Toxicity

Refers to the physiological effect of absorbing a poisonous substance into the system, either through the skin, through mucous membranes or into respiratory system. When describing their toxic effect, solvents are usually classified as having high, medium, or low toxicity, depending upon whether a solvent vapor concentration of less than 100, 100 to 400 or over 500 parts per million respectively is the maximum amount permissible in the air for safe or healthful working conditions.