain a significant amount of methyl alcohol (4 per cent). As the lethal dose of methyl alcohol is about 70 ml, it is unlikely this could be achieved in the short space of time during a party, but drinking a strong punch made in this way would certainly lead to unpleasant toxic effects such as headache, nausea and vomiting, and blurred vision. 

One chemical that we take for granted and do not usually consider to be hazardous is the alcohol found in aU alcohohc drinks. While this alcohol, known as ethyl alcohol or ethanol to chemists, is much less toxic than methyl alcohol, it is both a drug and a potential poison. Indeed, alcohol is classified as a human carcinogen, that is, capable of causing cancer, by the International Agency for Research on Cancer (lARC) because there is evidence that excessive intake increases the incidence of cancer, for example in the oesophagus. 

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