At least two workers at the Jeeralang power station in the Latrobe Valley, east of Melbourne, have been exposed to asbestos while undertaking maintenance work at the plant.

Key points: During work on the old power station a component containing asbestos was encountered.

During work on the old power station a component containing asbestos was encountered. CFMEU claims procedures were not fully followed

CFMEU claims procedures were not fully followed Energy Australia says work stopped immediately asbestos was suspected

The Construction, Forestry, Mining and Energy Union (CFMEU) said the two workers were removing a piece of plant in the duct work around a gas turbine when they were "showered with" asbestos.

Jeeralang is a gas power station located outside the town which was built in the 1970s and has a capacity of 450 megawatts.

The plant's owner, Energy Australia, has confirmed two workers were working in an area where a component was "identified as potentially containing asbestos" on Thursday, July 4 and in a statement said the matter had been reported to WorkSafe.

The CFMEU's construction and general organiser for Gippsland, Toby Thornton, said potentially more people could have been exposed.

"There seems to be an oversight in compliance to those regulations and procedures when you suspect that any piece of plant would contain asbestos," Mr Thornton.

"That hadn't been adhered to and the workers were given direction to remove a piece of plant in a duct work around a turbine and unfortunately they were showered with a substance or a material which later on was identified as asbestos," Mr Thornton said.

The two men, one from the Latrobe Valley and the other from the Sale area, were the only two directly exposed to the asbestos but the union said that because of the large amount of asbestos released and wind conditions on the day, other parts of the site were contaminated.

Mr Thornton also claimed procedures were not followed and the workers did not have the appropriate decontamination and said the workers went to the other facilities including offices, potentially exposing other people.

We 'responded appropriately': Energy Australia

An Energy Australia spokesman said the workers were removing an expansion joint, which is used to connect two sections of pipeline, which was "identified as potentially containing asbestos".

"The operator in charge at Jeeralang, as he had been trained to do, had the workers stop work immediately on that section of the plant. The area was sectioned off, so no other workers could enter," he said.

"The material was tested. Late Friday on July 5, the following day, results showed it was asbestos."

Energy Australia said its people "responded appropriately and according to our processes" and arranged for specialists certified in asbestos removal and disposal to visit the plant on Monday.

In the statement, the spokesman said the area had been cleaned and a clearance certificate issued to allow work to resume in the area.

"We are complying with WorkSafe Victoria's investigation of the incident and with the notices it has issued," he said.

Workers shocked and disappointed

The two workers are power industry veterans who were working for a maintenance contractor at the time of their exposure.

Mr Thornton said they were still working at the site and were in a "bit of shock" and disappointed by their exposure.

"They've all worked in the power industry before at all the major sites. They have a very strict policy that if you suspect a material is asbestos you treat it as asbestos," he said.

"This didn't happen on this occasion so they are more disappointed that they potentially could have been exposed."

The Jeeralang power station was purchased by Energy Australia in April 2018.

Long-term risk from asbestos

Asbestos can cause a variety of conditions including asbestosis and mesothelioma, but asbestos-related diseases can take decades to manifest.

The chief executive of the Asbestos Council of Victoria, Vicki Hamilton, said she was "amazed there was not an awareness of what they were doing at this job".

"One exposure is just as bad as a whole heap. There is no dose-related response to this.

"So we just sit and wait, it's like a ticking time bomb," Ms Hamilton said.

She said her organisation had been notified of the exposure by the CFMEU and was making counsellors available for the affected workers.

A WorkSafe spokeswoman said WorkSafe had visited the site and enquiries were continuing.