Health Hazard Evaluation Report 2010-0156-3196 Summary Page 1

Evaluation of Dermal Exposure to Polycyclic 

Aromatic Hydrocarbons in Fire Fighters 

Report No. 2010-0156-3196 Summary

December 2013

Kenneth W. Fent, PhD, CIH

Judith Eisenberg, MD, MS

Doug Evans, PhD 

Deborah Sammons

Shirley Robertson

Cindy Striley, PhD

John Snawder, PhD

Charles Mueller, MS

Vance Kochenderfer

Joachim Pleil, PhD

Matthew Stiegel, PhD

Gavin P. Horn, PhD

U.S. Department of Health and Human Services

Centers for Disease Control and Prevention

National Institute for Occupational Safety and Health
Page 2 Health Hazard Evaluation Report 2010-0156-3196 Summary

Contents

Introduction......................................... 1

Methods ............................................... 1

Results and Discussion........................ 1

Conclusions.......................................... 2

Recommendations............................... 3

The cover photo is a close-up image of sorbent tubes, which are used by the HHE 

Program to measure airborne exposures. This photo is an artistic representation that may 

not be related to this Health Hazard Evaluation. Photo by NIOSH.
Health Hazard Evaluation Report 2010-0156-3196 Summary Page 1

Introduction

The Health Hazard Evaluation Program of the National Institute for Occupational Safety 

and Health (NIOSH) carried out a study of fire fighters’ exposure to polycyclic aromatic 

hydrocarbons (PAHs) and other aromatic hydrocarbons during controlled structure burns. We 

wanted to know if these chemicals, which are produced during fires, pass through the skin 

and enter the fire fighters’ bodies. Some PAHs and other aromatic hydrocarbons are known or 

suspected of causing cancer.

Methods

The study consisted of two rounds. In each round, five fire fighters fought a controlled 

structure burn once a day for 3 days. Fire fighters wore new or freshly laundered turnout gear 

each day and wore self-contained breathing apparatus (SCBA). 

The burns took place in a timber-framed structure or a metal container; interior walls were 

covered with drywall. The rooms were set up with typical family room furniture. The burns 

lasted an average of 22 minutes. Fire fighters’ activities included an average of 11 minutes 

watching the fire build, 3.5 minutes knocking down the fire, and 7.5 minutes doing overhaul. 

We collected air, breath, urine, and wipe samples of the skin (forearms, hands, neck, face, 

and scrotum) throughout the day. We analyzed the samples for the following:

● Levels of PAHs and aromatic hydrocarbons in the air during fire fighting

● Levels of PAHs on fire fighters’ skin before and after firefighting 

● Levels of PAHs and aromatic hydrocarbons in fire fighters’ blood and urine before and 

after fire fighting

Results and Discussion

PAHs and Aromatic Hydrocarbons in Air 

All the burns released PAHs into the air. The PAH levels in air during the burns were the 

same or higher than levels reported in other fire fighting studies. The levels of PAHs in air 

during active fires were higher than the occupational exposure limit for five of the burns. The 

air levels decreased after knockdown. However, for two burns, the air levels remained above 

the occupational exposure limit during overhaul. This is an important finding because fire 

fighters do not always wear SCBA during overhaul.

The equipment we used to measure aromatic hydrocarbons in air before knockdown only 

worked properly for one burn. During this burn, benzene was the main aromatic hydrocarbon 

in air, and was present at levels nearly 30 times the occupational exposure limit. The 

equipment we used to measure aromatic hydrocarbons in air after knockdown (during 

overhaul) worked properly for three burns. During these three burns, benzene, styrene, and 

toluene were the main aromatic hydrocarbons in air. They were present at levels well below 

occupational exposure limits.
Page 2 Health Hazard Evaluation Report 2010-0156-3196 Summary

PAHs on Skin 

The PAH levels on fire fighters’ necks were higher just after fire fighting than just before. 

This finding suggests that the PAHs came from the fires. Fire fighters’ necks were protected 

only by a Nomex® hood made of a double layer of porous fabric. Also, the hoods used in 

round 1 were shorter than those used in round 2, and some came untucked during firefighting. 

In general, we detected no PAHs on other areas of fire fighters’ skin. The scrotum, forearms, 

and hands were protected by turnout gear or gloves made of multiple layers of protective 

fabric, and the face was protected by positive-pressure SCBA facemasks. 

PAHs in Fire Fighters’ Bodies

Levels of PAHs excreted in urine 3 hours after fire fighting were higher than those excreted 

just before or just after firefighting. However, the levels of PAHs in urine were similar to 

those found in workers with low levels of workplace exposures to PAHs. These findings 

suggest PAHs entered the fire fighters’ bodies through their skin. 

Aromatic Hydrocarbons in Fire Fighters’ Bodies

Benzene was the main aromatic hydrocarbon we measured in fire fighters’ breath. Levels 

of benzene in breath were higher just after fire fighting than just before. Other aromatic 

hydrocarbons (toluene, xylene, and styrene) also followed this trend. These findings suggest 

that aromatic hydrocarbons in air entered fire fighters’ bodies through their skin. Because we 

detected no benzene in urine after fire fighting, it appears that the amount of benzene entering 

the fire fighters’ bodies was low.

Other Findings 

We tested the SCBA during round 2 on a breathing machine to make sure they were working 

properly. All but one SCBA passed the test. We found that turnout gear used during fire 

fighting became contaminated and released chemicals such as benzene into the air 25 minutes 

or more after fire fighting. Levels of the contaminants released from turnout gear were well 

below occupational exposure limits.

Conclusions

Benzene and some of the PAHs released during the controlled burns entered the fire fighters’ 

bodies. Because fire fighters wore SCBA, the PAHs and benzene most likely entered through 

skin on the neck, which was the least protected area on the fire fighters’ bodies. Benzene 

released from contaminated turnout gear may have been inhaled when fire fighters removed 

their gear after fire fighting. The levels of PAHs and benzene in fire fighters’ bodies were 

similar to those in other groups of workers with low levels of workplace exposures to the same 

chemicals. Thus, turnout gear appears to protect skin against PAHs and aromatic hydrocarbons.
Health Hazard Evaluation Report 2010-0156-3196 Summary Page 3

Recommendations

On the basis of our findings, we recommend the following actions to further reduce exposure 

to PAHs and aromatic hydrocarbons during firefighting.

● To minimize breathing contaminants:

○ Maintain and test SCBA routinely to ensure its proper function.

○ Wear SCBA during overhaul.

○ Remain upwind of the fire if not directly involved in the response.

○ Provide as much natural ventilation as feasible to burned structures before starting 

investigations and when responders are not wearing respiratory protection.

● To minimize skin absorption of contaminants:

○ Wear long hoods that are unlikely to come untucked during operations.

○ Keep protective ensembles on during overhaul.

○ Wash hands immediately and shower as soon as possible after a fire response.

○ Put on laundered station uniforms after showering.

○ Launder turnout gear routinely using a professional service.

● To minimize inhalation of chemicals that are released from contaminated gear:

○ Remove SCBA (and hood) last when doffing gear.

○ Doff gear before entering the rehab area.

○ Store gear on the outside of the apparatus during the ride back to the station.
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Health Hazard Evaluation Report 2010-0156-3196 Summary Page 5

The Health Hazard Evaluation Program investigates possible health hazards in the workplace under the 

authority of the Occupational Safety and Health Act of 1970 (29 U.S.C. § 669(a)(6)). The Health Hazard 

Evaluation Program also provides, upon request, technical assistance to federal, state, and local agencies 

to investigate occupational health hazards and to prevent occupational disease or injury. Regulations 

guiding the Program can be found in Title 42, Code of Federal Regulations, Part 85; Requests for Health 

Hazard Evaluations (42 CFR Part 85).

Disclaimer

The recommendations in this report are made on the basis of the findings at the workplace 

evaluated and may not be applicable to other workplaces.

Mention of any company or product in this report does not constitute endorsement by the National 

Institute for Occupational Safety and Health (NIOSH).

Citations to Web sites external to NIOSH do not constitute NIOSH endorsement of the sponsoring 

organizations or their programs or products. NIOSH is not responsible for the content of these Web 

sites. All Web addresses referenced in this document were accessible as of the publication date.

Acknowledgments 

Analytical Support: Ardith Grote, Jennifer Roberts, Bureau Veritas North America, and NMS Labs

Desktop Publishers: Mary Winfree 

Editor: Ellen Galloway 

Health Communicator: Stefanie Brown 

Industrial Hygiene Field Assistance: Matthew Dahm, Gregory Burr, James Couch, Robert 

McCleery, and Donald Booher

Logistics: Donnie Booher and Karl Feldmann

Respirator Inspection Support: Charles Wolfe

Availability of Report

Copies of this report have been sent to the employer, employees, and union at the call center. The state and 

local health department and the Occupational Safety and Health Administration Regional Office have also 

received a copy. This report is not copyrighted and may be freely reproduced. 

This report is available at http://www.cdc.gov/niosh/hhe/reports/pdfs/2010-0156-3196.pdf.

Recommended citation for this report:

NIOSH [2013]. Health hazard evaluation report: evaluation of dermal exposure to polycyclic 

aromatic hydrocarbons in fire fighters. By Fent KW, Eisenberg J, Evans D, Sammons D, 

Robertson S, Striley C, Snawder J, Mueller C, Kochenderfer V, Pleil J*, Stiegel M*, Horn G†. 

Cincinnati, OH: U.S. Department of Health and Human Services, Centers for Disease Control 

and Prevention, National Institute for Occupational Safety and Health, NIOSH HETA Report 

No. 2010-0156-3196.

*U.S. Environmental Protection Agency, Human Exposure and Atmospheric Sciences 

Division

†University of Illinois-Urbana/Champaign, Illinois Fire Service Institute
Delivering on the Nation’s promise:

Safety and health at work for all people through research and prevention

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