The maximum concentration to which workers can be exposed for up to 15 minutes continually. There may be no more than four exposure periods per day, and there must be at least 1 hour between exposure periods. The daily time-weighted-average may not be exceeded, however.
A term used by American Conference of Governmental Industrial Hygienists (ACGIH) to indicate the maximum average concentration allowed for a continuous 15-minute exposure period in the workplace.
ACGIH-recommended exposure limit. Maximum concentration to which workers can be exposed for a short period of time (15 minutes) for only four times throughout the day with at least one hour between exposures.