Lowered Occupational Lead Exposure Limit Challenges California Companies

Lowered Occupational Lead Exposure Limit Challenges California Companies

By Sarah Kalika, PG, CAC, CDPH Lead Inspector/Assessor/Supervisor 

On January 1, 2025, California’s lowered occupational limit for lead content within a worker’s breathing zone went into effect. The occupational limit for lead has two parts: Permissible Exposure Limit (PEL) based on the maximum exposure allowed during an 8-hour workday, and the Action Level (AL) which is the threshold of exposure above which additional precautionary measures should be implemented to prevent exceeding the PEL. California Division of Occupational Safety and Health, commonly referred to as Cal/OSHA has set the PEL for lead at 10 µg/m3 and the Action Level at 2 µg/m3, significantly lower than the Federal OSHA limits.

The United States Occupational Safety and Health Administration (OSHA), which covers workers across the US in construction trades, general industry, and specialty industries such as ship workers, established a PEL in 1978 for lead of 50 µg/m3 and an Action Level of 10 µg/m3. California’s lowered limit has caused some companies to consider, sometimes for the first time ever, how to ensure their worker exposures do not exceed the AL and/or PEL.

Exceeding the Action Level is of considerable concern, as exceeding 2 µg/m3 in California requires, among other items:

• Lead awareness training (2 hours minimum, annually)
• Health evaluation by an Occupational Health doctor / fitness to wear a respirator
• Respiratory protection of a minimum of 1/2 face respirator equipped with P-100 HEPA cartridges (if PEL is exceeded)
• Additional worker exposure air monitoring
• Record keeping of medical data, testing results, and training participation for 40 years
• Blood lead level testing

How do we quantify exposure?
To determine compliance with the occupational lead exposure limit, employers need to perform exposure air monitoring at least annually to quantify employee exposure and compare to the AL and PEL. Air samples are collected over a workday of at least 7 hours by continuously capturing air within the worker’s breathing zone. A calibrated low-flow battery powered vacuum pump is equipped with tubing and a specialty cartridge specific for collection of airborne lead samples and placed within the breathing zone of the worker. This sampling apparatus accompanies workers throughout their day, collecting tiny air particles, bits of dust, and anything else sucked into the cartridge. Accredited laboratory analysis is required to determine the quantity of lead within the air that employees were exposed to during their workday.

For some companies, California’s lowered threshold has caused concern, while many others remain unaware of the new requirement. For geotechnical and environmental consultants in California, as well as general remediation contractors, grading contractors, and others who excavate soil in areas impacted by lead, the new Action Level has prompted employers to consider worker lead exposures on many more projects.

How much lead in soil results in an Action Level exceedance?
Using a conservative calculation that assumes that the contaminant, in this case lead, is present within visible dust particles in a proportional quantity to the concentration of the contaminant in soil at a project site (using the PEL for general nuisance dust of 5 µg/m3), we have determined that a concentration of at least 400 mg/kg of lead within soil can cause exposure at the Action Level if exposure to visible dust occurs. (Figure 1)
Geologists and other field personnel, particularly those who work in the environmental assessment and remediation industry, are routinely on sites with lead concentrations that exceed 400 mg/kg, so this new Cal-OSHA PEL requires employers to perform testing and provide additional mitigations, including enhanced dust control measures or respiratory protection, to ensure worker safety in more situations. Using the calculation in Figure 1, a worker may exceed the California PEL (or Federal Action Level) of 10 µg/m3 if soil concentration is 2,000 mg/kg or higher and the worker is exposed to visible dust.

Prevalence of lead and health impacts

Lead is prevalent in the dust and soil of many residential, commercial, agricultural, and industrial locations including alongside roadways that have been in use for longer than 30 years. Among other uses, lead was added to paints and coatings until the late 1970’s, as a gasoline additive until the mid-1990’s which resulted in leaded tailpipe emissions and aerially deposited lead alongside roadways, and until the official ban in 1988 within lead arsenate pesticides sprayed around buildings and in orchards. Additionally, water erosion of leaded paint applied to exterior building components can cause an accumulation of lead in shallow soil beneath roof runoff driplines. Lead dust often is found the vicinity of lead paint abatement projects and structure demolitions, particularly if dust control measures are not used. Exposures to lead can cause elevated blood lead levels which are linked to health conditions including brain damage, kidney disease, and cardiovascular illness. In people with a calcium deficiency, lead can replace calcium in bone marrow which results in lead released gradually into the bloodstream.

In addition to this lowered PEL, California’s new standard reduced the allowable blood lead level (BLL) from 40 micrograms per deciliter (µg/dL) to 10 µg/dL, which is the threshold that workers must be temporarily removed from a job causing lead exposures. This sample is collected by an occupational safety medical clinic. Many workers in this situation are temporarily moved to office jobs, within a warehouse, or other task that that does not involve lead exposure. The body processes lead from the bloodstream by distributing it to the brain and soft tissues and excess lead is excreted over time. Workers under temporary removal orders must allow the lead in their blood to fall below 10 µg/dL before being allowed to perform their previous tasks. This may take several days to weeks.

Information leads to better protection
By lowering the occupational limit for lead, California hopes to reduce worker exposure and increase use of dust control methods, resulting in increased protection for workers exposed to lead as part of their employment. For workers to benefit from this reduced exposure, companies must be aware of the new threshold for compliance.

Sarah Kalika, PG, CAC is a California Department of Public Health certified Lead Inspector / Assessor and Supervisor with over 24 years of experience as an environmental consultant in California. She is the Immediate Past President of AEG and Principal Geologist at DiabloGeo Environmental Consulting.

References:

Agency for Toxic Substances and Disease Registry, accessed 2025. Lead Toxicity https://archive.cdc.gov/www_atsdr_cdc_gov/csem/leadtoxicity/biologic_fate.html
California Department of Occupational Safety and Health, 2025. Title 8 CCR, Section 5198. Lead. https://www.dir.ca.gov/title8/5198.html
National Library of Medicine, 2012. Potential Health Risks to DOD Firing-Range Personnel from Recurrent Lead Exposure. https://www.ncbi.nlm.nih.gov/books/NBK206974/
Occupational Safety and Health Administration. Lead. https://www.osha.gov/lead#:~:text=Employers%20are%20required%20to%20protect,Standards%20section%20of%20this%20webpage
Occupational Safety and Health Administration, General Industry Standard, 29 CFR 1910,
Subpart Z, Standard 1910.1025-Lead. https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.1025
Occupational Safety and Health Administration, Construction Industry Standard, 29 CFR 1926.62-Lead. https://www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.62