SACRAMENTO, Calif. (AP) — Farmers could be tossed in jail and fined thousands of dollars if they fail to provide field workers with adequate water and shade under a bill that passed the state Senate on Tuesday.

California regulations already require growers to protect their workers from extreme heat, but the rules are enforced with civil penalties by the California Division of Occupational Safety and Health. Under AB2676, which passed on a party line 24-12 vote over Republicans' opposition, violations would be classified as misdemeanors, punishable by up to six months in jail and a $10,000 fine.

If a violation results in injury, farmers could face up to a year in a county jail and a fine of up to $25,000.

The bill returns to the Assembly for a final vote.

Prosecutors need the criminal penalties if they are to enforce the law, said Sen. Loni Hancock, D-Berkeley.

"It is a sad state of affairs that our current laws provide greater protections for animals than they do for farmworkers," Hancock said.

Republican senators said that argument is offensive to responsible growers. They said criminal penalties aren't necessary when current law already can be enforced by state safety regulators.

"By and large, farmers treat their employees well and humanely," said Sen. Doug La Malfa, R-Willows.

He and other Republican lawmakers objected that the measure is the second approved by the Senate in two days that would make it more difficult for growers to operate. On Monday, senators approved a bill requiring that farmworkers be paid overtime after working an eight-hour day or 40 hours in a week, the same as other non-management employees.

The bills will eliminate farmworkers' jobs by encouraging growers to shift to crops that can be harvested by machine, opponents said.

The heat safety bill is backed by both the United Farm Workers and The Humane Society of the United States, and opposed by the California Farm Bureau Federation and other groups representing growers and businesses.

At least 14 farmworkers have died of heat-related causes since 2005, when California adopted the nation's first rules requiring shade and water for the state's 450,000 farmworkers. Two deaths this summer are being investigated.