Lead Levels

The amount of lead present in the air is expressed as a measurement of how many micrograms of lead are in one cubic meter of air. For instance, the Cal/OSHA Permissible Exposure Limit (PEL) is 50 micrograms of lead per cubic meter of air (50 µg/m³). This number is averaged over an eight-hour workday. If an employee works more than eight hours in a day, his or her permissible exposure limit, in micrograms of lead per cubic meter of air, is 400 divided by the hours worked in the day.

The Cal/OSHA action level for lead exposure is 30 micrograms per cubic meter of air, which is not dangerous in itself, but is high enough to trigger some of the safety measures, such as exposure monitoring, medical surveillance, and training.

Human exposure to lead is typically measured by looking at a person's blood lead level (BLL). Blood lead levels are measured in micrograms of lead per deciliter of blood, which is written as µg/dl. The goal of the Cal/OSHA lead standard is to keep a worker's blood lead level below 40 micrograms of lead per deciliter of blood. Once the level rises above 40 micrograms of lead per deciliter of blood, the risk of disease increases. The level at which certain illnesses develop is different for everyone.

To learn more about Construction Lead Exposure visit our Cal/OSHA Construction Lead Exposure Online Training web page.