NIOSH Study & Best Practices

In May of 2022, the National Institutes of Occupational Safety and Health (NIOSH) released its exposure study for sealcoat applicators. NIOSH is part of the U.S. Department of Health and Human Services, Centers for Disease Control and  Prevention and until now, exposure assessment research for RCTS (refined coal tar sealants) workers has not been published. The study was conducted over a period of six year and includes 32 pages of highly technical information, including input from PCTC. (To access the full article, you must pay $40 or access it via the PCTC website)

As many of us already know, coal tar sealers have been used in the United States since the mid-twentieth century, yet this represents the first published study of worker exposure to known carcinogens.  In addition, and perhaps most importantly, the study provides the coatings and sealant community with an additional opportunity to reinforce the use of best practices in the field.

The objective of the study was to “develop a representative occupational exposure assessment of PAH exposure for RCTS workers based on worksite surveys.”  A total of twenty-one workers on crews from three separate companies using coal tar sealers were studied. They used a variety of protections (or none) from Tyvek to wearing the same clothes during the week. They studied skin exposure, air concentrations of coal tar-related chemicals and typical coal tar derived chemicals in the urine of the workers. Urine was tested before a shift started and after. 

These are typical methods used by researchers looking at chemical exposure because chemicals from coal tar sealers (polycyclic aromatic hydrocarbons or PAHs) enter the body through the skin, breathing or eating and many are excreted in urine.[1]

While the study referenced the fact that PPE was not worn by all study participants, we found the most significant statement within the study to be one that  is “These results indicate the need to increase safety controls and exposure mitigation for RCTS (refined coal tar sealer) workers.”

Because of this, please reference our best practice for PPE documents below.

Best Management Practices for Sealcoating

Best Management Practices Website Card

Best Management Practices Graphic

[1] Coal Tar Fee America