Specification

MATERIAL SAFETY DATA
SHEET
Version: 1.6
07/16/2012
GE5100
Silicone Rubber Sealant
Page 6/9
OTHER
Octamethylcyclotetrasiloxane
Ingestion: Rodents given large doses via oral gavages of Octamethylcyclotetrasiloxane (1600 mg/kg
day, 14 days) developed increased liver weights relative to unexposed control animals due to
hepatocellular hyperplasia (increased number of liver cells which appear normal) as well as hypertrophy
(increased cell size).
Inhalation: In inhalation studies, laboratory rodents exposed to Octamethylcyclotetrasiloxane (300 ppm
five days week, 90 days) developed increased liver weights in female animals relative to unexposed
control animals. When the exposure was stopped, liver weights returned to normal. Microscopic
examination of the liver cells did not show any evidence of pathology. Inhalation studies utilizing
laboratory rabbits and guinea pigs showed no effects on liver weights. Inhalation exposures typical of
industrial usage (5-10 ppm) showed no toxic effects in rodents.
Range finding reproductive studies were conducted (whole body inhalation, 70 days prior to mating,
through mating, gestation and lactation) with Octamethylcyclotetrasiloxane (D4). Rats were exposed to
70 and 700 ppm. In the 700 ppm group, there was a statistically significant reduction in mean litter size
and in implantation sites. No D4 related clinical signs were observed in the pups and no exposure
related pathological findings were found.
Interim results from a two generation reproductive study in rats exposed to 500 and 700 ppm D4 (whole
body inhalation, 70 days prior to mating, through mating, gestation and lactation) resulted in a
statistically significant decrease in live mean litter size as well as extended periods of off-spring delivery
(dystocia). These results were not observed at the 70 and 300ppm dosing levels.
Preliminary results from an ongoing 24-month combined chronic/oncogenicity study in rats exposed to
10, 30, 150, or700 ppm D4 showed test-article related effects in the kidney (male and female) and uterus
of rats exposed for 12 to 24 months. These effects include increased kidney weight and severity of
chronic nephropathy, increased uterine weight, increased incidence of endometrial cell hyperplasia, and
an increased incidence of endometrial adenomas. All of these effects are limited to the 700 ppm
exposure group.
These results have been shown to be rat-specific. Further studies are ongoing.
In developmental toxicity studies, rats and rabbits were exposed to Octamethylcyclotetrasiloxane at
concentrations up to 700 ppm and 500 ppm respectively. No teratogenic effects (birth defects) were
observed in either study.
,Contains dibutyltin compound(s) - May impair fertility. May cause harm to unborn child.
GENETIC TOXICITY IN
VIVO
Test type: Dominant lethal assay; Rat; Result: negative
SENSITIZATION
No data available.
(or GE57)