Report AR-AFFF required? Laboratory solvents in Fire Risk Assessments Posted December 1, 2020 So, for those interested. I finally got to the bottom of this. The reason why the fire risk assessors have stated that our current fire extinguishers are suitable, is that they will subdue a solvent fire long enough to allow an escape, with the caveat that the fire might well re-ignite once the solvent has completely destroyed the foam blanket. Quite why they think it's sensible to recommend fire extinguishers which may not actually extinguish a fire, is beyond me, but at least I can understand their rationale.