Medicine. Narcosis is a state of deep stupor or unconsciousness produced by a chemical substance such as a drug or anesthesia. A narcotic is a substance that induces narcosis. Additional Info: Inhalation of certain chemicals can lead to narcosis. For example, diethyl ether and chloroform, two common organic solvents, were among the first examples of anesthesia known. Deliberate inhalation of chemicals such as spray paints and household aerosols to obtain a quick "buzz" or high, a practice called huffing, is an disturbingly common activity among adolescents and young adults. This practice is exceedingly dangerous and likely to lead to brain damage or death. See: The inhalants links under Further Reading for more information. Many other chemicals that you would not suspect can also cause narcosis. For example, even though nitrogen gas comprises 78% of the air we breatheand is considered chemically inert (unreactive) it can cause narcosis under certain conditions. MSDS Relevance: This term usually appears on an MSDS as a possible symptom of exposure, usually through inhalation. Always work with adequate ventilation and avoid inhaling chemical fumes, mists, dusts etc. whenever possible. Use fume hoods and respirators as necessary. See also: Anesthesia, Coma, Ventilation