Long ago a scientist who did an early smoke study using many materials concluded to me in private that all smoke is bad, but he didn’t believe one was worse than another. This study was paid for by two fiber manufacturers and independently conducted by a respected industrial hygiene company to truly assess the off-gas of the major materials on the market. It concludes that all contain some gasses which are harmful, but it is unlikely any would cause harm from the gasses in a flash fire. Injury from breathed gasses would be from the thermal component to the lung tissue. This has been our experience in over 160 accidents we have been involved in investigating.
The burns to the lungs have been from the arc flash itself in one case, and two cases exhibited burns from flammable oil in the cable or transformer. Now sales of materials can be on the actual characteristics of the fabrics rather than raising false fears of the off-gasses or of the toxicity of the FR. All the best studies show that FR and AR materials are safe to wear and protective in flash fire and arc flash.
The study will be published in Fire Technology Journal February 2015