SEATTLE, Wash. (AP) — Dozens of Washington state hospitals have learned N95 respirator masks from 3M Company are counterfeits.

The Seattle Times reports the Washington State Hospital Association alerted the state’s hospitals about a notification from 3M that some masks were knockoffs that were not actually manufactured by the company.

The association has asked the state’s 115 hospitals to sort through mask supplies and pull potentially affected equipment.

It’s not clear whether the counterfeit masks are less safe than those manufactured by 3M.