Methanol safety

The use of methanol in consumer products, such as power supplies for portable electronics equipment, raises potential safety problems - as does the use of hydrogen. 

Methanol is a poison, made worse by the fact that it can easily mix with any water-based fluid, such as water supplies or almost any drink. Furthermore, it does not have a taste that makes it immediately repellent, which means it can be drunk. This drinkability problem makes it considerably more dangerous in everyday use than other fuels - such as gasoline - which are also poisonous, and in wide circulation. However, the safety arguments are fairly complex, as methanol is naturally present in the human body, and in small quantities it is perfectly safe. 

Methanol is produced in the body by the action of the digestive system on a wide range of products, particularly natural products such as fruit and also on some man-made additives such as the sweeteners used in diet drinks. It is interesting to note that the body decomposes the methanol, in the liver, to carbon dioxide in exactly the same step-wise fashion as the fuel cell. The steps are methanol to formaldehyde, formaldehyde to formic acid, and formic acid to carbon dioxide. The problem is not the methanol per se, but the formic acid formed in the breakdown process. This acidifies the blood and causes fatal problems if allowed to reach excess levels. 

The main ways of treating patients who have taken methanol is to slow down the initial stages of the process - to keep the methanol as methanol - so that the formic acid concentrations do not become too high. 

An important corollary to this is that methanol is not a cumulative poison in the way of some others such as lead. It does not accumulate in the body. Quite the reverse, the body can deal perfectly well with frequent small exposures - indeed this occurs in nature. It should also be pointed out that methanol is not carcinogenic and has none of the insidious mutagenic properties of some other chemicals. Another important point about methanol safety is that it is much less harmful to the ecology than most other fuels. It quickly breaks down to carbon dioxide in the soil and when exposed to sunlight. It is used as a windshield wash in cars, where all of it is released to the environment, and this poses no hazards. 

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Methanol Safety Methanol is slightly toxic, spreads more easily into the ground than gasoline, and is highly flammable and miscible in water so that contamination with reservoirs is very simple. 

Prepared generally by ester interchange from polyvinylacelate (ethanoate) using methanol and base also formed by hydrolysis of the acetate by NaOH and water. The properties of the poly(vinyl alcohol) depend upon the structure of the original polyvinyl acetate. Forms copolymers. Used as a size in the textile industry, in aqueous adhesives, in the production of polyvinyl acetates (e.g. butynal) for safety glasses. U.S. production 1980... 

The transparency of methanol flames is usually a safety advantage in racing. In the event of fires, drivers have some visibiUty and the lower heat release rate of methanol provides less danger for drivers, pit crews, and spectators. 

In reviewing the fiiU range of health and safety issues associated with all alternative fuels, the California Advisory Board determined that there were no roadblocks that would prevent the near term deployment of either methanol or ethanol, assuming that adequate safety practices were foUowed appropriate to the specific nature of each fuel (14). 

California Energy Commission, Methanol as a MotorEuel Review of the Issues Related to Air Quality, Demand, Supply, Cost, Consumer Acceptance and Health and Safety, Pub. P500-89-002, Sacramento, Calif., April 1989. 

E. R. Panick, L. R. Smith, J. A. Russell and W. E. Likos, "Laboratory Evaluation of Safety-Related Additives for Neat Methanol Euel," SAP Paper 902156, (SP 840), Society of Automotive Engineers, Warrendale, Pa., Oct. 1990. 

P. A. Machiele, "A Perspective on the PlammabiUty, Toxicity, and Environmental Safety Distinctions Between Methanol and Conventional Euels," AIChE 1989 Summer National Meeting (Philadelphia, Pa., Aug. 22, 1989), American Institute of Chemical Engineers. 

Methanol Health and Safety Workshop (Los Angeles, Calif., Nov. 1—2, 1989) South Coast Air QuaHty Management District, El Monte, Calif., 1989. 

P. A. Machiele, "A Health and Safety Assessment of Methanol as an Alternative Puel," ia W. Kohl, ed.. Methanol as an yiltemative Fuel yin yissessment, ]oim. Hopkias Poreiga PoHcy lastitute, Washiagtoa, D.C., 1990, pp. 217—239. 

Methanol is shipped overland by tank cars, tmcks, and dmms. The same safety and materials considerations apply to each of these types of... 

Like brines, alcohols were readily available and widely used as antifreeze Hquids in the early 1900s. Both methanol and ethanol offer exceUent heat transfer and efficient freeze point depression. However, the alcohols have the distinct disadvantage of their low boiling points. During the summer months when the engines operate hot, significant amounts of the alcohols are lost because of evaporation. These evaporative losses result in cosdy make-up requirements. Additionally, the alcohols have very low flash points and potentially flammable vapors. These safety concerns have, particularly in recent years, caused the use of alcohols to be completely discontinued for most heat-transfer systems. 

Formaldehyde has been rated as a possible carcinogen by the United States Occupational Safety and Health Act (OSHA) rules and should be handled with due caution. It is also a strong lacrymator and choking respiratory irritant. It irritates the skin, eyes, and mucous membranes [76]. Since it is used for tanning leather, it is obvious that fonnaldehyde has a high potential for reactions with proteins. Formaldehyde gas is flammable and most formalin solutions contain significant amounts of methanol, which is also volatile, toxic, and flammable. 

Caution Addition of 0 5 cm pieces of sodium metal to methanol or ethanol must be done in a chemical hood and behind a safety shield. Addition should be slow to minimize evaporation loss of methanol or ethanol. No flames or burner should be permitted in the area. Disposal of sodium metal must be earned out in someone s presence. 

Griffin and Albaugh [102] describe a procedure whereby the neutral AOS product is converted to the parent acids by cation exchange and then titrated potentiometrically. A dilute aqueous solution of AOS is passed through cationic ion exchange resin in acid form. The acids are eluted with small portions of water and titrated potentiometrically using tetrabutylammonium hydroxide solution in a solvent mixture of 70 30 benzene/methanol. It is probable that the benzene can be replaced with toluene for safety reasons or that ASTM titration solvent (ASTM D664 toluene/propan-2-ol/water) can be used. 

The electrocatalytic oxidation of methanol has been widely investigated for exploitation in the so-called direct methanol fuel cell (DMFC). The most likely type of DMFC to be commercialized in the near future seems to be the polymer electrolyte membrane DMFC using proton exchange membrane, a special form of low-temperature fuel cell based on PEM technology. In this cell, methanol (a liquid fuel available at low cost, easily handled, stored, and transported) is dissolved in an acid electrolyte and burned directly by air to carbon dioxide. The prominence of the DMFCs with respect to safety, simple device fabrication, and low cost has rendered them promising candidates for applications ranging from portable power sources to secondary cells for prospective electric vehicles. Notwithstanding, DMFCs were... 

Alcohols such as methanol and ethanol are readily available and are occasionally used despite significant disadvantages, such as low boiling points. During summer months significant amounts of alcohol can be lost due to evaporation. Such losses lead to costly replacement of the additive. Furthermore, alcohols have low flash points, which may cause safety problems. Moreover, methanol is highly poisonous. Therefore, the use of alcohols has ceased almost completely in recent years. 

The most critical decision to be made is the choice of the best solvent to facilitate extraction of the drug residue while minimizing interference. A review of available solubility, logP, and pK /pKb data for the marker residue can become an important first step in the selection of the best extraction solvents to try. A selected list of solvents from the literature methods include individual solvents (n-hexane, " dichloromethane, ethyl acetate, acetone, acetonitrile, methanol, and water ) mixtures of solvents (dichloromethane-methanol-acetic acid, isooctane-ethyl acetate, methanol-water, and acetonitrile-water ), and aqueous buffer solutions (phosphate and sodium sulfate ). Hexane is a very nonpolar solvent and could be chosen as an extraction solvent if the analyte is also very nonpolar. For example, Serrano et al used n-hexane to extract the very nonpolar polychlorinated biphenyls (PCBs) from fat, liver, and kidney of whale. One advantage of using n-hexane as an extraction solvent for fat tissue is that the fat itself will be completely dissolved, but this will necessitate an additional cleanup step to remove the substantial fat matrix. The choice of chlorinated hydrocarbons such as methylene chloride, chloroform, and carbon tetrachloride should be avoided owing to safety and environmental concerns with these solvents. Diethyl ether and ethyl acetate are other relatively nonpolar solvents that are appropriate for extraction of nonpolar analytes. Diethyl ether or ethyl acetate may also be combined with hexane (or other hydrocarbon solvent) to create an extraction solvent that has a polarity intermediate between the two solvents. For example, Gerhardt et a/. used a combination of isooctane and ethyl acetate for the extraction of several ionophores from various animal tissues. 

Pyridine and BF3 in methanol are hazardous and must be used only in a well-ventilated hood. A solvent partition after acylation helps remove residual pyridine from the sample. Material Safety Data Sheets for the derivatizing agents should be reviewed and kept readily available. 

Attention is drawn to the hazards involved in the use of perchloric acid in a published method [1] for transesterification of triglycerides with methanol. Alternative acid catalysts and safety precautions are suggested [2],... 

PreservCyt Solution contains methanol, a flammable substance and should be stored in a fire safety cabinet. PreservCyt Solution is stored as follows ... 

Adamson, K.A. and Pearson, P., Hydrogen and methanol A comparison of safety, economics, efficiencies and emissions, /. Power Sourc. 86, 548, 2000. 

Chapter one is an overview of the energy evolution. It introduces the technology and emission issues, safety, and alternative fuels such as natural gas, hydrogen gas, methanol, ethanol and fuel cell power. 

Alternative fuel programs is the theme of Chapter three. Subjects include hydrogen, methanol, syn gas, biofuels, fueling methods, safety and storage. The chapter ends with a discussion of cost issues. 

Methanol, which is also known as wood alcohol, is a colorless and odorless liquid alcohol fuel that can be made from biomass, natural gas, or coal. It is the simplest alcohol chemically and it may be used as an automobile fuel in its pure form (Ml 00), as a gasoline blend of typically 85% methane to 15% unleaded gasoline (M85). It is also used as a feedstock for reformulated gasoline. M100 or pure methanol may be used as a substitute for diesel. In M85, the gasoline is added to color the flame of burning fuel for safety reasons and to improve starting in cold weather. 

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