"We're concerned about these anonymous claims and while we currently have no evidence they're true."
Poultry workers in the United States are routinely denied bathroom breaks to the point of being forced to wear diapers while on the production line, a new report claims.
The "vast majority" of 250,000 workers in the sector are mocked, ignored or threatened with being fired when they ask to go to the bathroom, Oxfam America said in the study.
"Workers struggle to cope with this denial of a basic human need. They urinate and defecate while standing on the line; they wear diapers to work," said the recently-released report.
The US arm of the global anti-poverty charity added that workers would take on dangerously low levels of liquids, enduring pain and discomfort while risking serious health problems.
The group quoted anonymous workers at Tyson Foods, Perdue Farms, Pilgrim's Pride and Sanderson Farms, which between them have 100,000 workers and account for 60 percent of the sector.
Tyson, one of the biggest poultry firms in the world, said in a statement it would "not tolerate the denial of requests to use the bathroom" in its factories.
"We're concerned about these anonymous claims and while we currently have no evidence they're true, are checking to make sure our position on restroom breaks is being followed," it said.
Oxfam cites a survey of 266 workers in Alabama conducted by the anti-discrimination Southern Poverty Law Center which said "nearly 80 percent said they are not allowed to take bathroom breaks when needed."
"A recent survey in Minnesota revealed that 86 percent of workers interviewed said they get fewer than two bathroom breaks in a week," Oxfam added.
The charity added that the few employees who say they are allowed to relieve themselves whenever they wish work in plants that are unionized, around one third of the total.
Supervisors deny workers permission to leave the production line because they are under intense pressure to keep up with production or meet daily quotas, the report said.
Workers were waiting an hour or more and then racing across vast, often slippery workshop floors to accomplish the task quickly enough to avoid being disciplined, Oxfam added.
"While the poultry industry today enjoys record profits and pumps out billions of chickens, the reality of life inside the processing plant remains grim and dangerous," the report went on.
"Workers earn low wages, suffer elevated rates of injury and illness, toil in difficult conditions, and have little voice in the workplace."
Oxfam called on the companies to deploy "floating" workers to step in temporarily when employees needed to leave the line, ensuring production would not be halted.
Tyson Foods says it has met with Oxfam and has already complied with the request. Perdue, Sanderson and Pilgrim's were not immediately available for comment.