The California Office of Environmental Health Hazard Assessment’s (OEHHA) has extended the comment period on its proposal to amend Section 25821(a) and (c) of the Proposition 65 regulations, which dictate how to calculate exposure to reproductive toxicants for average consumers. Comments are now due by December 3, 2018. The Safe Drinking Water and Toxic Enforcement Act of 1986, also known as Proposition 65, prohibits a company from knowingly exposing any individual to a listed chemical without first providing a "clear and reasonable warning"" to such individual. The law provides an exemption from the need to provide a warning where exposures are below a "safe harbor."

Currently, Section 25821 requires simply that exposure be determined by multiplying the “level in question” (i.e., the concentration of a chemical in a given medium) by the reasonably anticipated rate of exposure to the chemical by the average users of the consumer product. The proposed amendments would make two changes.  First, the proposal would amend Section 25821(a) to clarify that where a business presents evidence of the “level in question” of a listed chemical in food based on the average of multiple samples of that food, the level in question cannot be calculated by averaging the chemical’s concentration in foods from various lots (i.e., “by averaging the concentration of the chemical in food products from different manufacturers or producers, or that were manufactured in different manufacturing facilities from the product at issue”). Second, the proposal would amend Section 25821(c)(2) to require that exposures to reproductive toxicants from consumer products be calculated as the arithmetic mean of the rate of intake or exposure for product users (as opposed to the geometric mean).

The proposed amendments are in response to the 2015 appellate decision Environmental Law Foundation v Beechnut Nutrition Corp. et al. case, in which Section 25821 was interpreted to allow the averaging of concentrations of lead in multiple lots and to allow use of the geometric mean when calculating individual exposures. The extension was requested by the California Chamber of Commerce and Grocery Manufacturers Association.