Exposure Monitoring

To protect their employees, employers must monitor their workplaces and work operations to accurately determine the concentrations of airborne benzene to which workers may be exposed.

There are a number of methods available for monitoring employee exposures to benzene. The employer has the obligation of selecting a monitoring method that meets the accuracy and precision requirements of the standard under the employer's unique field conditions. One common method is sampling and analysis by collection of the benzene vapor on charcoal absorption tubes, with subsequent chemical analysis by gas chromatography. Other sampling and analysis methods include portable direct reading instruments, real-time continuous monitoring systems, and passive dosimeters.

Whatever method is used, the monitoring for concentrations of airborne benzene is required to be accurate to a confidence level of 95 percent to within plus or minus 25 percent.

To learn more about Benzene Safety visit our Cal/OSHA Benzene Safety Online Training web page.