Close this search box.

Hazardous Exposures During the Carr Fire Cleanup: A Health Hazard Evaluation Summary

The Carr Fire was the sixth most destructive wildfire in California history, burning 229,651 acres and destroying 1,079 residences, 22 commercial buildings and 503 outbuildings before it was fully contained on August 30, 2018. Hazardous materials left behind in the fire debris should be removed in a safe manner to protect cleanup workers, the general public and the environment before rebuilding can occur. Debris cleanup is typically done by construction crews consisting of operators and laborers.

What are these hazardous materials and why are they harmful?

What Is the HHE program?

The National Institute for Occupational Safety and Health (NIOSH) HHE Program helps employees, union officials and employers learn whether health hazards are present at their workplace and recommends ways to reduce hazards and prevent work-related illness. NIOSH is part of the Centers for Disease Control and Prevention (CDC). Once an HHE request is received, a multidisciplinary team of NIOSH specialists conducts the evaluation. The findings and recommendations are released in an HHE report posted to the NIOSH HHE website.

Hazardous materials found in fire debris may include respirable crystalline silica (RCS, a component of cement), asbestos used in insulation, metals from products such as home electronics and polyaromatic hydrocarbons (PAH) found in soot. RCS and asbestos exposures may lead to chronic respiratory diseases and lung cancer. Metals such as lead, beryllium and cadmium can damage many organ systems and some have been associated with the development of cancer. Lead exposure may also lead to high blood pressure and kidney problems in adults and permanent neurological damage in children if brought into the home. Most of the 18 PAHs in soot are suspected or known to cause cancer.

Why was an evaluation of the fire debris cleanup work done?

In March 2018, representatives from the California state agency that oversees wildfire debris cleanup, the International Union of Operating Engineers and the construction company that supervised the Carr Fire cleanup jointly requested a Health Hazard Evaluation (HHE) due to concerns about exposures to RCS, asbestos, metals and PAHs among fire debris cleanup crews. Representatives from area LIUNA Local Unions were also engaged in the HHE process.

What did NIOSH experts do during this evaluation, and what were the results?

NIOSH teams conducted the on-site evaluation in September 2018 during the Carr fire cleanup. This evaluation included observations of work practices, measurement of workers’ exposures to RCS, asbestos, metals and PAHs in the air, measurement of metals and PAHs on workers’ skin and interviews with workers about their work practices and health.


A NIOSH industrial hygienist collects a hand wipe sample from a worker. 

Seventeen laborers and operators participated in air and skin sampling, while 40 workers (laborers, operators and site supervisors) participated in confidential medical interviews. The air sampling results showed that some skid steer operators were overexposed to RCS. Laborers and excavator operators were not overexposed to RCS. None of the workers were overexposed to asbestos, metals or PAHs in the air. NIOSH found metals, including lead and PAHs, on the hands and necks of some workers. None of the interviewed workers reported medical conditions or symptoms they thought were work-related.

What else did the NIOSH team observe?

One of the main methods to reduce workers’ exposure to contaminated dust is by spraying water on debris as it is moved to prevent dust from getting into the air, where workers can inhale it. We observed that water sprays were not consistently applied, resulting in visible dust clouds around workers in a lot footprint. Personal protective equipment (PPE) was not always worn, and when it was worn, it was not always worn correctly. PPE included nitrile gloves, respirators and hearing protection (earplugs or ear muffs). The NIOSH team also noticed that workers were not always using hearing protection. This could potentially lead to hearing damage if sound levels from heavy equipment or other sources were elevated.


A laborer uses a water spray for dust suppression while an operator clears large debris pieces.

Based on their test results and observations, what did NIOSH recommend?

First, NIOSH recommended that workers learn about the risks of RCS exposure. Because the lung damage from RCS cannot be reversed, workers should know the risks and how to properly wear respirators to protect themselves. Water sprays for dust suppression should be consistently used when working in the lot footprint.

Second, workers should wash their hands and use lead-removal wipes whenever they leave the lot footprint and before they eat, drink or smoke. To keep their families safe, workers should also change their shoes before going home to avoid exposing those at home to these contaminants.

Third, PPE should be used consistently and correctly. Workers should receive training on the correct use of respirators, nitrile gloves and earplugs. Contractors should ensure employees are medically cleared to wear the designated type of respirator, receive training on how to correctly wear and store the respirator, etc. as per Cal/OSHA’s  respirator protection standard. Workers should use nitrile gloves instead of latex gloves due to the risk of developing a latex allergy from repeated exposure. Lastly, workers’ noise exposure should be measured. If noise exposure exceeds the Occupational Safety and Health Administration threshold of 85 dBA over an eight-hour shift, a hearing conservation program should be implemented to help prevent permanent hearing loss.

Please see the full HHE report, Evaluation of Fire Debris Cleanup Workers’ Exposure to Silica, Asbestos, Metals and Polyaromatic Hydrocarbons, for additional details.

[C. Beaucham and J. Eisenberg, NIOSH Division of Field Studies; C. Hamilton, NIOSH Division of Science Integration. For questions, contact Judith Eisenberg at]

Recent Lifelines