The US Environmental Protection Agency (EPA) has concluded that the rubber ingredient 1,3-butadiene, which it classifies as a human carcinogen, might present health risks to industrial workers but poses no threat to the environment or those living near facilities where the chemical is used. The conclusions, announced on New Years Eve, contrast with regulations put in place during Joe Biden’s presidency that required companies to monitor levels of the chemical in the air outside their plants.
Based on what the EPA describes as a ‘robust review’ of 1,3-butadiene that incorporated the results of approximately 10,000 studies from various sources, the agency said it has found ‘potential unreasonable health risks’ to workers who may inhale the chemical in 11 specific industrial settings at factories that make or use 1,3-butadiene to create rubber, plastics, and other products. The World Health Organization’s International Agency for Research on Cancer also categorises the chemical as ‘carcinogenic to humans’.
The EPA said its findings indicate the use of personal protective equipment (PPE) in these workplace environments will help mitigate health dangers associated with 1,3- butadiene. However, the agency also concluded that there is no evidence the chemical poses unreasonable risks to the environment or the general population, including people living near facilities that use the chemical. The latter conclusion contrasts with the EPA’s previous clean air standards for chemical plants that were finalised in April 2024.
‘EPA’s analysis, which examined impacts from facility releases on surrounding communities within 0.3 to 31 miles, did not find unreasonable risks to the environment, for consumers, or to the general population including people living near facilities,’ the agency said in a statement to Chemistry World.
The Biden-era regulations, which aimed to reduce harmful emissions by nearly 80%, set targets for six pollutants, including 1,3-butadiene. The rule included a requirement for these facilities to monitor fencelines for chemicals like 1,3-butadiene, and mandated that the EPA make such data publicly available to better inform and safeguard nearby communities.
However, under leadership of attorney-turned-politician Lee Zeldin, installed by the Trump administration in January 2025, the EPA has begun formally reconsidering dozens of environmental regulations – including the clean air standards for chemical plants put in place by Biden in 2024. The agency describes this effort as the ‘biggest deregulatory action in US history’.
Plastic additives
The agency also announced on 31 December that it will regulate dozens of applications of five widely used phthalates to address environmental and workplace risks linked to these chemicals. The agency said this decision was based on final risk evaluations for each of these chemicals, which include butyl benzyl phthalate, dibutyl phthalate, dicyclohexyl phthalate, diethylhexyl phthalate and diisobutyl phthalate. These are commonly used in the manufacture of flexible plastics and, the agency notes, are endocrine disruptors with the potential to cause hormone deficiencies.
Next, the EPA plans to develop rules to eliminate the identified unreasonable risks that phthalates pose to worker safety and the environment. The agency says it will carry out ‘extensive consultation’ with workers, businesses, labour groups, and communities to ‘develop targeted, practical protections’ that ensure worker safety and environmental protection. In addition, the agency says that it will to ‘carefully’ evaluate to PPE, engineering controls, and alternative approaches to protect those populations most at risk from phthalates.
No comments yet