In principle, but otoh it makes a lot of sense to train with the same stuff you use for real. That being said, recently non-flourinated firefighting foams have

In principle, but otoh it makes a lot of sense to train with the same stuff you use for real. That being said, recently non-flourinated firefighting foams have been developed (based on some sugars IIRC), so there's hope these will be able to replace the old stuff.