On the 22nd of April 22 this year the Office of Environmental Health Hazard Assessment (OEHHA) is adding styrene (CAS No. 100-42-5) to the list of chemicals known to the state to cause cancer for purposes of the Safe Drinking Water and Toxic Enforcement Act of 1986 (Proposition 65). OEHHA has proposed to adopt a No Significant Risk Level (NSRL) of 27 micrograms per day for styrene. The NSRL represents the safe level below which a warning is not required under Prop 65. A warning for exposure to styrene will be required one year from the date it was listed.

Substance Introduction

ChemicalCAS No.Toxicological EndpointListing Mechanism*
Styrene100-42-5cancerAB (NTP)

Listing mechanism: AB – “authoritative bodies” mechanism (Title 27, Cal. Code of Regs. section 25306).

Styrene is used in the following products: coating products, fillers, putties, plasters, modelling clay, polymers and inks and toners. And this substance has an industrial use resulting in manufacture of another substance (use of intermediates) such as plastic products and rubber products.

CA 65 Introduction

Proposition 65, the Safe Drinking Water and Toxic Enforcement Act of 1986 was enacted as a ballot initiative in November 1986. The Proposition was intended by its authors to protect Californian citizens and the State’s drinking water sources from chemicals known to cause cancer, birth defects or other reproductive problems and to inform citizens about exposures to such chemicals. All products containing hazardous substances within the scope of its control, including but not limited to Electrical and electronic products, textiles, toys, food contact materials, jewellery,  and home decor products.

Proposition 65 requires the state to maintain and update a list of chemicals known to the state to cause cancer or reproductive toxicity. The latest California 65 control list is as below.

Further Information

Notice – Styrene Listed as Known to the State of California to Cause Cancer.

Proposition 65 List Dated April 22, 2016

CTI Suggestion

California„s 65 does not set limit to the material. The limit of substances in the products should refer to the existing lawsuit aiming at this kind of product or agreement. Enterprise should compare the existing lawsuit of substances control requirements and focus on newly added substances and risky chemicals. In order to reduce the risk of illegal, companies are suggested to conduct supply chain survey and perform test if necessary.