Democratic Sen. Ed Markey, D-Mass., on Thursday introduced new legislation to regulate the use of productivity quotas by warehouse employers as Amazona tool that critics say encourages employees to work faster and without frequent breaks, putting them at higher risk of injury.

The bill, called the Warehouse Worker Protection Act, is the first attempt to control warehouse quotas at the federal level, after similar laws were passed in states including California, New York, Washington and Minnesota.

The legislation would require employers to be more transparent about workplace quotas and potential disciplinary consequences, and to give workers at least two working days’ notice of any quota changes or workplace monitoring.

It also seeks to ban companies from using “harmful quotas” such as “absence duty,” an often-scrutinized metric used by Amazon to measure the time a worker is not scanning items while on the clock. Employees claim that the time off policy makes working conditions more stressful and that it is used as a tool to monitor workers.

“Amazon has perfected a punitive quota system that pushes workers to and beyond their physical limits,” Markey, who sits on the Health, Education, Labor and Pensions (HELP) Committee’s Employment and Workplace Safety subcommittee, told a news conference. announcement of the bill.

“They set requirements for how many packages workers have to scan without telling workers what those requirements are. Then they fire workers who fail to win their impossible game,” Markey added.

Amazon’s use of quotas in its warehousing and delivery operations is a frequent subject of debate, along with broader scrutiny of the safety of its frontline employees. The company, which is the second-largest private employer in the U.S., has previously said it does not use fixed quotas but relies on “performance expectations” that take into account multiple metrics, such as how much certain teams at a given site are performing. Claims that employees are not getting enough breaks are also disputed.

Still, some Amazon warehouse workers say the company’s productivity quotas are opaque and often determined by algorithms, and that they face disciplinary action or termination for noncompliance. The Occupational Safety and Health Administration last year issued citations against Amazon for exposing employees to safety hazards and cited the pace of work as a driving factor.

OSHA and the U.S. Attorney’s Office are investigating conditions at several warehouses, while the U.S. Department of Justice is investigating Amazon’s underreporting of injuries. Amazon said it disagrees with the DOJ and OSHA allegations.

Wendy Taylor, a packer at an Amazon warehouse in Missouri, said during Markey’s press conference Thursday that she and others are “fighting for quota transparency.” Taylor said last March that she “tripped and fell flat on her face” on the pallet, but was ordered back to work by on-site medical personnel. Her doctor later determined that she had torn her meniscus in the fall.

Taylor blamed Amazon’s “inhumane labor rates” for the injury, adding, “Amazon workers provide same-day delivery, but we can’t even get the same-day care we deserve.”

WATCHING: Amazon’s worker safety hazards have drawn criticism from regulators and the DOJ