EPA Identifies Worker Exposure Risks for 1,3-Butadiene in Industrial Settings

The U.S. Environmental Protection Agency (EPA) has completed a risk evaluation of 1,3-butadiene, identifying potential unreasonable health risks for workers exposed to the chemical through inhalation in certain industrial environments.

According to the agency, the evaluation identified risks in 11 industrial settings where 1,3-butadiene is manufactured or used to produce materials such as rubber, plastics, and other chemical products. One of the conditions contributing to the risk determination involved the use of the substance as an intermediate reactant in industrial processes, including applications related to adhesive manufacturing and synthetic rubber production.

EPA reported that exposure risks are associated primarily with workplace environments where workers may encounter higher concentrations of the gas. The agency indicated that personal protective equipment commonly used in industrial facilities can help mitigate these risks.

The agency did not identify unreasonable risks to consumers, the general population, or nearby communities from the uses evaluated. Consumer products typically contain very small amounts of 1,3-butadiene, according to EPA.

Under the Toxic Substances Control Act (TSCA), the agency will now begin developing risk management rules intended to address the identified worker exposures. EPA stated that the rulemaking process will consider health impacts, exposure levels, economic factors, and benefits of the chemical’s use while engaging with industry stakeholders.

The agency also reported improvements to its evaluation methodology compared with earlier drafts. EPA incorporated facility-specific emissions data from the National Emissions Inventory (NEI), which includes information such as stack height, emission temperature, and release angles. According to EPA, this data allows for more precise modeling of emissions and exposure conditions.

In addition, EPA incorporated peer-review recommendations to combine cancer risk estimates associated with bladder cancer and leukemia, which increased the overall cancer risk estimate used in the final evaluation.

1,3-butadiene is widely used in the production of materials found in products such as tires, coatings, adhesives, and automotive care products.

Source: EPA / Adhesives & Sealants Magazine