Definitions for "Threshold limit value"
a time weighted concentration of an air-borne material believed to be safe for nearly all workers occupationally exposed either continuously or repeatedly during an 8-hour day ad 40-hour workweek.
An inhalation time-weighted average exposure level safety limit normally established by the American Conference of Governmental and Industrial Hygienists (ACGIH). Toxicity is characterized in terms of Threshold Limit Values (TLVs) which "represents conditions under which it is believed that nearly all workers can be repeatedly exposed day after day without adverse effects" /ACG90/. For volatile substances, such as refrigerants, TLVs are expressed as parts per million volume concentrations in air (ppm).
The airborne concentration of a substance to which nearly all workers may be exposed without adverse health effects; set by the American Conference of Government Industrial Hygienists (ACGIH). TWA