CFR 117C - 1,3-Butadiene

On November 4, 1996, federal OSHA promulgated a final rule to amend its existing regulations for employee exposure to 1,3-Butadiene, (61 FR 214, 56746-56856). The amended rule is applicable to all employment in general industry, construction, and shipyards. The North Carolina Administrative Code at 13 NCAC 07F.0101 currently contains an 8-hour TWA (Time Waited Average) limit of 1000 ppm. The new federal standard contains an 8-hour TWA  limit of 1 ppm, and a short term exposure limit (STEL) of 5 ppm for 15 minutes.

In addition, the new federal standard includes an "action level" of 0.5 ppm, measured as an 8-hour TWA, as a mechanism for exempting an employer from some administrative burdens in instances where the employer can demonstrate that the employee's exposures are consistently at very low levels. The new federal standard also contains provisions for engineering controls, work practices and personal protective equipment, measurement of employee exposures, training, medical surveillance, hazard communication, regulated areas, emergency procedures and record keeping. The final federal rule became effective February 3, 1997. 

This final rule concerning employee exposure to 1,3-Butadiene was adopted verbatim in North Carolina by the Commissioner of Labor with an effective date of March 7, 1997.