Dialkyl phosphinic acid

Toxicity to reproduction

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:

2013

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

(Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit, München, Germany)

Limit test:

no

Test material

Test material information

Constituent 1

Test material form:

solid: compact

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Test System

Species/strain: healthy Wistar rats, Crl: WI(Han) (Full Barrier)
Source: Charles River, 97633 Sulzfeld, Germany
Sex: male and female; the female animals were non-pregnant and nulliparous.
Age at the start of the treatment period: males: 10-11 weeks old, females: 10-11 weeks old.
Body weight at the allocation of the animals to the experimental groups:
males: 272 - 330 g (mean: 300.13 g, ± 20% = 240.10 – 360.15 g)
females: 180 - 218 g (mean: 200.90 g, ± 20% = 160.72 – 241.08 g)
The animals were derived from a controlled full-barrier maintained breeding system (SPF). According to Art. 9.2, No. 7 of the German Act on Animal Welfare the animals were bred for experimental purposes.


Housing and Feeding Conditions
- Full barrier in an air-conditioned room
- Temperature: 22 +/- 3°C
- Relative humidity: 55 +/- 10%
- Artificial light, sequence being 12 hours light, 12 hours dark
- Air change: 10 x / hour
- Free access to Altromin 1324 maintenance diet for rats and mice (lot no. 6636)
- Free access to tap water, sulphur acidified to a pH of approximately 2.8 (drinking water, municipal residue control, microbiological controls
at regular intervals)
- The animals were kept individually in IVC cages (except during the mating period when one female will be paired with one male), type III H,
polysulphone cages on Altromin saw fibre bedding (lot no. 011012)
- Certificates of food, water and bedding are filed at BSL BIOSERVICE
- Adequate acclimatisation period (at least 5 days) under laboratory conditions

Number and Sex of the Animals
80 animals (40 males and 40 females) were included in the study (10 male and 10 female animals per group).

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

Preparation of the Animals
Prior to the start of the treatment period a detailed clinical observation outside the home cage was made. Animals showing pathological signs
before the first administration were excluded from the study. Supplementary animals from the same delivery were provided in exchange.
Before the first administration all animals used for the study were weighed and assigned to the experimental groups with achieving a most
homogenous variation in body weight throughout the groups of males and females, respectively.

Experimental Groups and Doses
According to the results of the dose range finding study (BSL project no. 123917) and in consultation with the sponsor the following doses
were selected for the 3 dose groups (LD = low dose, MD = medium dose, HD = high dose) and 1 control group (C).
The animals were treated with the test item formulation or vehicle on 7 days per week for a period of 54 days, i.e. during 14 days of pre-mating
and maximum 14 days of mating in both males and females, during the gestation period and up to post-natal day 3 in females. Males were
dosed after the mating period until the minimum total dosing period of 28 days were completed.

Control: 0 mg/kg body weight
Low Dose: 100 mg/kg body weight
Medium Dose: 300 mg/kg body weight
High Dose: 1000 mg/kg body weight

The highest dose level was chosen with the aim of inducing toxic effects, but no death or severe suffering. Thereafter, a descending sequence
of dose levels was selected with a view to demonstrate any dosage related response and NOAEL. The doses were selected on the basis of data
from a Dose Range Finding Study (BSL study no. 123917).
The animals in the control group were handled in an identical manner to the test group subjects and received the vehicle using the same
volume as used for the high dose group.

 
Administration of Doses
The test item and vehicle were administered at a single dose to the animals by oral gavage. The application volume for all groups
was 5 mL/kg body weight. For each animal the individual dosing volume was calculated on the basis of the body weight most recently measured.

Details on mating procedure:

Mating was performed using a ratio of 1:1 (male to female). The vaginal smear of the females was checked every morning after the start of
the mating period to confirm the pregnancy. If the vaginal smear of a particular female was not found to be sperm-positive, the actual stage of
the estrus cycle on that day was documented. The day of the vaginal plug and/or sperm was considered as day 0 of gestation.
Females with unsuccessful mating will be allowed to mate with other male of the same group.
The cages were arranged in such a way that possible effects due to cage placement were minimised.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Each dosing concentration were analysed with respect to the target nominal concentration. Stability and homogeneity of the test item in
the vehicle were analysed for the low and high dose concentrations.
Samples for the nominal concentration verification were taken in study week 1 (first week of pre-mating period), 3 (first week of mating),
5 (gestation) and in the last week of the study (gestation/lactation) from all groups (16 samples).
Samples for homogeneity analysis were taken from the top, middle and bottom of the high dose and the low dose formulation in study
week 1 and 5 (12 samples).
Stability of Dosing Formulations was investigated by the sponsor. Hence, no formulation samples for stability analysis were stored during this study.
All formulation samples were stored at -20° C. These samples will be analysed after the completion of the toxicity study at BSL BIOSERVICE Scientific Laboratories GmbH under the BSL study no. 123899.

Duration of treatment / exposure:

The animals were treated with the test item formulation or vehicle. daily for a period of 54 days, i.e. during 14 days of pre-mating and
maximum 14 days of mating in both males and females, during the gestation period and up to post-natal day 3 in females.
Males were dosed after the mating period until the minimum total dosing period of 28 days were completed.

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:

Basis:
nominal conc.
0, 100, 300, 1000 mg/kg bw

No. of animals per sex per dose:

10 male and 10 female animals per group.

Control animals:

yes, concurrent vehicle

Details on study design:

Body Weight and Food Consumption
The body weight was recorded once before the assignment to the experimental groups, on the first day of administration and weekly during
the treatment period as well as at the end of the study. During pregnancy, females were weighed on gestation days (GD) 0, 7, 14 and 20 and
within 24 hours of parturition (day 0 post-partum) as well as day 4 post-partum along with pups. Any animals prematurely sacrificed were weighed
prior to the sacrifice.
Food consumption was measured weekly on the corresponding days of the body weight measurements after the beginning of the dose
administration. Food consumption was not measured during the mating period in males and females and the post-mating period in males.

Positive control:

None

Examinations

Parental animals: Observations and examinations:

Clinical Observations

General clinical observations were made at least once a day, preferably at the same time each day and considering the peak period of anticipated
effects after dosing. The health condition of the animals was recorded. Twice daily all animals were observed for morbidity and mortality except
on weekends and public holidays when observations were made once daily.
Females showing signs of abortion or premature delivery prior to the scheduled scarification of the animals were sacrificed and subjected to a
thorough macroscopic examination.
Clinical observations included spontaneous activity, lethargy, recumbent position, convulsions, tremors, apnoea, asphyxia, vocalisation, diarrhoea,
changes in the skin and fur, eyes and mucous membranes (salivation, discharge), piloerection and pupil size. Changes in gait, posture, response
to handling as well as the presence of clonic or tonic movements, stereotypes, difficult or prolonged parturition or bizarre behaviour were recorded.

Oestrous cyclicity (parental animals):

Not examined.

Sperm parameters (parental animals):

Not examined.

Litter observations:

Litter Observations

The duration of the gestation was recorded and was calculated from day 0 of the pregnancy. Each litter was examined as soon as possible
after delivery of the dam to establish the number and sex of pups, stillbirths, live births, runts and the presence of gross abnormalities.
Live pups were counted and sexed and litters weighed within 24 hours of parturition (day 0 post-partum) and on day 4 post-partum.
Live pups were identified by writing numbers on the back with the help of a permanent marker or by tattooing. In addition to the
observations of parent animals, any abnormal behaviour of the offspring was recorded.

Postmortem examinations (parental animals):

Pathology
All male animals were sacrificed after the completion of the mating period (total dosing period: 28 days) on study day 29 or 30, while female
animals were sacrificed on post-natal day 4 along with pups using an anaesthesia (ketamine/xylazin, 2:1, medistar Arzneimittel, lot no: 00312,
expiry date: 06/2014 and Serumwerk, lot no: 00512, expiry date: 07/2014) was used.
Dead pups and pups sacrificed on day 4 post-partum were carefully examined externally for gross abnormalities.
Non-pregnant females were sacrificed on study day 26 using the sperm-positive vaginal smear as an evidence of mating.
All animals were subjected to a detailed gross necropsy which includes careful examination of the external surface of the body, all orifices and
the cranial, thoracic and abdominal cavities and their contents.
Special attention was paid to the organs of the reproductive system. The ovaries, uterus with cervix, vagina, testes, epididymides, accessory sex
organs (prostate, seminal vesicles with coagulating glands as a whole), and all organs showing macroscopic lesions of all adult animals were
preserved in 10 % neutral buffered formalin, except for testes and epididymides which were preserved in modified Davidson’s Solution and
then transferred in 10 % neutral buffered formalin.
The number of implantation sites and corpora lutea was recorded for each parental female at necropsy. The number of corpora lutea and
implantation sites was recorded for any females sacrificed 24 to 26 days after the end of the pairing period with no evidence of mating
and for any females sacrificed on day 25 post-coitum due to non-delivery.


Organ Weights
The testes and epididymides of all male adult animals as well as the ovaries, uterus with cervix of all female adult animals were weighed.
Paired organs were weighed separately. Organ weights of animals found dead were not taken.
Additional organs of animals which died during the course of the study were preserved and examined histopathologically in order to determine
the cause of death.

 
Histopathology
A full histopathology was carried out on the preserved organs and tissues of all animals which died during the study or which were
euthanized due to morbidity.
Testes, epididymides, ovaries, uterus with cervix, vagina, accessory sex organs (prostate, seminal vesicle with coagulating gland) and all
organs showing gross lesions were examined in Control and HD animals and in non pregnant female animals of the LD and MD animals.
These examinations were extended to animals of all other dosage groups for treatment-related changes that are observed in the HD group.
Only organs and tissues of the other dosage groups showing changes in the high dose group were examined. Organs showing gross lesions
were examined in all groups.
For the testes, a detailed qualitative examination was made; taking into account the tubular stages of the spermatogenic cycle at evaluation of
additional hematoxylin-PAS (Periodic Acid Schiff) stained slides.
The histological processing of tissues to microscope slides was performed at the GLP-certified contract laboratory Propath UK Ltd, Willow Court,
Netherwood Road, Hereford HR2 6JU, Great Britain (test site for tissue processing). The histopathological evaluation was performed at the
GLP-certified contract laboratory KALEIDIS – Consultancy in Histopathology (test site for histopathology), 6 rue du Gers, 68300 Saint-Louis, France. Blocking, embedding, cutting, H&E staining and scientific slide evaluation was performed according to the corresponding SOP’s of the test sites.
The principal histopathological investigator provided the histopathology results to the study director by e-mail and sent a pathology phase
report to the study director upon the completion of the study.

Postmortem examinations (offspring):

Dead pups and pups sacrificed on day 4 post-partum were carefully examined externally for gross abnormalities.

Statistics:

The findings of this study were evaluated in terms of the observed effects, the necropsy and the microscopic findings.
The evaluation included the relationship between the dosing of the test item and the presence or absence, incidence and severity of abnormalities,
including gross lesions, identified target organs, infertility, clinical abnormalities, affected reproductive and litter performance, body weight changes, effects on mortality and any other toxic effects.
The gestation length, pre coital interval, the number of live births and post implantation loss, the number of pups with grossly visible abnormalities, the number of implantations, corpora lutea, litter size and litter weights were summarized in tabular form.
Parameters like body weight gain and food consumption were calculated for each animal as the difference in weight measured from one week to
the next. Mean body weights and food consumption were also presented as figures. The relative organ weights were calculated in relation to the
body weight (measured at necropsy) and are presented as percentage.
All results were reported in a tabular form (summarised in mean or summary tables and/or listed in individual data tables).
Analytical results and histopathological findings were presented in separate phase reports attached to this report.
A statistical assessment of the results of the body weight, food consumption, parameters of absolute and relative organ weights were performed
for each gender by comparing values of dosed with control animals of the main groups using a one-way ANOVA and a post-hoc Dunnett Test.
These statistics were performed with GraphPad Prism V.6.01 software (p<0.05 was considered as statistically significant).

Reproductive indices:

Viability Indices [%]

Offspring viability indices:

Viability Indices [%]

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

see details on results

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

see details on results

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

see details on results

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

see details on results

Other effects:

not examined

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

not examined

Details on results (P0)

Mortality
Two females (#71 and #76) treated at 1000 mg/kg/day were sacrificed moribund during the treatment period.
Macroscopic findings (e.g. gased parts of the GIT, diaerrhoea) may indicate a local effect of the test item. Furthermore, for animal No. 76
histopathological evaluation might indicate a local irritant effect of the test item formulation. In addition, abnormal breathing (present in both
animals) may indicate regurgitation of the test item followed by aspiration.
Hence, both moribund animals are not assumed to occur due to a systemic effect of the test item but due to aspiration and a direct effect in the lung.


Clinical Observations
In male animals, clear test item related clinical symptoms were found in HD group. The most prominent were: slight salivation
(0/10 C animals; 5/10 HD animals), diarrhoea (0/10 C animals; 10/10 HD animals), abnormal breathing (5/10 HD animals; 0/10 C animals)
and moving the bedding (0/10 C animals; 7/10 HD animals).
In female animals, test item related clinical symptoms were found, too. In particular, slight piloerection (1/10 C animals; 4/10 HD animals),
slight salivation (0/10 C animals; 7/10 HD animals), moderate salivation (0/10 C animals; 6/10 HD animals), moving the bedding
(0/10 C animals; 10/10 HD animals), diarrhoea (0/10 C animals: 6/10 HD animals) and abnormal breathing (0/10 C animals; 7/10 HD animals)
were observed.
.

Body Weight Development
In both males and females, the mean body weight increased with the progress of the study in the C, LD, MD and HD groups.
Throughout the treatment period, body weights were within the normal range of variation for this strain and no difference could be
found between treated and control groups.


Food Consumption
In male animals, a significant decreased food consumption (p<0.05) was recognized in HD group (136 g food within the first week) when compared to the C group (152.70 g within the first week).
In female animals, a significantly decreased food consumption (p<0.05) was measured for MD group (140.38 g between GD 14-20) when compared to C group (157.43 g between GD 14-20).
Since both influences on food consumptions had no direct impact on the body weight development, this is assumed to be test item related but is not associated with a toxicological relevance.


Precoital Interval and Duration of Gestation
No treatment-related effect was observed during the pre-coital interval or during the duration of gestation when compared with the control group. The values were comparable between the groups.

Pre- and Post-Natal Data
The group mean numbers of corpora lutea, number of implantation sites, number of live pups born on PND 0, percentage of pre-implantation
loss and post-implantation loss remained unaffected due to the treatment with test item when compared with the control group.
 
Reproductive Indices
A slightly reduced fertility index (number of pregnant females/ number of copulated females X 100) was observed in LD, MD, and
HD groups (90 %) when compared to C group (100 %). This is not assumed to be treatment related.
The viability index was slightly reduced in the C, MD, and HD groups. This was not assumed to be test item related.



Pathology
Few specific gross pathological changes were recorded for the male and female animals which were not considered to be treatment-related
because they occurred among C and treatment groups and only in individual cases.

Organ Weight
In males and females, there was no statistically significant difference in the absolute and relative organ weights of the treatment groups
when compared with the control group. Some tendencies to increased or decreased organ weights in treated groups (when compared to C group)
are not assumed to be test item related but incidental.

Histopathology
Two females treated at 1000 mg/kg/day were sacrificed moribund during the treatment period and showed gaseous distension of the
gastrointestinal tract. Their cause of death could not be determined by histopathological evaluation. Minimal mucosal hemorrhages and
mucosal single death of the gastric fundic mucosa seen microscopically in one of the decedents might indicate a local irritant effect of the
test item formulation. At terminal sacrifice, macroscopic organ findings were very few and not test item-related.
No test item-related histological findings were noted in the male and female reproductive organs. Female reproductive organs showed similar
post-partum histomorphology in the control and high dose group. The number of large ovarian corpora lutea was not essentially different
between control animals and animals treated at 1000 mg/kg/day. Each one female treated at 100, 300 and 1000 mg/kg/day were found not
to be pregnant at terminal sacrifice, but as a dose relationship was lacking this was not considered to be test item-related.

Effect levels (P0)

Key result

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Remarks on result:

other: Generation: P and F1 (migrated information)

Target system / organ toxicity (P0)

Key result

Critical effects observed:

no

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Description (incidence and severity):

see details on results

Mortality / viability:

no mortality observed

Description (incidence and severity):

see details on results

Body weight and weight changes:

no effects observed

Description (incidence and severity):

see details on results

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

see details on results

Histopathological findings:

not examined

Details on results (F1)

Litter Data
The sex ratio (m/f) of MD group was significantly (p<0.05) different when compared to C group. In particular, 1.9 (C) and 0.73 (MD)
were calculated. Although the sex ratio is slightly different at PND 4 (due to absent pups for dam Nos. 43 and 64), this sex ratio difference
is still statistically significant (C: 1.9; MD: 0.71; P<0.01).
This different sex ratio is not assumed to be related to the test item, since in HD no change could be found.
At PND 4, one pup of animal No. 43 (C), one pup of animal No. 64 (MD), as well as one pup of animal No. 78 (HD) was not present anymore.
This is assumed to be an incidental case and not test item related.


Litter Weight Data
Male and female litter weights were variable among the groups at PND 0 and PND 4. Furthermore, at PND 4 a significantly increased female
litter weight was observed in MD group (p<0.05; 70.62 g) when compared to C group (44.06 g).
These differences occurred due to the variable number of male and female pups and are not assumed to be test item related.
All other parameters of litter weight data like individual litter mean weight ant PND 0 and PND 4 were unchanged among the treated groups when
compared with the C group.

Pup Survival Data
A slightly reduced survival rate was observed for individual animals in C, MD, and HD group. This is assumed to be not treatment related,
but incidental.

Pup External Findings
No treatment-related gross external findings were observed in any of the treated groups. Few incidences of external findings were found among the groups which were considered to be spontaneous and not related to the test item.

Effect levels (F1)

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no adverse test item related effect observed

Target system / organ toxicity (F1)

Key result

Critical effects observed:

no

Overall reproductive toxicity

Reproductive effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

On the basis of this reproduction/ developmental toxicity screening test with the test item in male and female Wistar rats with dose levels
of 100, 300, and 1000 mg/kg body weight day the following conclusions can be made:
2 dead animals were recognized in HD group. Both mortalities are not considered to be a systemic toxic effect. Furthermore, clear test item
related clinical symptoms were found in HD group. These were clear signs of discomfort of the animals but do not display adverse toxic effects
per se.
Hence, the NOAEL of the substance is considered to be 1000 mg/kg for both – parental animals as well as reproductive/developmental toxicity.

Executive summary:

The aim of this study was to assess the possible effects of the test item on male and female fertility and embryofetal development after repeated dose

administration in Wistar rats.

The test item was administered daily in graduated doses to 3 groups of test animals, one dose level per group for a treatment period of 54 days, i.e. during 14 days

of pre-mating and maximum 14 days of mating in both males and females, during the gestation period and up to post-natal day 3 in females. Males were dosed

after the mating period until the minimum total dosing period of 28 days were completed. Animals of an additional control group were handled identically as the

dose groups but received aqua ad injectionem, the vehicle used in this study. The 4 groups comprised 10 male and 10 female Wistar rats.

During the period of administration, the animals were observed each day for signs of toxicity. Animals that died were examined macroscopically and at the

conclusion of the test, surviving animals were sacrificed and observed macroscopically.

Body weight and food consumption were measured weekly, except for food consumption measurements which were not taken during the mating period in female

animals and the mating and post-mating period in male animals.

After 14 days of treatment to both male and female, animals were mated (1:1) for a maximum of 14 days. The subsequent morning onwards the vaginal smears of

females were checked to confirm the evidence of mating. After the confirmation of the mating, females were separated and housed individually.

Each litter was examined as soon as possible after delivery of the dam to establish the number and sex of pups, stillbirths, live births, runts and the presence of

gross abnormalities. Live pups were counted, sexed and litters weighed within 24 hours of parturition and on day 4 post-partum.

The males were sacrificed after completion of the mating period on treatment days 29 and 30 and the females along with their pups were sacrificed on post natal day 4. Non-pregnant females were sacrificed on day 26.

The number of implantation sites and corpora lutea was recorded for each parental female at necropsy.

Pups sacrificed on postnatalday 4 and those found dead, were carefully examined for gross external abnormalities.

A full histopathological evaluation of the tissues was performed on high dose and control animals and in non pregnant female animals of the LD and MD animals.

These examinations were extended to animals of all other dosage groups for treatment-related changes that were observed in the high dose group. Only organs and tissues of the other dosage groups showing changes in the high dose group were examined.Any gross lesion macroscopically identified will be examined

microscopically in all animals.

The following doses were evaluated:

Control:                       0        mg/kg body weight

Low Dose:                   100     mg/kg body weight

Medium Dose:             300     mg/kg body weight

High Dose:                  1000   mg/kg body weight

The test item formulation was prepared freshly on each day of administration. The test item was dissolved in aqua ad injectionem and administered daily

during 14 days of pre-mating and 14 days of mating in both male and female animals, during the gestation period and up to post-natal day 3 in females.

Males were dosed for 28-30 days. Dose volumes were adjusted individually based on weekly body weight measurements. Theadministration volume

was 5 mL/kg body weight.

Summary Results

Two females (#71 and #76) treated at 1000 mg/kg/day were sacrificed moribund during the treatment period. Both deaths are not assumed to be

occurred due to a systemic toxic effect.

Several test item related clinical signs were found in male and female HD animals. These clinical symptoms display clearly discomfort of the animals

but not an adverse effect.

No change of body weight development was found for male and female treatment groups when compared to C group.

Food consumption was slightly changed in male HD group and female MD group. Both changes are not assumed to be of toxicological relevance.

The sex ratio (m/f) of MD group was significantly (p<0.05) different when compared to C group. This is not assumed to be related to the test item.

Male and female litter weights were variable among the groups at PND 0 and PND 4. Furthermore, at PND 4 a significantly increased female litter weight was

observed in MD group when compared to C group.

No treatment-related effect was observed during the pre-coital interval or during the duration of gestation when compared with the control group.

The values were comparable between the groups.

The group mean numbers of corpora lutea, number of implantation sites, number of live pups born on PND 0, percentage of pre-implantation loss and

post-implantation loss remained unaffected due to the treatment with test item when compared with the control group.

No test item related change was found regarding the reproductive indices in treatment groups when compared to C group.

A slightly reduced survival rate was observed for individual animals in C, MD, and HD group. This is assumed to be not treatment related, but incidental.

No treatment-related gross external findings were observed in any of the treated groups.

Few specific gross pathological changes were recorded for the male and female animals which were not considered to be treatment-related.

In males and females, there was no statistically significant difference in the absolute and relative organ weights of the treatment groups when compared with

the control group.

No test item-related histological findings were noted in the male and female reproductive organs.

Conclusion

On the basis of this reproduction/ developmental toxicity screening test with the substance in male and female Wistar rats with dose levels

of 100, 300, and 1000 mg/kg body weight day the following conclusions can be made:

2 dead animals were recognized in HD group. Both mortalities are not considered to be a systemic toxic effect. Furthermore, clear test item related clinical

symptoms were found in HD group. These were clear signs of discomfort of the animals but do not display adverse toxic effects per se.

Hence, the NOAEL of the substance is considered to be 1000 mg/kg for both – parental animals as well as reproductive/developmental toxicity.