New Delhi, May 29 -- Australia is suing U.S. conglomerate 3M for more than 2 billion Australian dollars ($1.4 billion) over so-called "forever chemical" contamination from firefighting foam at defense bases, the government said on Thursday.

The government's largest-ever claim for compensation relates to contamination with per- and polyfluoroaklyl 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.

3M said it would fight Australia's claim.

"3M has never manufactured PFAS in Australia and ceased sales of the products at ...