Hazardous Materials Identification System. The Hazardous Materials Identification System (HMIS) is a numerical hazard rating that incorporates the use of labels with color developed by the American Coatings Association as a compliance aid for the OSHA Hazard Communication Standard. 1 HMIS Color Bar.
Definition of greenhouse gas. : any of various gaseous compounds (such as carbon dioxide) that absorb infrared radiation, trap heat in the atmosphere, and contribute to the greenhouse effect.
Full Definition of NATURAL GAS. 1. : gas issuing from the earth's crust through natural openings or bored wells; especially: a combustible mixture of methane and other hydrocarbons used chiefly as a fuel and raw material. 2.