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: 201-622-7
CAS number: 85-68-7
Table 1: Effect of phthalate esters
on uterine wet weight and vaginal cell cornification in ovariectomized
Body weight (g)
Uterine wet wt (mg)
Uterine wet wt
(mg/100 g body wt)
Number of positive smearsc
% Cornification of smearsd
*Statistically significant difference
from control atp< 0.05.
**Statistically significant difference
from control atp< 0.01.
animals were used per treatment group.
were ovariectomized on day 19. Dosing via oral gavage on days 31-34, and
the animals were euthanized on day 35.
ovariectomized (OVX) rats were dosed via oral gavage for four
consecutive days. Vaginal lavages were performed prior to dosing to
ensure that the animals were not cycling, on each day of dosing (days 1
to 4, inclusive) and 24 h after the last treatment (day 5) prior to
asphyxiation. The results in the table are from lavages collected on day
4. Results collected on days 1 to 3 and 5 were comparable. Note that
some groups had less then 10 animals due to premature death during the
of cornification of smears was calculated as described by Terenius
(1971). The results are a semiquantitative estimate of the percentage of
cornified cells relative to leucocytes. Two independent evaluators, both
blind to the treatment protocols,
were used to score the degree of cornification.
from animals used in experiment 2 found to possess ovarian stubs were
not included in the data set. The number in the parenthesis indicates
the number of animals used to determine the mean±standard
In a uterotrophic assay, groups of 10 ovariectomised immature rats were
dosed orally with benzylbutylphthalate at 20, 200 or 2000 mg/kg bw/day
for 4 days. Two further groups of 10 animals received sesame oil only
(vehicle control) and ethynyl oestradiol at 1 mg/kg bw/day (positive
control). Uterine weights were recorded at necropsy on the day after the
final dose, and mean absolute wet weight and wet weight relative to body
weight were calculated. The assay was performed twice (experiments 1 and
2). Groups of 10 ovariectomised mature rats were dosed similarly, and
vaginal lavages performed prior to dosing, on each day of dosing and on
the day after dosing. The number of positive smears and the proportion
of smears with vaginal cell cornification were recorded.
No reproducible effect on uterine weight or vaginal cell cornification
was detected in benzylbutylphthalate-treated rats, whereas ethynyl
oestradiol produced a strong positive response in both assays.
Three in vitro assays for oestrogenic activity were also performed.
These included an assay for competitive ligand-binding to rat uterine
oestrogen receptors, assessment of gene expression in recombinant
receptor/reporter gene assays in mammalian cells, and evaluation of
viability in an oestrogen-dependent strain of yeast. Weak oestrogenic
activity was detected in all three in vitro assays.
In two reliable in vivo assays in ovariectomised rats (uterotrophic and
vaginal cell cornification assays), no oestrogenic activity was detected
after oral dosing with benzylbutylphthalate at up to 2000 mg/kg bw/day.
Weak oestrogenic activity was detected in vitro.
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.
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