Special-needs groups, fire

A further factor considered by the Special Working Group meeting was the need to apply additional limits for materials whose physical properties might render invalid the assumptions used in deriving the Q values discussed above. Such considerations are relevant to materials that may become volatile at the elevated temperatures which could occur in a fire, or which may be transported as very finely divided powders, and especially for the model used to evaluate the values. However, on balance it was considered that only in the most extreme circumstances would the assumed intake factor of 10 be exceeded and that special modification of the Qf. model was unnecessary for these materials. 

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