The state government will audit the use and ban the supply of the potentially flammable building cladding that led to London's deadly Grenfell Tower inferno, in what it styles as Australia's toughest fire safety reforms.

The state government said it would introduce reform that would identify buildings encased in unsafe cladding, require them to be inspected and force building owners to foot the bill for replacements and ban the sale and supply of unsafe material.

Better Regulation Minister Matt Kean said the government had undertaken an audit sample of about 180,000 residential and commercial towers constructed in NSW since the 1980s.

About 1000 of those buildings "may have [unsafe] cladding", the Minister said.