Australia is suing US conglomerate 3M for more than AU$2 billion (US$1.4 billion) over so-called ‘forever chemical’ contamination from firefighting foam at defence bases, the government said on Thursday.

The government's largest-ever claim for compensation relates to contamination with per- and polyfluoroalkyl substances, known as PFAS, at 28 bases. Human-made PFAS are commonly referred to as ‘forever chemicals’ because they don't break down naturally.

Australia filed the suit in the Federal Court of Australia against Minnesota-based 3M Company and its subsidiary 3M Australia.