Skip to main content
Welcome to the cutting edge of safety science—Learn more about our rebrand.
  • Feature Story

OEHHA Adopts Reference Exposure Levels for Caprolactam

December 18, 2013

The Office of Environmental Health Hazard Assessment (OEHHA) of California has adopted the Reference Exposure Levels on the use of caprolactam.

Caprolactam is the monomer used in the polymerization process to manufacture synthetic fibers and resins, known as Nylon-6 Exposure to caprolactam has been found to cause upper respiratory and eye irritation in both animals and humans.

The exposure levels developed on the use of caprolactam are:

  • Acute REL (for a 1-hour exposure): 50 micrograms per cubic metre (μg/m3) or (11 ppb);
  • 8-hour REL (for repeated 8-hour exposures): 7 μg/m3 (1.4 ppb); and
  • Chronic REL (for long-term exposures): 2.2 μg/m3 (0.5 ppb).