As fears over the swine flu appear to be subsiding, a local congressman and union representatives for U.S. Customs and Border Protection employees continue to criticize the Department of Homeland Security because of what they say are fuzzy regulations on the use of protective masks.

Employees who screen people as the come into the country through ports of entry, including those at San Ysidro and Otay Mesa, have been told not to wear the masks as a precaution against the swine flu virus, union officials say.

Following complaints from the union and some lawmakers, Homeland Security issued a memo April 27 outlining interim guidelines for use of masks. The guidelines say that employees should wear a mask if they come into contact with someone who shows signs of the flu. But the guidelines are silent on whether officers, especially those who screen large numbers of people at the border, should wear a mask as a precaution.

"It's ridiculous," U.S. Rep. Brian Bilbray said Friday. "Everyone knows that the policy is absurd."

Two weeks ago, U.S. Rep. Duncan D. Hunter, R-El Cajon, also called on the department to allow employees to wear protective masks.

Bilbray, R-Solana Beach, said frontline workers should be given the right to decide whether to don a mask. Asking them to wear one after they've come into contact with someone who shows signs of sickness is too late, he said.

The congressman questioned Homeland Security Undersecretary for Management Elaine Duke on the issue Thursday at a House subcommittee hearing.

Duke told the committee that the department based its decisions on the recommendations of the Centers for Disease Control and Prevention. Duke also acknowledged that some local Customs and Border Protection supervisors at border crossings had barred officers from wearing masks while screening people.

Colleen Kelley, president of the National Treasury Employees Union, said the union has received numerous complaints from workers whose supervisors have told them not to wear the masks. The union represents about 150,000 federal workers, including 22,000 Customs and Border Protection employees.

"Some of (the complaints) are disturbingly threatening, and some include comments indicating the reason for the prohibition was fear of alarming the public," Kelley said in a written statement on Thursday.

The affidavits from employees, which the union offered as evidence, date the incidents from late April through May 8, including two employee complaints at the Otay Port of Entry. The names of the employees and the supervisors involved in the incidents were not released.

A spokesman for the department in San Diego referred questions on the issue to officials in Washington.

Homeland Security spokeswoman Amy Kudwa in Washington, said on Friday there is no policy prohibiting employees from wearing masks. She said the department is continuing to review the matter.

Contact staff writer Edward Sifuentes at 760-740-3511.