F.D.A. Bans 65 Mask Manufacturers

Citing poor quality, the Food and Drug Administration prohibited dozens of companies from continuing to sell their N95-style face masks here.

The Food and Drug Administration on Thursday barred more than 65 manufacturers in China from exporting N95-style face masks to the United States, citing poor quality.

In doing so, the F.D.A. slashed the number of Chinese companies approved to sell the masks in the U.S. to 14 from 80.

N95 masks, which provide better protection against coronavirus particles than cloth or surgical masks, are coveted by health care providers and emergency medical workers. On April 3, drastic shortages of the N95 masks led the F.D.A. to allow imports of similar masks from China.

These imported masks, known as KN95, were never tested by American regulators, but were required to be vetted by an accredited test laboratory showing that they met the standards of the Centers for Disease Control and Prevention. Those standards call for filtering 95 percent of particles that are 0.3 microns or larger, including the new coronavirus.

As an additional safeguard, the C.D.C. and the F.D.A. initiated their own review to make sure the masks met these performance standards. On Thursday, the F.D.A. said that too many of the Chinese imports failed to filter out a sufficient percentage of particles. Test results showed that numerous companies that were authorized to sell the masks in the U.S. flunked, with one product removing as little as 24 to 35 percent. The health agencies also tested some KN95 masks that did not have agency approval. One of these, the F.D.A. said, blocked roughly 1 percent of the particles.