More than 40 Republican and Democratic senators recently submitted a letter to The Department of Labor’s Secretary Thomas Perez demanding the Occupational Safety and Health Administration (OSHA) stop its unlawful regulation of family farms.

Under the Occupational Safety and Health Act of 1976, Congress prohibited OSHA from using appropriated funds to apply requirements to farming operations with 10 or fewer employees. In 2011, a memo issued by OSHA stated that many farming activities—including drying and fumigating grain—are subject to all OSHA requirements. Under this change, the agency’s regulations expanded to nearly every farm in the country, according to the Farm Bureau News.

The senators say OSHA has clearly overstepped regulatory boundaries established by Congress.

“Worker safety is an important concern for all of us—including the many farmers who probably know better than OSHA regulators how to keep themselves and their employees safe on farms,” the letter said. “If the administration believes that OSHA should be able to enforce its regulations on farms, it should make that case to Congress rather than twisting the law in the service of bureaucratic mission creep.”

By Feb. 1, the Senators have asked OSHA to stop all actions based on its incorrect interpretation of the law, issue a guidance correcting the misinterpretation and provide a list and description of regulatory actions taken against farms with incorrectly categorized non-farming activities since the June 2011 memo.