CEPU NSW assistant secretary Shane Murphy said asbestos had a long and damaging history in Australia, and the recent rollout of the NBN had once again resulted in asbestos exposure affecting workers and residents.

He said the abolition of the only federal government body addressing asbestos safety will risk deadly exposure for workers and the community.

"The CEPU NSW is joining asbestos support groups, lawyers, concerned community members and other unions in urging/demanding the federal government to guarantee long-term funding for the Asbestos Safety and Eradication Agency," Mr Murphy said.

"It is vital for a co-ordinated, whole-of-government approach to maintain safeguards for workers and the community.

"Only last year, all work was temporarily stopped in pits and pipelines for the NBN when contractors disturbed asbestos while laying cable in western Sydney.

"This illustrates the ticking time bomb of asbestos out in the community, the continued danger it poses and the very real need for the safety agency.

"The independent safety agency is responsible for implementing a national action plan on asbestos safety and eradication, and was tasked with creating and maintaining Australia's first National Asbestos Exposure Register.

"The future of these two important safeguards is under threat if the agency is abolished."

May 23 marked a milestone for the NBN, as copper services begin winding down in parts of the Kiama area.

The NBN has begun replacing most existing landline home and business phones, ADSL internet and Telstra cable internet services in those parts of Kiama, which were scheduled to be officially switched off from May 23.

An NBN Co spokesperson said ensuring the safety of communities and people working on the NBN was "the most important job we have".

"Every employee of NBN Co has a responsibility to drive the highest standards of safety."