The European Food Safety Authority (EFSA) has published a long-awaited re-assessment of the potential genotoxicity of styrene used in plastic food contact materials, concluding that the substance does not raise safety concerns when migration into food is limited to 40 micrograms per kilogram.
The new scientific opinion, released in response to a request by the European Commission, evaluated whether styrene poses a genotoxic risk when ingested through contact with plastic packaging. The assessment followed years of uncertainty, beginning with a 2018 classification by the International Agency for Research on Cancer (IARC) which labelled styrene as “probably carcinogenic to humans.” That classification led the European Commission to ask EFSA to re-evaluate the evidence and consider the safety of a proposed specific migration limit (SML) of 40 parts per billion (ppb), equivalent to 40 µg/kg of food.
EFSA’s latest review incorporated a broad range of data, including in vivo genotoxicity studies in rodents, toxicokinetic analyses, and human exposure data. These were drawn from scientific literature published since 2018, submissions from the US-based Styrenic Information and Research Center (SIRC), and the IARC’s 2019 monograph.
Using a weight of evidence approach, EFSA concluded there was no indication of genotoxicity from oral exposure in animal studies. Moreover, the toxicokinetic data suggested humans are less susceptible to the effects of styrene than rodents. According to EFSA guidance, substances shown not to be genotoxic are unlikely to pose a safety concern at migration levels up to 50 µg/kg. Given that the proposed SML for styrene is lower—set at 40 µg/kg—EFSA stated that such use “is not considered a safety concern.”
The findings are likely to offer regulatory clarity and reassurance to manufacturers using styrenic materials in packaging production. Styrene is commonly used in polystyrene and other plastic polymers for food packaging applications, making EFSA’s conclusion critical to the continuity of existing manufacturing practices.
This latest opinion also addresses the data gaps and uncertainties previously identified by EFSA in 2020. At that time, the authority had called for more comprehensive evaluations of both experimental and human data. With this re-assessment, EFSA affirms that its concerns have been resolved, noting that no additional relevant uncertainties were identified.
The European Commission is expected to move forward with the formal adoption of the 40 ppb SML as part of forthcoming regulations on food contact materials.
