List of highly toxic gases


Many gases have toxic properties, which are often assessed using the LC50 measure. In the United States, many of these gases have been assigned an NFPA 704 health rating of 4 or 3, and/or exposure limits determined by the ACGIH professional association. Some, but by no means all, toxic gases are detectable by odor, which can serve as a warning. Among the best known toxic gases are carbon monoxide, chlorine, nitrogen dioxide and phosgene.

Definition