Evaluation of Toxic Potency Values for Smoke From Products and Materials.
Evaluation of Toxic Potency Values for Smoke From
Products and Materials.
Neviaser, J. L.; Gann, R. G.
Fire Technology, Vol. 40, No. 2, 177-199, April 2004.
smoke; toxicity; evaluation; incapacitation; test
methods; toxicity; LC50; combustion; flaming combustion
Many devices have been used to generate data on the
toxic potency of smoke from burning products and
materials. This paper critically reviews those apparatus
and sorts them by the combustion conditions (related to
a type of fire) producing the smoke, the specimens
tested, and the animal effect measured. All the usable
data were derived using rats, and the toxicological
effects encountered were lethality, represented by an
LC50value, and incapacitation, expressed as an IC50
value. The data showed a wide range of toxic potency
values for the products and materials tested. For those
engineering applications where the mix of combustibles
is unknown, generic values of smoke toxic potency were
derived. Statistical analysis of the wealth of published
data yielded a generic LC50 value of 30 g/m3 - 20 g/m3
(one standard deviation) for 30 minute exposure of rats
for smoke from well-ventilated combustion. There are
limited data for underventilated combustion, and a value
of 15 g/m3 - 5 g/m3 is suggested. The mean value of the
ratios of IC50 values to LC50 values is 0.50 - 0.21,
consistent with a prior review. Thus, for
well-ventilated fires, a generic 30 minute IC50 value
(for rats) would be 15 g/m3 - 10 g/m3; for
underventilated fires, the corresponding number would be
7 g/m3 - 2 g/m3. There are some materials with
appreciably lower potency values, indicating higher
smoke toxicity. If materials like these are expected to
comprise a large fraction of the fuel load, a lower
generic value should be used.