Dr. Spencer Reid:  Methanol is compositionally speaking , the simplest of the alcohols . It 's actually ubiquitous in the environment . There are small traces of its vapor in the atmosphere , but atmospheric methanol is easily oxidized by sunlight .
Emily Prentiss: Is it toxic ?
Dr. Spencer Reid: Ingesting ten milliliters of it will cause permanent blindness , and as little as _ 30 _ is potentially fatal .
Derek Morgan: Well , these victims had between five and six ounces in their lungs .
Dr. Spencer Reid: You know , if they were immersed in it , they would have died even without ingesting or inhaling it . When absorbed through the skin , it depresses the central nervous system to an unsustainable degree .
Derek Morgan: Well , what 's it used for ?
Dr. Spencer Reid: What is n't it used for ? A solvent , an antifreeze . In World War II , the Germans used it for rocket fuel . It 's used in wine - making . Its most commonplace use however , is in the creation of other chemicals . Methanol can become plastic , plywood , paint , explosives , permanent - press textiles . It 's essentially the chemical used to separate other chemicals from each other .