Published exposure level
Published exposure level means the exposure limits published in NIOSH Recommendations for Occupational Health Standards dated 1986, which is incorporated by reference as specified in 1910.6 or if none is specified, the exposure limits published in the standards specified by the American Conference of Governmental Industrial Hygienists in their publication Threshold Limit Values and Biological Exposure Indices for 1987-88 dated 1987, which is incorporated by reference as specified in 1910.6.