Hunton Employment & Labor Perspectives

As California braces for wildfire season, the California Division of Occupational Safety and Health (“CalOSHA”) approved an emergency regulation on July 30, 2019, that requires California employers to monitor air quality for particle pollution, and reduce workers exposure to the potential harmful pollutants from wildfire smoke.

What Is Particle Pollution or Particle Matter?

The Air Quality Index (“AQI”) is calculated for four major air pollutants regulated by the Clean Air Act: ground level ozone, particle pollution, carbon monoxide and sulfur dioxide. The new regulation is aimed at protecting workers from certain particle pollution, also called particulate matter or PM. There are two types of PM – fine particles (2.5 micrometers or less in diameter, referred to as PM2.5) and course particles (particles between 2.5 and 10 micrometers in diameter, referred to as PM10). The new regulation is directed only at the fine particles, or PM2.5, which are produced from all types of combustion, including wildfires.