Methanol (also called methyl alcohol) is the simplest of alcohols. Its chemical structure is CH3OH. It is produced most frequently from wood and wood by­products, which is why it is frequently called wood alcohol. It is a colorless liquid that is quite toxic. The LD50 for oral consumption by a rate is 5628 mg/kg. The LD50 for absorption by the skin of a rabbit is 20 g/kg. The Occupational Safety and Health Administration (OSHA) approved exposure limit is 200 ppm for 10 hours. Methanol has a melting point of -98°C and a boiling point of 65°C. It has a density of 0.791 g/ml and is completely soluble in water, which is one of the hazards of methanol. It easily combines with water to form a solution with minimal smell that still has all of the toxicity issues of methanol. Acute methanol intoxication in humans leads to severe muscle pain and visual degeneration that can lead to blindness. This has been a major issue when considering methanol as a fuel. Dry methanol is also very corrosive to some metal alloys, so care is required to ensure that engines and fuel cells have components that are not corroded by methanol. Today, most research on methanol as a fuel is centered on direct methanol fuel cells (DMFCs) for portable power applications (replace­ments for rechargeable batteries), but extensive early research has been done on methanol-gasoline blends for combustion engines.