Environmental Profiles of Chemical Flame-Retardant Alternatives for

Critical Studies
Type: Delayed neurotoxicity
Species, strain, sex, number: Hen, White Leghorn, 9 for TPP
Purity: Not reported, prepared from pure phenol
Doses: 5,000 mg/kg twice daily; thus, 10,000 mg/kg/day
Vehicle: Corn oil
Route: Gavage
Exposure duration, frequency: Twice a day on days 1-3 and 21-23 of the study (6 days of
dosing); interval between doses not reported.
Method: Dosing twice daily for 6 days was needed because of the low toxicity of TPP (no
lethality at 5 mg/kg, the largest feasible dose). Hens were fasted for 16 hours before dosing
(further explanation not provided). Daily observations for deaths and signs of neurotoxicity
were conducted from day 1 through day 42, at which time hens were necropsied. Brain, sciatic
nerve, and spinal cord were examined histopathologically. Tricresyl phosphate (mixed o-, m-,
p-) was tested concurrently.
Results: For TPP, no overt signs of neurotoxicity and no histopathological effects in the nervous
tissues were observed (0/9). Although the hens were weighed at 0, 21, and 42 days, no body
weight results were presented. Tricresyl phosphate, a known delayed neurotoxicant, resulted in
overt signs and histopathological evidence of delayed neurotoxicity in 6/6. Details of the
histopathological data were not provided.
Reference: Johannsen et al., 1977
Type: Delayed neurotoxicity
Species, strain, sex, number: Hen, Rhode Island Red x Light Sussex, 2/dose
Purity: Not reported, white flakes
Doses: 2,000, 3,000, 5,000, 8,000, or 12,500 mg/kg
Vehicle: Arachis oil
Route: Gavage
Exposure duration, frequency: Single dose
Method: Hens were not fasted. Post-dosing observation period was 21 days. Daily observations
for deaths and signs of neurotoxicity. Necropsy but not histopathology.
Results: No overt signs of neurotoxicity. Necropsy results not mentioned.
Reference: Ciba-Geigy Pharmaceuticals Division, 1980
Type: Delayed neurotoxicity
Species, strain, sex, number: Hen, Rhode Island Red x Light Sussex, 2
Purity: Not reported, white flakes
Doses: 12,000 mg/kg
Vehicle: Arachis oil
Route: Gavage
Exposure duration, frequency: Single dose
Method: Hens were not fasted. Post-dosing observation period was 21 days. Daily observations
for deaths and signs of neurotoxicity. Necropsy but not histopathology.
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