Work safety inspectors were forced to call for police back-up after the brothel operator refused to let them into the premises, during a sweep of all 15 of Canberra's brothels and adult entertainment venues last Wednesday and Thursday.

Commissioner Greg Jones said his team had a legal right of entry to inspect workplaces, and the operator could face prosecution or a fine for failing to let inspectors in.

He said the operator was aware of this right, but WorkSafe had reminded them of their legal responsibilities, and was investigating that failure further. Mr Jones declined to say which brothel it was pending possible legal action.

"There were no issues after that, we were able to complete the inspection once police assisted us with our right of entry," Mr Jones said.

The brothel was slapped with three prohibition notices for hazards that had not been identified by inspectors before.

Venues that were shut down last year over similar issues passed this round of inspections, Mr Jones said.

"The main issues we found [at the Fyshwick brothel] were fire safety issues, mainly blocked fire exits, a lack of fire extinguishers and out-of-date extinguishers, frayed cords on electrical equipment, and general hygiene particularly around bathroom showers," he said.

Mr Jones said the mould was so "extensive" around the bathroom floors, walls and ceilings that it was a health risk for staff and clients and could have caused respiratory issues.

He was unable to say when the brothel would be allowed to reopen.

"It will depend on when all the matters are fixed or corrected, when all the fire exists are cleared and all the extinguishers are in date," Mr Jones said.

"Any blockage to a fire exit is extremely serious. If there is a fire and a bit of panic, if there are additional locks or padlocks or equipment in front of the emergency exits it is possible that someone could perish in a fire.

"The extensive mould issues need to be cleaned by a qualified hygienist who'll issue a certification to say the place is hygienic from a contaminants point."

While inspectors picked up issues in other venues, they could either be quickly fixed or weren't serious enough to warrant a forced closure.

One of the issues that was picked up was to do with duress alarms, however Mr Jones said the problem had been fixed.

Last week's inspections follow a series of raids last year, where WorkSafe placed prohibition and improvement notices on five escort businesses after finding problems with mould, electrical and fire safety.

Despite this, Scarlet Alliance chief executive Jules Kim said she had not encountered widespread health hazards when she last did outreach in the ACT.

She said the regulation of sex work in the ACT meant there was much more transparency about the operation of the industry, and that breaches with workplace health and safety could be better dealt with.

"It is an occupation and a workplace and like with another other occupation you deal with sometimes there's good workplaces and bad workplaces, but it's about sex workers having mechanisms to seek redress in situations where health and safety was at risk," Ms Kim said.

However AIDS Action Council ACT executive director Phillipa Moss said several brothel operators rang her last week after the inspections, after WorkSafe wrongly told them their staff had to undergo mandatory STI testing.

While mandatory testing is legally enforceable in other jurisdictions, it is only advisable in the ACT.

Ms Moss said also said it was "generally a good industry" and that this prohibition notice was only newsworthy because of the stigma associated with sex work.

"For the most part brothels and studios in the ACT respect the relevant laws and WHS requirements and potentially this is just a blip like in any other industry. Probably a lot is being made of it because of the police presence and stigma. If it was mould in a restaurant it would be different," Ms Moss said.

This prohibition notice comes after WorkSafe forcibly shut down the Hume Materials Recovery Centre for a week after discovering a number of hazards, including blocked fire exits and missing guard rails and fire extinguishers.

Recycling from yellow lid bins from Canberra and from the broader region were dumped in landfill after being stockpiled at the Hume tip due to the closure.

It also comes as WorkSafe is undergoing a restructure, after an external review found the agency lacked the resources to identify and respond to emerging work safety issues across different industries.

Despite this, Mr Jones said WorkSafe would continue to closely monitor the health and safety compliance of all businesses, including brothels.

He said the work safety watchdog would focus on the safety of young workers in particular this year, across the industries of hairdressing, healthcare and automotive.