SDS
11. TOXICOLOGICAL INFORMATION (Continued)
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SKIN EFFECTS.......: Rabbit: Slight dermal irritant.
SENSITIZATION......: Guinea Pig: Not a dermal sensitizer.
SUBCHRONIC TOXICITY...: In a 3 week dermal toxicity study, cyfluthrin technical
was administered to rats for 6 hours/day at dose levels of 100, 340 or 1000
mg/kg. Animals received a total of 17-18 applications in a period of 22-23
days. An additional control and high-dose group were treated and maintained
for 14-15 days following treatment so as to ascertain the extent of recovery.
Effects observed included reduced feed consumption, red nasal discharge, urine
stains, and findings at the dose site (scabbing, crusty, discolored and raised
zones). Histologically, epidermal and dermal alterations in treated skin were
observed in animals of the mid- and high-dose groups. Similar, but slightly
less severe microscopic alterations were also observed in the high-dose
recovery group. The overall no-observable-effect-level (NOEL) was 100 mg/kg.
In a 13 week inhalation study, rats were exposed to cyfluthrin at aerosol
concentrations of 0.09, 0.71 or 4.51 mg/cubic meter for 6 hours/day, 5
days/week. The NOEL was 0.09 mg/cubic meter based on reduced body weight
gains.
CHRONIC TOXICITY......: Cyfluthrin has been investigated in chronic feeding
studies using two different strains of rats. In each study, cyfluthrin was
administered for 2 years at dietary concentrations ranging from 50 to 450 ppm.
Body weight gains were decreased at concentrations of 150 ppm and greater.
Changes in clinical chemistries occurred at 450 ppm. In one of the studies,
histopathology revealed a numerical increase in mammary gland adenocarcinomas
at 450 ppm. This finding was not statistically significant when compared to
the controls and is not considered to be compound-related. In each study, the
overall NOEL was 50 ppm based on decreased weight gains. In a 1 year feeding
study, dogs were administered cyfluthrin at dietary concentrations of 50, 100,
360 or 650 ppm. Beginning on week 8, the high-dose was reduced to 500 ppm for
the remainder of the study due to severe clinical neurological symptoms. Body
weights were decreased for animals of the high-dose. Neurological findings
(gait abnormalities and postural reaction deficits) were observed at doses of
360 and greater. The NOEL was 100 ppm.
CARCINOGENICITY.......: Cyfluthrin was investigated for carcinogenicity in
chronic studies using several different strains of rats and mice. In rats,
the maximum level tested was 450 ppm. Maximum levels tested in mice were 1400
and 1600 ppm for males and females, respectively. There was no evidence of a
carcinogenic potential observed in any of the strains in either species.
MUTAGENICITY..........: Numerous in vitro and in vivo mutagenicity studies have
been conducted on cyfluthrin, all of which are negative.
DEVELOPMENTAL TOXICITY: In developmental toxicity studies using rats,
cyfluthrin was administered during gestation by oral gavage at doses ranging
from 1 to 30 mg/kg. The overall NOEL from these studies for maternal toxicity
was 3 mg/kg. No developmental effects were observed at any of the doses
tested. In each study, the NOEL for developmental toxicity was equivalent to
the highest dose tested. The NOELs for developmental toxicity for the initial
study and the subsequent study were 30 and 10 mg/kg, respectively. Rabbits
were administered cyfluthrin during gestation by oral gavage at doses ranging
from 5 to 180 mg/kg. At maternally toxic levels, there was an increased
incidence of post-implantation losses. The overall NOEL derived from these
studies for both maternal and developmental toxicity was 20 mg/kg. In an
inhalation study, rats were exposed during gestation to cyfluthrin at aerosol
Product Code: 41741 MSDS Page 6
Approval date: 11/07/2001 Continued on next page