Silverdale Fire Station has been locked down after a possible asbestos contamination, just three days after Auckland City Fire Station was also forced to close its doors when asbestos was found on site.

Fire and Emergency NZ Auckland region manager Ron Devlin said contractors were carrying out scheduled work at the Silverdale station on Sunday morning when dust was spotted in an engine bay after a call-out.

The station remained closed overnight as a precaution while the dust is tested, Devlin said.

The duty volunteer crew were still going through decontamination procedures at 5 pm.

"The health, safety and well-being of our people are paramount.

"We have standard operating procedures for incidents involving hazardous materials, or where these may be present, and our response today follows those procedures," Devlin said.

New Zealand Professional Firefighters Union Auckland secretary Martin Campbell called the second incident "a bit of an eye-rolling experience for all involved".

"Although it's more of a precautionary measure this time, once again it's a no one in, no one out the situation," Campbell said.

Asbestos can cause asbestosis, a chronic lung condition caused by inhaling asbestos fibre.

Long-term exposure to asbestos can scar lung tissue and cause shortness of breath.

It can range from mild to severe and often lies dormant until many years after a person is first exposed.

Asbestos can also cause mesothelioma, a type of cancer that occurs in the thin layer of tissue covering most internal organs. It's an aggressive and deadly cancer, according to the Mayo Clinic.

* This story originally appeared on Stuff.