A discussion session with conference participants, on smoke toxicity, was organised by AMI and pinfa following the CREPIM report presentation.
• Smoke is always toxic. Previous major studies have concluded that it is not meaningful to attempt to differentiate low smoke materials, for example the University of Pittsburgh methods developed for New York State were never implemented into regulation (see https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4914232/pdf/jresv97n2p245_a1b.pdf)
- The importance of smoke opacity in hindering escape, and so in fire safety
- Variation in regulations and standards for smoke, covering opacity, total smoke particle emissions, smoke corrosivity, smoke toxicity
- Regulations addressing smoke toxicity only look at acute toxicity (carbon monoxide, irritant and asphyxiant gases). Results may not be indicative of real fire situations.
- The environmental impacts of accidental fire smoke and gas emissions should be considered, and not only their immediate toxicity
To where does the phosphorus from P-containing PIN FRs go in fires? Experts present indicated that it is generally not found significantly in fire gases, and is probably retained in char as phosphate or polyphosphates. This indeed is usually the objective, because it is the presence of this phosphorus which accelerates char formation.