A group of former Amazon warehouse employees is suing the company for systemically discriminating against pregnant workers, accusing the company of denying them basic accommodations and penalizing some who took breaks to pump milk or time off for hospital visits.

The four plaintiffs filed a proposed nationwide class action in a Brooklyn, New York federal court Tuesday, accusing Amazon of violating the 2022 Pregnant Workers Fairness Act, which requires employers with 15 or more workers to provide a “reasonable accommodation” for pregnancy and childbirth related medical conditions. To refuse an accommodation, companies must show it would create “undue hardship” for the business.

“Denying a pregnant worker a stool, a lighter workload, or a bathroom break is a violation of federal law — it’s that simple,” said Inimai Chettiar, president of A Better Balance, a nonprofit organization that is representing the plaintiffs along with the law firm Emery Celli Brinckerhoff Abady Ward & Maazel. “Amazon has built an empire on speed and efficiency — speed and efficiency that too often sacrifices the rights of pregnant workers it refuses to accommodate.”

Amazon denied the accusations, saying the lawsuit’s description of events is inaccurate.