Are styrene-based products safe?
Few people actually come into physical contact with synthetic styrene in its liquid form as it is a raw material made and used under tightly controlled process and manufacturing conditions similar to other industrial chemicals.
For industrial and manufacturing environments the styrene industry provides comprehensive guidelines for safe handling and personal protection of workers.
Once converted into a plastic or synthetic rubber, the majority of the styrene becomes inert, captured within the material it has been used to produce. Only a small amount of unconverted styrene residue may 鈥榣each鈥� from some styrenic materials over time. Styrene evaporates quickly in the air and degrades rapidly in the environment 鈥� there is no significant bio-accumulation.
Public concern regarding styrene safety therefore relates largely to its use in food and drink packaging, where styrene-based materials come into contact with food and humans.
However, independent scientific tests on styrene migration into food from styrene-based packaging have shown that these very low styrene levels are not linked to health concerns. A 2013 study into styrene-based polymers for food contact use concluded that styrene exposure in the diet attributable to food packaging was significantly lower than the typical dietary concentration - (source: The Safety of Styrene-Based Polymers for Food-Contact Use 2013 Plastics Foodservice Packaging Group, a division of American Chemistry Council).
The United States Food and Drug Administration (FDA) has also determined that polystyrene is safe for use in contact with food.
Regulatory status of styrene
The health effects of styrene continue to generate differences of opinion among regulatory authorities globally.
The European Union (EU) does not classify styrene as a carcinogen. In the US, styrene has been classified by the National Toxicology Program as "reasonably anticipated to be a human carcinogen鈥�, but the American Congress of Governmental Industrial Hygienists determined it is 鈥渘ot classifiable as human carcinogen鈥� and the International Agency for Research on Cancer (IARC) concluded that there is insufficient evidence for carcinogenicity in humans.
The European Chemicals Agency (ECHA) has classified styrene as a Category 2 reproductive toxicant while the US National Toxicology Program determined that there is 鈥渘egligible concern鈥� for adverse developmental and reproductive effects resulting from styrene exposures in humans.
The Styrene Information and Research Center (SIRC) in the US, of which Shell is a member, has funded independent peer reviewed studies including discussions with independent scientists, and believes the current scientific evidence is neither sufficient nor conclusive enough to support the listing of styrene as a possible carcinogen nor a classification for reproductive toxicity.
Through industry associations in the US (SIRC) and the EU (Cefic), Shell supports several studies related to carcinogenicity and reproductive toxicity to provide further clarity.
Styrene - did you know.....
Polystyrene food packaging provides a more hygienic way to keep food fresher, hotter or colder for longer than alternative materials.
