On October 13, 2021, the U.S. Center for Environmental Health (CEH) issued a 60-day non-compliance notice to multiple brands, manufacturers and retailers for bisphenol A (BPA) concentrations in socks placed on the California market exceeding The maximum allowable dose level (MADL) of California 65 is exceeded without providing a California 65 warning label on the product.

A "60-Day Notice of Violation" is a legal document sent to businesses that violate California's Proposition 65 requirements. Typically, the notice prompts the parties to negotiate, potentially reaching a settlement agreement with re-enactment or determination of concentration requirements. On May 15, 2022, California Proposition 65 released the first settlement for BPA in socks. The details are as follows:

BPA is a phenolic compound used in the manufacture of polycarbonate and epoxy resin, can be used as a developer for thermal paper, and is widely used in the production of plasticizers, flame retardants, antioxidants, heat stabilizers, Rubber antioxidants, pesticides, coatings and other fine chemical products. Due to its structural and biological similarities, in addition to BPA, it also includes BPS, BPF, BPB, BPC, etc., which can be used as dye-fixing agents or spinning aids for polyester and polyamide textiles, BPS and BPF are available in chrome-free tanned leather.

As an endocrine disruptor, BPA has certain embryotoxicity and teratogenicity. High concentrations of BPA exhibit hormonal activity and endocrine disrupting properties in humans and the environment.