Health officials in California have said the recent infection of two porn actors with the HIV virus means they may force performers to wear condoms.
The California porn industry's profits are said to rival Hollywood's
Los Angeles County officials said they believed existing regulations gave them the authority to require condom use.
And the state Division of Occupational Health and Safety is also planning to carry out inspections of productions next week, the LA Times reported.
The California-based porn industry is worth billions of dollars a year.
Around 200 production companies in California make an estimated 4,000 films a year for public consumption, using around 1,200 performers, ABC News reported.
And analysts have warned that most porn producers and distributors would not switch to condom-only productions as consumers did not like to see them being used in films.
However, several companies have now joined a two-month shutdown after the two performers tested positive for HIV, the virus that can cause Aids.
Around 12 production companies have stopped production until 8 June and two companies - Hustler Video and VCA Pictures - say they have halted work indefinitely.
"The main concern of both companies right now is for the health and well-being of the talent they work with," VCA publicist Mischa Allen told the Associated Press news agency.
The industry's largest studio, Vivid Entertainment Group, has also stopped shooting, AP said.
More than 1,000 performers are tested for HIV every three weeks by the Adult Industry Medical Healthcare Foundation (Aim).
The foundation ensures that performers are tested every 30 days for the disease.
But executive director Sharon Mitchell said she thought it unlikely that all companies would halt work.
"You've got to understand this is pornography," she told ABC News.
"It doesn't shut down for Christmas and I'm afraid it won't shut down for HIV. Not all of it anyway."
The veteran male performer who tested positive earlier this week is thought to be the first since 1999.
It is thought that he contracted the virus while filming in Brazil and later passed the virus to a porn actress, AP reports.
Dozens of other performers who had recently come into contact with him have been quarantined and will not be permitted to work until they test negative for HIV.
BBC arts correspondent Lawrence Pollard says the timing of the scare is unfortunate, as the US is currently in the midst of a debate over taste and decency in the media which could become an election issue.
The porn industry will not want to draw more attention from politicians keen to advocate greater regulation of their activities, our correspondent adds.