California had about 1.9 million high school students enrolled in more than 4,000 schools last year, according to the California Department of Education.

“This bill would create an unfunded mandate to public schools that should be considered in the annual budget process,” Newsom wrote in a message explaining why he vetoed the bill, known as Senate bill 541.

The bill is one of hundreds passed by California's Democratic-dominated state Legislature before lawmakers adjourned last month. Newsom has been signing and vetoing legislation since then, including rejecting bills on Saturday to ban caste-based discrimination, limit the price of insulin and decriminalize possession and use of some hallucinogens.

The bill would have required all public schools that have grades nine through 12 to make condoms available for free to all students. It would have required public schools with grades seven through 12 to allow condoms to be made available as part of educational or public health programs.

And it would have made it illegal for retailers to refuse to sell condoms to youth.

State Sen. Caroline Menjivar, a Democrat from Los Angeles and the author of the bill, had argued the bill would have helped “youth who decide to become sexually active to protect themselves and their partners from (sexually transmitted infections), while also removing barriers that potentially shame them and lead to unsafe sex.”

Newsom said programs increasing access to condoms are “important to supporting improved adolescent sexual health.” But he said this bill was one of several measures lawmakers passed this year that, when added together, would add $19 billion in costs to the state budget.

“With our state facing continuing economic risk and revenue uncertainty, it is important to remain disciplined when considering bills with significant fiscal implications, such as this measure,” Newsom said.

Also on Sunday, Newsom signed a law aimed a electrifying the state's fleet of school buses. Starting in 2035, the law will require any new bus purchased or contracted by school districts to be zero-emission.

California's public school districts that provide their own transportation own about 15,800 school buses, of which 10,800 are powered by diesel fuel, according to a 2022 report from the Legislative Analyst's Office.

The law is part of California's plan to phase out the use of fossil fuels. State regulations will ban the sale of new gas-powered cars in California by 2035.?