Class-action risk: Comply now with PUMP Act.

The Providing Urgent Maternal Protections for Nursing Mothers Act, a new federal law that greatly expanded the right of new mothers to express breast milk for their infants through unlimited breaks during the workday, went into effect in April. The PUMP Act gave employees the right to sue their employers in federal court if they were denied milk expression breaks in a private location that's not a bathroom.

Now, just months later, the first PUMP Act lawsuit has been filed, on behalf of all similarly situated employees of the U.S. Postal Service.

Recent case: Christy, Taylor and Melissa work for the post office. After Christy gave birth to her fifth child and returned to work, she claims she was forced to pump milk in a break room, which she says was neither private nor clean and where she was frequently interrupted. Taylor says she was forced to pump in the cargo area of a mail truck after returning to work. Melissa likewise claims she was denied a clean, private area to pump and was relegated to a mail truck.

All three employees claim that the lack of adequate breaks and privacy led to milk reduction, stress and anxiety.

Their class-action lawsuit alleges there is a...