LOS ANGELES » A major adult filmmaker sued to block a new Los Angeles County law requiring porn actors to wear condoms, calling it a threat to free expression.

Vivid Entertainment contends that Measure B, passed by county voters last fall, violates the First Amendment right to free speech and expression and is unnecessary because the adult industry already has safeguards, such as regular blood testing of actors, to prevent the spread of AIDS and other venereal diseases.

The suit, filed Thursday in federal court, also contends that the law is vague, burdensome and ineffective and is pre-empted by California laws and regulations. It asks the court to block the measure’s enforcement and to rule it unconstitutional.

A call to the county counsel’s office seeking comment from attorneys involved in the case was not immediately returned.

The measure requires adult film producers to apply for a permit from the county Department of Public Health to shoot sex scenes. Permit fees will finance periodic inspections of film sets to enforce compliance.

However, public health authorities have not announced specific enforcement measures for the law.

The AIDS Healthcare Foundation, which sponsored the initiative, said the measure will help safeguard the public, as well as porn workers, from sexually transmitted infections.

Adult film actors rallied to oppose the law before its November passage.

"The idea of allowing a government employee to come and examine our genitalia while we’re on set is atrocious," sex film star Amber Lynn told the Los Angeles Daily News at the time.

Industry critics also said that fans don’t want to see actors using condoms. They contend that if the law is enforced, the 200 or so companies that now produce adult films in Los Angeles, primarily in the San Fernando Valley, will simply move elsewhere, taking with them as many as 10,000 jobs.

"Overturning this law is something I feel very passionate about. I believe the industry’s current testing system works well," Steven Hirsch, Vivid’s founder and co-chairman, said in a statement. "Since 2004 over 300,000 explicit scenes have been filmed with zero HIV transmission. The new law makes no sense and it imposes a government licensing regime on making films that are protected by the Constitution."

The law also will have "have vast unintended consequences which may undermine industry efforts to protect the health of our actors and actresses," Hirsch said.

Califa Productions, which produces adult films for Vivid, and actors who uses the stage names Kayden Kross and Logan Pierce, joined the suit, which names the county, its district attorney and public health director.