Use of this information is subject to copyright laws and may require the permission of the owner of the information, as described in the ECHA Legal Notice.
EC number: 603-094-7
CAS number: 125904-11-2
In a two-generation study, groups of 35 male
and female Sprague-Dawley rats were treated daily, by oral gavage, at
dosages of 100, 400 and 1600 mg/kg bw/day. A concurrent vehicle control
group received Mazola corn oil at 5 mL/kg bw. The F0 parent animals were
treated for at least 70 days prior to mating. Treatment continued
throughout all subsequent phases of the study until one day prior to the
scheduled necropsy for each animal. All females were allowed to deliver
and rear their pups to weaning (lactation day 21, culling performed on
lactation day 4). One litter was produced in each generation. Offspring
from the F0 animals (F1 litters) were selected to constitute the F1
generation. The study design for the F1 generation was identical to the
F0 generation; 35 animals per sex were selected for each dose group.
Beginning day 22 post partum, the selcted F1 parent animals were treated
for at least 70 days prior to the pairing and throughout all subsequent
phases of the study until one day prior to the scheduled necropsy for
Decreased male fertility in the F1
generation at 1600 mg/kg bw/day was considered to be a potential effect
of dibromostyrene administration. Although no morphological changes were
observed in the reproductive tract of these males, the mean absolute
testes weight was signficantly reduced. Other reproductive parameters
(gestation length and parturition) were unaffected by treatment in the
F0 and F1 generations at any dose level.
Survival was affected at 1600 mg/kg bw/day;
17 F0 animals (3 males and 14 females) and 2 F1 females died or were
euthanised moribund. Nine of these F0 females died due to an apparent
enhanced toxicity of the test substance due to water deprivation on one
day. Treatment-related clincial signs (primarily salivation, clear
staining around the mouth and/or yellow staining in the urogenital area)
occurred in the F0 and F1 animals at 400 and 1600 mg/kg bw/day. Body
weight gain and/or food cinsumption were inhibited in the 400 mg/kg
bw/day males (F0 and F1 during the 1st week of dosing), 1600 mg/kg
bw/day males (F0 and F1 primarily during the initial one to four weeks
of dosing) and 1600 mg/kg bw/day females (F1 at the end of the gestation
and during the lactation period).
No tretment-related internal findings were
observed in the F0 and F1 parent animals that survived to the scheduled
necropsies. Increased liver weights were apparent in the F0 and F1
generations at 400 and 1600 mg/kg bw/day. Increased weights and
treatment-related microscopic lesions were observed in the kidney at
1600 mg/kg bw/day (F0 and F1); the microscopic lesions consited of
tubular dilatation, nephrosis and/or papillary necrosis. Increased
kidney weights, but no microscopic lesions, were also noted in males at
400 mg/kg bw/day (F0 and F1).
In the F1 and F2 neonates, adverese effects
were apparent at 400 and 1600 mg/kg bw/day. Live litter sizes were
slightly decreased (non-significant) in the 400 mg/kg bw/day F1 pups and
the 1600 mg/kg bw/day F1 and F2 pups. Pup viability was reduced at 400
mg/kg bw/day (F2) and 1600 mg/kg bw/day (F1 and F2). Changes in clinical
condition of the pups (primarily body cool to the touch) were observed
in both generations at 400 and 1600 mg/kg bw/day. Neonatal body weights
were reduced at 400 mg/kg bw/day beginning days 28 (F1) or 21 (F2) post
partum and at 1600 mg/kg bw/day beginning day 1 post partum (F1 and F2).
At 100 mg/kg bw/day, kidney and liver
weights were increased in the F1 males. No other adverse effects were
apparent on the F0, F1 or F2 animals.
The NOAEL for reproductive toxicity was 400
mg/kg bw/day. The NOAEL for neonatal toxicity was 100 mg/kg bw/day. The
NOAEL for parental systemic toxicity was 100 mg/kg bw/day for the F0
generation, and less than 100 mg/kg bw/day for the F1 generation.
Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number does however not guarantee that the information in the dossier is correct or that the dossier is compliant with Regulation (EC) No 1907/2006 (the REACH Regulation). This information has not been reviewed or verified by the Agency or any other authority. The content is subject to change without prior notice.Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
På den här webbplatsen används kakor. Syftet är att optimera din upplevelse av den.
Welcome to the ECHA website. This site is not fully supported in Internet Explorer 7 (and earlier versions). Please upgrade your Internet Explorer to a newer version.
Do not show this message again