Registered nurse Diane Miller pulls on an N-95 mask as she enters the "red zone" before heading into a patient's room in the COVID Acute Care Unit at UW Medical Center - Montlake, Tuesday, Jan. 26, 2021, in Seattle. Credit: Elaine Thompson / AP

BOSTON — A sharp-eyed worker at a Massachusetts hospital is being credited with spotting a shipment of tens of thousands of counterfeit N95 surgical masks that could have potentially put the health of frontline medical workers at risk, officials said Monday.

Masks and other protective equipment have been in high demand during the coronavirus pandemic, leading to shortages of many products.

James “Barry” O’Shaughnessy, the manager of procurement of South Shore Health in Weymouth with 25 years of experience, recently placed an order for 30,000 masks — but when they arrived, he noticed something was awry.

“The labels on the boxes were placed differently than other shipments,” O’Shaughnessy said in a statement. “And the plastic bag inside the boxes had a strange seal. My gut told me something was off.”

He asked a 3M representative to help inspect the third-party masks that were not from a 3M-authorized distributor.

“I sent 20-30 photos of the product to 3M and the representative confirmed my suspicion. The masks were counterfeit,” he said.

The Department of Homeland Security seized the masks and is investigating.

“Barry’s deep experience and keen attention to detail helped protect thousands of South Shore Health employees from wearing counterfeit masks that would put them at risk,” President and CEO Dr. Allen Smith said. “We are grateful for his watchful eyes and dedication to the safety of our colleagues.”