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Toxicological information

Toxicity to reproduction

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Administrative data

Endpoint:
screening for reproductive / developmental toxicity
Remarks:
based on test type (migrated information)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report date:
2012

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
GLP compliance:
yes (incl. QA statement)
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
O-isopropyl ethylthiocarbamate
EC Number:
205-517-7
EC Name:
O-isopropyl ethylthiocarbamate
Cas Number:
141-98-0
Molecular formula:
C6H13NOS
IUPAC Name:
O-isopropyl ethylthiocarbamate
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): IPETC
- Physical state: liquid
- Stability under test conditions: stable
- Storage condition of test material: ambient

Test animals

Species:
rat
Strain:
other: Crl: CD(SD)
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Charles River Laboratories,Research Models and Services, Germany GmbH, Sandhofer Weg 7, 97633 Sulzfeld, Germany
- Age at study initiation: Males/females: Both 57 days
- Weight at study initiation: 163 - 209 g
- Fasting period before study: 16 hours
- Housing: kept individually in MAKROLON cages (type III plus)
- Diet (e.g. ad libitum): Commercial ssniff® R/M-H V1534 (ssniff Spezialdiäten GmbH, 59494 Soest, Germany; served as food ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C ± 3°C
- Humidity (%): 55% ± 15%
- Air changes (per hr):
- Photoperiod (hrs dark / hrs light): 12 hours light / 12 hours dark

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
corn oil
Details on exposure:
VEHICLE
- Amount of vehicle (if gavage): 10 ml/kg b.w./day
Details on mating procedure:
Sexually mature male and female rats were randomly paired for mating. Mating
was monogamous: 1 male and 1 female animal were placed in one cage during the
dark period. The female was placed with the same male until pregnancy had occurred
or 2 weeks had elapsed. Each morning the females were examined for the
presence of sperm or a vaginal plug. If findings were negative, mating was repeated.
The day of conception (day 0 of gestation) was considered to be the day
on which sperm was found. In case pairing was unsuccessful, re-mating of females
with proven males of the same group was considered. This procedure was
repeated until at least 8 pregnant dams were available for each group.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
For the analysis of the test item-vehicle mixtures samples of approx. 2 x 1 mL
were taken at the following time points and stored at ≤ minus 20°C until analysis
at LPT:
Start of treatment period Concentration and stability
Immediately after preparation of the test itemvehicle
mixtures as well as 8 and 24 hours after
storage of the test item preparations at room
temperature:
3 samples/dose level group (groups 2 to 4)
Number of samples: 3 x 3 = 9
Homogeneity
At start of administration, during (middle) administration
and before administration to the
last animal of each dose level group:
3 samples/dose level group (groups 2 to 4).
Number of samples: 3 x 3 = 9
End of treatment period Concentration
During treatment with the test item always before
administration to the last animal/dose level
group:
1 sample/dose level group (groups 2 to 4).
Number of samples: TD 26 (1 x 3) = 3
Number of samples: TD 39 (1 x 3) = 3
Sum of all samples: 24
Sum of all aliquots: 48
The samples were labelled with the study number, test item, test species, type of
sample, aliquot number, concentration, test day, sampling time and date.
Duration of treatment / exposure:
Males
The daily administration of the test item started
two weeks before mating and lasted until the
day before sacrifice (considering a minimum total
dosing period of at least 28 days).
Females
The daily administration of the test item started
two weeks before mating and lasted up to at
least day 3 of lactation.
Frequency of treatment:
once daily
Details on study schedule:

- Age at mating of the mated animals in the study:10-11 weeks
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
31 mg/kg bodyweight/day
Basis:
actual ingested
Remarks:
Doses / Concentrations:
103 mg/kg bodyweight/day
Basis:
actual ingested
Remarks:
Doses / Concentrations:
309 mg/kg bodyweight/day
Basis:
actual ingested
No. of animals per sex per dose:
80 animals (40 male and 40 female rats),
10 animals/sex/group.
A sufficient number to grant at least 8 pregnant
females per group for evaluation of the F0 generation
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: See supporting study: 14-DAY DOSE-RANGE-FINDING STUDY OF IPETC (DANAFLOATTM 262) BY ORAL ADMINISTRATION TO RATS

Examinations

Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: at least daily, The frequency was increased when signs of toxicity were observed.
Cageside observations included skin/fur, eyes, mucous membranes, respiratory
and circulatory systems, somatomotor activity and behaviour patterns. The
onset, intensity and duration of any signs observed were recorded.
Individual animals were observed before and after dosing at each time of dosing for
any signs of behavioural changes, reaction to treatment or illness.
In addition, animals were checked regularly throughout the working day from 7:00
a.m. to 3:45 p.m. On Saturdays and Sundays animals were checked regularly from
7:00 a.m. to 11:00 a.m. with a final check performed at approximately 3:30 p.m.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at least daily, The frequency was increased when signs of toxicity were observed.
Additionally, once before the first exposure (to allow within-subject comparisons)
and once a week thereafter, detailed clinical observations were made in all animals
outside the home cage in a standard arena and at the same time, each time preferably
by observers unaware of the treatment. Signs noted included changes in
skin, fur, eyes, mucous membranes, occurrence of secretions and excretions and
autonomic activity (e.g. lacrimation, piloerection, pupil size, and unusual respiratory
pattern). Changes in gait, posture and response to handling as well as the
presence of clonic or tonic movements, stereotypies (e.g. excessive grooming,
repetitive circling), difficult or prolonged parturition or bizarre behaviour (e.g. selfmutilation,
walking backwards) were also recorded.
Dated and signed records of appearance, change, and disappearance of clinical
signs were maintained on clinical history sheets for individual animals.

BODY WEIGHT: Yes
- Time schedule for examinations: Males and females were weighed on the first day of dosing, weekly thereafter and
at termination of the study. During gestation, females were weighed on days 0, 7,
14 and 20 and within 24 hours of parturition (day 1 post-partum) and day 4 postpartum.
Body weights were recorded individually for each adult animal.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: daily

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
7.1.2 Clinical signs

Daily observations

Males: Pre-mating, mating and post-mating period
None of the male animals treated with 31 mg IPETC)/kg
b.w./day revealed any test item-related signs of systemic toxicity.
Treatment with 103 mg IPETC/kg b.w./day caused reduced
motility in all 10 male rats on each day of the first week of the pre-mating period,
starting between 5 and 20 minutes after administration and lasting for 2 to 6
hours. This symptom was of moderate degree on test days 1 to 4 and of slight
degree on test days 5 to 7. Furthermore, slightly reduced motility was observed in
one male (no. 48) on three days (test days 15 to 17) during the mating period.
In addition, increased salivation was observed in one male animal (no. 47) on test
days 13 and 14 (moderate degree) during the pre-mating period, on test days 17
and 18 (slight degree) and on test days 39 to 42 (moderate degree) during the
mating and post-mating period. This symptom started within 5 minutes after administration
and lasted for 20 to 60 minutes.
At 309 mg IPETC /kg b.w./day, prone position was seen in
all high dose males during test days 1 to 3 (pre-mating period). This symptom was
observed on one day (1 of 10 males), two days (3 of 10 males) or three days (6 of
10 males), starting within 5 to 20 minutes after administration and predominantly
lasting for 6 to 24 hours.

Furthermore, reduced motility was daily noted in all high dose male rats from day
3 or 4 onwards until day 21 or 22, starting within 5 to 60 minutes after administration
and lasting for 20 minutes up to 6 hours. This symptom was of moderate
degree on test days 3 and/or 4, and of slight degree from test day 5 onwards.
In addition, increased intake of drinking water and increased salivation were noted
in all high dose male animals on several to all test days from test day 7 to 12 onwards
until end of test on test day 43. Salivation started immediately to 20 minutes
after administration and lasted for 20 to 60 minutes, being of slight or moderate
degree, extremely increased salivation was noted in animal no. 68 on test
days 15 to 18. Piloerection was only noted in one male animal (no. 65) on test
day 1.

Females: Pre-mating and mating period
None of the female animals treated with 31 mg IPETC /kg
b.w./day revealed any test item-related signs of systemic toxicity.
Treatment with 103 mg IPETC /kg b.w./day caused reduced
motility in all female rats on test days 1 to 7 of the pre-mating period, starting between
5 and 20 min after administration and lasting for 2 to 6 hours. This symptom
was of moderate degree on test days 1 to 4 and of slight degree on test days
5 to 7.
In addition, piloerection was observed in one intermediate dose female animal (no.
57) on test day 1. Furthermore, slightly increased salivation was observed in one
intermediate dose female animal (no. 59) on test days 16 to 18 (mating period),
starting within 5 minutes after administration and lasting for 20 to 60 minutes.
At 309 mg IPETC /kg b.w./day, prone position was seen in
all high dose females during test days 1 to 4 of the pre-mating period. This symptom
was observed on all 4 days in the 9 surviving females and on 2 days before
premature death of female no. 79 on test day 3. Prone position started within 5 to
20 minutes after administration and lasted for up to 6 or up to 24 hours.
In addition, piloerection was observed in 7 of 9 surviving high dose female rats
(nos. 71, 72, 73, 74, 76, 77 and 80) from test day 1, 2, 3 or 8 onwards. This
symptom was noted on one to several test days of the pre-mating period and in
one female (no. 72) for totally 16 test days during the pre-mating and mating period.
Furthermore, reduced motility was noted in all surviving high dose female rats
daily from day 5 onwards until mating, starting within 5 to 20 minutes after administration
and lasting for 1 to 6 hours and for up to 24 hours on individual test
days. This symptom was of predominantly of slight degree, sometimes of moderate degree.
In addition, increased intake of drinking water was noted in 5 high dose females
(nos. 71, 73, 76, 77 and 78) during the pre-mating and/or mating period.
Apart from the afore-mentioned findings, the following clinical symptoms were
only noted in one high dose female (no. 72): haemorrhagic left eye (test days 8 to
10), pultaceous faeces (test day 10), decreased intake of drinking water (test days
10 to 13) and slightly or moderately increased salivation (several days during the
mating period), salivation starting immediately to 20 minutes after administration
and lasting for 20 to 60 minutes.
Females: Gestation period
None of the female animals treated with 31 mg IPETC /kg
b.w./day revealed any test item-related signs of systemic toxicity during the gestation
period.
At 103 mg IPETC /kg b.w./day, slightly or moderately increased
salivation was still noted in one female (no. 59) on a few days and in one
female (no. 58) on one day of the gestation period, starting immediately to 20
minutes after administration and lasting for 20 to 60 minutes. A haemorrhagic vagina
was noted in one intermediate dose female (no. 51) on gestation day 17.
At 309 mg IPETC /kg b.w./day, slightly reduced motility was
still noted in 7 of 9 females on 3 to 8 test days of the gestation period (days 0 to
8) starting within 5 to 20 minutes after administration and lasting for 1 to 6 hours
and for up to 24 hours on individual test days.
In addition, slightly increased salivation was noted in 6 high dose females (nos.
71, 72, 73, 74, 76 and 78) on one to several days of the gestation period, starting
immediately to 20 minutes after administration and lasting for 20 to 60 minutes.
Increased intake of drinking water was noted in 5 high dose females (nos. 71, 72,
76, 77 and 78) on several to all gestation days.
One high dose female (no. 78) revealed piloerection on 2 days of the gestation
period.

Females: Lactation period
Piloerection was noted in 2 of 10 dams (nos. 36 and 38) treated with 31 mg
IPETC /kg b.w./day on 1 or 2 days during the lactation period.
At 103 mg IPETC /kg b.w./day, only 3 of 10 dams littered as
a total post-implantation loss was noted in the remaining 7 dams. None of these 3
female animals revealed any test item-related signs of systemic toxicity during the
lactation period.
No lactation period was determined for the high dose level as administration of
309 mg IPETC /kg b.w./day caused a total post-implantation
loss in all treated dams.
Dermal irritation (if dermal study):
not specified
Mortality:
mortality observed, treatment-related
Description (incidence):
Males
No deaths were noted in the male rats treated with 31, 103 or 309 mg IPETC /kg b.w./day.
Females
No deaths occurred during treatment of the female rats with 31, 103 or 309 mg
IPETC /kg b.w./day except for one high dose dam (no. 79)
which was found dead on test day 3. Prone position was observed on the days
before death, necropsy revealed gastric lesions. The death of this animal is considered
as test item-related.
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Male animals: Pre-mating, mating and post-mating period
No test item-related influence was noted on the body weight or the body weight
gain of the male animals treated with 31 mg IPETC kg
b.w./day during the pre-mating, mating and post-mating period. The mean body
weight gain from the start of treatment (test day 1) was plus 76.0% (control: plus
76.2%) at the end of treatment (test day 43).
At 103 mg IPETC kg b.w./day, a marginal, not statistically
significant reduction in body weight (5% below the control value) was noted at
the end of the study on test day 43. The mean body weight gain from the start of
treatment (test day 1) was plus 67.0% (control: plus 76.2%) at the end of treatment
(test day 43). The differences are regarded to be spontaneous.
The body weight of the high dose males (309 mg IPETC kg
b.w./day) was reduced from test day 8 until end of the study on test day 43
(p ≤ 0.01), being approx. 9 to 12% below the control values. Body weight and
body weight gain were statistically significantly (p ≤ 0.01) reduced on test days
8, 15, 22, 29, 36 and 43. The mean body weight gain from the start of treatment
(test day 1) was plus 55.3% (control: plus 76.2%) at the end of treatment (test
day 43).

Female animals: pre-mating period
No test item-related influence was noted on the mean body weight and the body
weight gain during the pre-mating period (test day 1 to test day 15) at the low
dose level (31 mg IPETC /kg b.w./day). The mean body
weight gain from the start of treatment (test day 1) was plus 8.4%, respectively
(control: plus 10.0%) at the end of the pre-mating period (test day 15).
At 103 mg IPETC /kg b.w./day, slight reductions were noted
for the body weight (up to 7% below the control values) during pre-mating period.
Statistically significant reductions compared to the control were noted in the first
test week for the body weight (at p ≤ 0.05) and the body weight gain (at
p ≤ 0.01). The mean body weight gain from the start of treatment (test day 1)
was plus 3.1% (control: plus 10.0%) at the end of the pre-mating period (test day
15).
Statistically significant reductions at p ≤ 0.01 were noted for the body weight of
the high dose females (309 mg IPETC /kg b.w./day) during
the first and second test week of the pre-mating period (up to 12% below the control
values). Statistically significant reductions compared to the control (at
p ≤ 0.01) were accordingly noted for the body weight gain. A negative body
weight gain (3.9%, control: plus 10.0%) was noted from the start of treatment
(test day 1) until end of the pre-mating period (test day 15).
Female animals: gestation period
No test item-related influence was noted on the body weight and body weight gain
of the female animals treated with 31 mg IPETC /kg b.w./day
during the gestation period. The increase in the mean body weight from day 0 of
gestation until day 20 was plus 54.0% (control: plus 59.4%).
At 103 mg IPETC /kg b.w./day, statistically significant reductions
(at p ≤ 0.01) were noted for the body weight on gestation days 14 and 20
(up to 26.4% below the control values). The body weight gain was accordingly
reduced (significant at p ≤ 0.01). The mean body weight gain from the start of
treatment (test day 1) was only plus 18.9% (control: plus 59.4%) on gestation
day 20.
At 309 mg IPETC /kg b.w./day, statistically significant reductions
(at p ≤ 0.01) were noted for the body weight on gestation days 7, 14 and
20 (up to 33.3% below the control values). The body weight gain was significantly
reduced (at p ≤ 0.05 or p ≤ 0.01) on gestation days 7, 14 and 20. The
mean body weight gain from the start of treatment (test day 1) was only plus
12.8% (control: plus 59.4%) on gestation day 20.
The absence of the expected body weight increase during the gestation period
was obviously due to the high incidences of total post-implantation loss precluding
the typical body weight increase during pregnancy at 103 mg IPETC
/ kg b.w./day (7 of 10 females were affected) and 309 mg
IPETC /kg b.w./day (all 9 surviving females were affected).

Female animals: lactation period
No test item-related influence was noted on the body weight and body weight gain
of the females treated with 31 mg IPETC / kg b.w./day (10
littering dams) or with 103 mg IPETC /kg b.w./day (3 littering
dams) during the lactation period.
No body weight was recorded for the high dose females during the lactation period
as none of these dams littered due to a total post-implantation loss,
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
Males: pre-mating period
No test item-related effect on food consumption was noted in the male rats
treated with 31 or 103 mg IPETC /kg b.w./day during the
pre-mating period.
At 309 mg IPETC /kg b.w./day, a statistically significant reduction
(p ≤ 0.01) by 15.4% compared to the control was noted for the relative
food intake of the male rats in the first test week of the pre-mating period. The
relative food intake was statistically significantly increased (at p ≤ 0.01) compared
to the control in the second test week. This increase has to be assessed by
considering the reduced body weight noted for the high dose males at this time
as the absolute food consumption was not increased.

No food intake of female animals was recorded during the mating period as both
sexes were housed together.

Females: gestation period
No test item-related influence on food consumption was found in the female rats
after treatment with 31 or 103 mg IPETC /kg b.w./day during
the gestation period.
At 309 mg IPETC /kg b.w./day, the relative food intake was
marginally reduced (up to 11.6% below the control) during the gestation period.
Females: lactation period
At 31 or 103 mg IPETC /kg b.w./day, the relative food intake
was marginally reduced (14.7% below the control for the low dose group and
5.9% below the control for the intermediate dose group) during the lactation period.
No food intake was recorded for the high dose females during the lactation period
as none of these dams littered due to a total post-implantation loss.
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not examined
Haematological findings:
effects observed, non-treatment-related
Description (incidence and severity):
Male and female animals:
No test item-related influence was noted in the haematological parameters examined
at the end of the pre-mating period (test day 15) of male and female rats
treated with 31, 103 or 309 mg IPETC /kg b.w./day.
No test item-related influence was noted for the haemoglobin content, the number
of erythrocytes, leucocytes, reticulocytes and platelets, the haematocrit value, the
thromboplastin time and the activated partial thromboplastin time, the mean corpuscular
volume (MCV), the mean corpuscular haemoglobin (MCH) and the mean
corpuscular haemoglobin concentration (MCHC) compared to the control. No test
item-related changes were noted in the relative and absolute differential blood
count.
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
Male and female animals:
No test item-related changes were noted on biochemical parameters on test day
15 for male and female rats treated with 31 or 103 mg IPETC /kg b.w./day compared to the control.
This includes also the serum level of bile acids of the male rats of the low and intermediate
groups except for one outlier in the low dose group. Bile acids are
known to show a high inter-individual variability. In addition, the sampling size of
n = 5 animals per sex is fairly small (see table below).
At 309 mg IPETC /kg b.w./day, test item-related and statistically
significantly (p≤0.01) increased mean values were obtained for the plasma
levels of cholesterol (total) of the male (by 26%) and female (by 68%) rats and for
the serum levels of the bile acids (by 984%) of the male rats.
Urinalysis findings:
not specified
Behaviour (functional findings):
not specified
Immunological findings:
not specified
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
not specified
Histopathological findings: neoplastic:
not specified
Other effects:
not specified

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
not specified
Reproductive function: sperm measures:
not specified
Reproductive performance:
effects observed, treatment-related
Description (incidence and severity):
Examination of gestation length
Note: The calculation of the gestation length includes the day of positive sperm
detection (mating day or gestation day 0) and the day/s of littering. The
day, on which there was no sign of littering anymore in the morning is defined
as litter day 1 and is not part of the gestation period anymore.
No test item-related influence was noted on the gestation length of the females
treated with 31 mg IPETC /kg b.w./day compared to the control
group.
A total post-implantation loss was noted in 7 of 10 females treated with 103 mg
IPETC /kg b.w./day. The gestation length of the remaining
3 females was within the normal range.
No data on gestation length were available for the high dose dams (treated with
309 mg IPETC /kg b.w./day) as a total post-implantation loss
was noted in all 9 surviving dams.

Evaluation of reproduction parameters of F0 dams
Corpora lutea and implantation sites
No statistically significant differences were noted in the number of corpora lutea or
implantation sites between the control and the treatment groups (31, 103 or
309 mg IPETC /kg b.w./day).
No test item-related increases were noted for the pre-implantation loss at any
tested dose level.
Number of pups
No female aborted. No runts or malformed pups were noted at birth.
At 31 mg IPETC /kg b.w./day, the number of born pups (alive
and dead) was within the normal range.
However, statistically significant reductions (at p ≤ 0.01) were noted for the birth
index (calculated from the total number of born pups and the total number of implantation
sites), being 76% (control: 97%).
This reduction in the birth index was considered as test item-related.
The live birth index was slightly reduced to 95.9% in comparison to the control
with 99.2%. This slight reduction was considered as not test item-related. In detail, the number of pups born alive was only marginally reduced due to the incidence
of 5 stillbirths. Stillbirths were noted in dam no. 32 (two stillbirths) and in
dam no. 39 (three stillbirths). One stillbirth was noted in the control group (dam
no. 19).
The gestation index of 90% (control: 100%) was still within the range of LPT
background data (see table below). No living pups, only two stillbirths were noted
in one of 10 litters (dam no. 32).
A statistically significant increase (at p ≤ 0.01) was noted for the postimplantation
loss (26.9%, control: 3.6%; for LPT background data see table below),
which was considered as test item-related.
At 103 mg IPETC /kg b.w./day), a statistically significant
increase (at p ≤ 0.01) was noted for the post-implantation loss (96.4%, control:
3.6%) caused by a complete loss of implants in 7 of 10 examined females.
Statistically significant reductions (at p ≤ 0.01) were noted for the gestation index
(30%, control: 100%), the birth index (4%, control: 97%), the number of born
pups (alive and dead) and the number of live born pups.
In total, only 5 pups (all of them live-born) were found in 3 examined litters: one
pup each in the litter of dams no. 52 and 53, and 3 pups in the litter of dam no.
56. Hence, a live birth index of 100% was calculated (control: 99.2%; for LPT
background data see table below).
No data on pups were available for the high dose dams (treated with 309 mg
IPETC /kg b.w./day) as a total post-implantation loss was
noted in all 9 surviving dams (post-implantation loss: 100%, control: 3.6%). Statistically
significant reductions (at p ≤ 0.01) were noted for the gestation index
(0%, control: 100%) and the birth index (0%, control: 97%;

Effect levels (P0)

open allclose all
Key result
Dose descriptor:
NOAEL
Effect level:
31 mg/kg bw/day (nominal)
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
clinical signs
mortality
body weight and weight gain
Key result
Dose descriptor:
NOAEL
Remarks:
for effects on reproductive toxicity
Effect level:
< 31 mg/kg bw/day (nominal)
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
other: Effects on reproductive toxicity NOAEL (no-observed-adverse-effect level): below 30 mg/kg b.w./day

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:
not specified
Dermal irritation (if dermal study):
not examined
Mortality:
not examined
Body weight and weight changes:
not examined
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
not examined
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Other effects:
not examined

Reproductive function / performance (P1)

Reproductive function: oestrous cycle:
not examined
Reproductive function: sperm measures:
not examined
Reproductive performance:
not examined

Effect levels (P1)

Remarks on result:
not measured/tested

Results: F1 generation

General toxicity (F1)

Clinical signs:
not specified
Dermal irritation (if dermal study):
not examined
Mortality / viability:
mortality observed, treatment-related
Description (incidence and severity):
No statistically significant differences were noted between the survival index (viability
index) of the control group and the low and intermediate dose groups (31 or
103 mg IPETC /kg b.w./day).
One stillbirth was noted in the control group (dam no. 19). Three control pups
from two different dams (nos. 16 and 19) were cannibalised on lactation day 3 or
4, leading to a mean survival index of 98.0%, hence, no effect was observed.
In the low dose group (31 mg IPETC /kg b.w./day), five stillbirths
were noted. No living pups, only two stillbirths were noted in one of 10 litters
(dam no. 32). Three stillbirths were found in the litter of dam no. 39. In addition,
two pups from two dams (nos. 34 and 39) were cannibalised on lactation
day 3 or 4, leading to a total viability index of 98.3% (control: 97.7%).
In the intermediate dose group (103 mg IPETC /kg b.w./day),
only 5 pups (all of them live-born) were found in 3 examined litters. One pup (dam
no. 53) was found dead one day after birth, leading to a total viability index of
80% (control: 97.7%) and a mean viability index of 66.7% (98.0%) on gestation
day 4. A second pup (dam no. 52) was found dead before sacrifice on lactation
day 5.
No data on pups were available for the high dose dams (treated with 309 mg
IPETC /kg b.w./day) as a total post-implantation loss was
noted in all 9 surviving dams
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
Mean litter weight
At 31 mg IPETC /kg b.w./day, a slight - not statistically significant
- reduction in mean litter weight was noted on lactation day 1 for male
pups, female pups and total pups (approx. 6% below the control value). On lactation
day 4, the mean litter weight was within the range of the control.
In the intermediate dose group (103 mg IPETC /kg b.w./day),
normal weights were for the mean litter weight on lactation day 1 calculated for
only five pups available in this group. Reduced mean litter weights - not statistically
significant compared to the control - were calculated on lactation day 4 for
the two male pups (approx. 16% below the control) and for the total of four surviving
pups. This finding was due to the reduced body weight noted for the single
male pup of dam no. 52.
Total litter weight
No statistically significant differences were noted between the total litter weight of
the pups at 31 mg IPETC /kg b.w./day or the control pups.
A statistically significant reduction (at p ≤ 0.01) in total litter weight was noted
for the intermediate dose group (103 mg IPETC /kg b.w./day)
on lactation days 1 and 4 (male and total pups). Due to the low incidence of only
2 female pups no statistical comparison could be carried out for the female pups.
No data on mean or total litter weights were available for the high dose dams
(treated with 309 mg IPETC /kg b.w./day) as a total postimplantation
loss was noted in all 9 surviving dams.
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Sexual maturation:
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
not examined
Histopathological findings:
not examined
Other effects:
not examined

Developmental neurotoxicity (F1)

Behaviour (functional findings):
not examined

Developmental immunotoxicity (F1)

Developmental immunotoxicity:
not examined

Effect levels (F1)

Key result
Dose descriptor:
LOAEL
Generation:
F1
Effect level:
ca. 31 mg/L air (nominal)
Based on:
act. ingr.
Sex:
male/female
Basis for effect level:
viability
mortality
body weight and weight gain

Results: F2 generation

General toxicity (F2)

Clinical signs:
not examined
Dermal irritation (if dermal study):
not examined
Mortality / viability:
not examined
Body weight and weight changes:
not examined
Food consumption and compound intake (if feeding study):
not examined
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Sexual maturation:
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
not examined
Histopathological findings:
not examined
Other effects:
not examined

Developmental neurotoxicity (F2)

Behaviour (functional findings):
not examined

Developmental immunotoxicity (F2)

Developmental immunotoxicity:
not examined

Effect levels (F2)

Remarks on result:
not measured/tested

Overall reproductive toxicity

Reproductive effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
Treatment with IPETC produced significant post-implantation loss (early abortions), with a very steep dose-response. Grp mean values were: 3.6% (control), 26.9%, 96.4%, and 100%.
Based on the (limited) investigations in this screening study,
the effect appear to be very specific,
And did not correlate with parental toxicity.
Therefore, IPETC appear to be a developmental toxicant.
No NOAEL for the offspring could be established from this study, but it can be concluded that it lies below 31 mg/kg bw./day, which is this studies LOAEL.