The California Office of Environmental Health Hazard Assessment (OEHHA) has published the preliminary agenda for its Carcinogen Identification Committee’s (CIC) meeting on Bisphenol A (BPA) for December 14, 2022. The meeting will consider the evidence regarding carcinogenicity of BPA and decide whether to add the chemical to Proposition 65.
- The Office of Environmental Health Hazard Assessment (OEHHA) is California’s state agency for health risks posed by environmental contaminants. OEHHA’s primary duty is to implement the Safe Drinking Water and Toxic Enforcement Act of 1986, also known as Proposition 65, which in part tracks a list of substances that the state has found to cause cancer or reproductive harm. OEHHA also works with California’s Departments of Public Health and Toxic Substances Control (CDPH and DTSC) on administering the Biomonitoring California which focuses on the levels of chemicals in California residents’ blood.
- Proposition 65 requires businesses to provide adequate warnings to California residents for “significant exposures” to chemicals on the Proposition 65 list known to cause cancer or reproductive harm.
- The Carcinogen Identification Committee (CIC) was established under Proposition 65 to identify the chemicals to add to the Proposition 65 list. The CIC is composed of scientists appointed by the governor to recognize and then vote on the chemicals shown to be carcinogenic through “scientifically valid testing.”
- The CIC meets at least once every year, though it generally is only once (the last meeting was held on December 6, 2021). Before the meetings, the OEHHA will publish a hazard identification document that contains the evidence found on a chemical’s carcinogenicity and solicit public comment on the document. CIC members review the document as well as the public comments received. In addition to written public comments, the CIC will solicit public testimony at the meeting itself.
- If the CIC finds that the chemical “has been clearly shown through scientifically valid testing according to generally accepted principles to cause cancer,” then the members will add the chemical to the Proposition 65 list.
- Bisphenol A (BPA, CAS RN 80-05-7) is a chemical used in a significant number of consumer and industrial applications. BPA is generally utilized in the production of polycarbonate plastics and epoxy resins. Human exposure to BPA generally comes through contaminated food in drinking water. Biomonitoring California data has consistently detected BPA in California residents, but that frequency and level has dropped in recent years as BPA usage has been reduced. BPA was placed in the “high” priority group for evaluation at the November 2020 CIC meeting.
CIC report on BPA carcinogenicity evidence
- The report begins by focusing on the approach utilized by OEHHA, like the National Toxicology Program’s (NTP) 2015 Handbook for Report on Carcinogens, which conducted a systematic approach of literature searches on the carcinogenicity of different chemicals. OEHHA last performed a comprehensive search for literature on the carcinogenicity of BPA in December 2021.
- The report focuses on both carcinogenicity studies in humans and animals as well as mechanistic considerations. OEHHA did not find consistent evidence of a link between BPA exposure and cancer based on epidemiological studies reviewed by the Office. Many of the studies in humans focused on breast cancer, and several more focused on prostate cancer. However, these studies were generally limited by the fact that data was only collected through a single sample, rather than a set of samples collected over time.
- Reviewing the mechanistic considerations regarding BPA, the report summarized that although BPA is rapidly eliminated by the body, the chemical is still consistently detected in human urine samples, indicating widespread frequent exposures. In addition, the report posited that adipose tissue may serve as a “reservoir” to store BPA in the body, which could contribute to that consistent detection.
- The “key characteristics” of carcinogens are a set of ten markers that indicate carcinogenicity and aid in the mechanistic studies of carcinogenicity. One of the major key characteristics of carcinogenicity is genotoxicity. OEHHA noted that a “substantial amount of data” on BPA-induced damage to DNA was available, including more than ten studies that reported a statistically significant relationship between BPA exposure and biomarkers for DNA damage.
Plan for CIC meeting
- The CIC will begin the meeting with a suite of opening remarks as well as swearing in new members on the Committee. The Committee will then turn to considering BPA for listing in Proposition 65. That section of the meeting will begin with a staff presentation on the evidence found as well as a committee discussion on that presentation.
- After the committee discussion on the staff presentation, the CIC will turn to public comments and testimony. After discussing the public comments and testimony, the CIC will decide whether BPA “has been clearly shown through scientifically valid testing according to generally accepted principles to cause cancer” and whether to list the substance in Proposition 65.
- The meeting will take place on Wednesday, December 14 at 10:00AM PT. Requests to speak at the meeting can be made at the link here, and the link to the webcast is available here.
- If the CIC decides that BPA has been clearly shown to cause cancer, the Committee will vote to add the chemical to the list. OEHHA will then publish a revised Proposition 65 list, which will require businesses to provide warnings to customers for significant exposure to BPA. As BPA is used in many industrial or consumer products, the warning requirements and burden could be widespread across industries. The OEHHA would also likely provide draft safe harbor warning language soon after the listing to provide companies with the knowledge of how to properly label BPA-containing products without incurring regulatory ire.
- If CIC votes that BPA has not been clearly shown to cause cancer (or if the CIC decides to defer the vote to gather additional research), OEHHA will give notice of the decision.