A favorite staple of American diets - chicken breasts, legs and wings - could become safer to eat.

Standards proposed Wednesday by the Agriculture Department aim to reduce rates of salmonella and campylobacter, another pathogen that can cause symptoms similar to salmonella, in chicken parts, ground chicken and ground turkey. The standards would be voluntary but designed to pressure companies to take steps to reduce contamination.

USDA says the proposed standards could reduce raw poultry-related foodborne illnesses by about a quarter, or 50,000 illnesses a year. Among the measures companies could take to reduce the rates of the salmonella and campylobacter: better screening of flocks and better sanitation.

The proposal would ask poultry producers to reduce the rates of salmonella in raw chicken parts from an estimated 24 percent now to less than 16 percent, and campylobacter rates in raw chicken parts from an estimated 22 percent to 8 percent. Rates also would be reduced in ground chicken and turkey, and sampling would be done over a longer period of time to ensure accuracy.

Agriculture Secretary Tom Vilsack said companies should realize that complying is good business. "It's in the long-term best interest of the market to have safer food," Vilsack said.

Ashley Peterson of the National Chicken Council said the industry has already made improvements. She said poultry companies have been exploring options to reduce contamination, including strengthened sanitation programs, temperature controls and ways of processing.

Once the standards are put in place, "we will be meeting or exceeding the standards," she said.

The standards come after a lengthy outbreak of salmonella illnesses linked to California chicken company Foster Farms, which sickened more than 600 people between March 2013 and July 2014. In 2013, USDA said inspectors at Foster Farms facilities had documented "fecal material on carcasses" along with poor sanitation.

Foster Farms took measures to improve its sanitation and screening, and the Centers for Disease Control and Prevention later said the company's products were down to 5 percent contamination.

Vilsack said the Foster Farms outbreaks led the department to realize it needed to be more focused on reducing salmonella in chicken parts. The department already had standards in place for whole carcasses, but not individual parts like breasts and wings. The new proposal would cover the various parts, which the USDA says is about 80 percent of chicken available for purchase.

USDA also would make public which companies are meeting the standards or going beyond them, and which companies have more work to do, giving companies more incentive to comply.

Consumer advocates have lobbied for more stringent standards, saying the sale of raw poultry contaminated with salmonella should be illegal. Current law allows raw poultry to have a certain amount of salmonella because it is so prevalent and is killed if consumers handle and cook the meat properly.

By comparison, it is illegal to sell meat contaminated with E. coli, which can cause severe illness or death.

Caroline Smith DeWaal of the Center for Science in the Public Interest said the proposed standards would be better if they were enforced.

"USDA can't close a facility that fails to meet these standards," she said.

Around 1 million Americans get sick from salmonella every year, and almost 20 percent of those illnesses are linked to chicken and turkey.