California Assemblywoman Leticia Castillo on Tuesday unveiled legislation requiring businesses to maintain sex-separated bathrooms, locker rooms, showers, and changing areas, except in the case of single-occupancy gender-neutral facilities.

The measure would apply to gyms, spas, and other locations where individuals have a reasonable expectation of privacy. Castillo described the proposal as a “commonsense” effort to ensure women and girls are not required to share intimate spaces with biological males.

“Parents across California are asking for clarity and commonsense protections in intimate spaces where females deserve privacy and safety,” Castillo said in a statement. She emphasized that the bill seeks to protect civil rights while preserving sex-based distinctions in private facilities.

The legislation comes amid ongoing debate in California over policies allowing individuals to access facilities consistent with their gender identity. Advocacy organizations such as Our Duty USA have backed Castillo’s proposal, arguing that existing policies create vulnerabilities in spaces traditionally reserved for women.

Supporters of the bill point to several high-profile incidents. In 2021, a registered sex offender, Darren Merager, was accused of exposing himself in the women’s section of WiSpa in Los Angeles. He was later found not guilty of indecent exposure. In another case, a Planet Fitness location in San Francisco canceled the membership of a male individual after a woman reported witnessing inappropriate conduct in a women’s locker room.

Other gym patrons in the San Francisco area have publicly described discomfort and distress over biological males accessing female facilities. Some families, including members of religious communities, have reportedly withdrawn from gyms following such encounters.

Groups, including the American Civil Liberties Union, argue that California civil rights law prohibits businesses from denying restroom access based on gender identity. Guidance from state Attorney General Rob Bonta states that entities may not restrict access to bathrooms in a manner that conflicts with state anti-discrimination protections.

California Democrats have largely opposed efforts to roll back gender-identity policies. Last year, a proposal to restrict the placement of biological male sex offenders in female prisons failed to advance in committee.

Castillo’s bill is expected to face significant opposition in the Democrat-controlled legislature. Supporters say it represents a broader push to reestablish sex-based protections in state law, while critics argue it would conflict with existing anti-discrimination statutes.