Registration Dossier

Toxicological information

Toxicity to reproduction

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Administrative data

Endpoint:
screening for reproductive / developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 2012-06-22 to 2012-11-05
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
Guideline study Study performed according to OECD test guideline No. 421 and in compliance with GLP.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)
Version / remarks:
1995
Deviations:
no
Principles of method if other than guideline:
not applicable
GLP compliance:
yes (incl. certificate)
Remarks:
Inspected from 2012-06-18 to 2012-06-20 / Signed on 202-09-19
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
impurity
Test material form:
liquid
Details on test material:
- Physical state: Colourless liquid
- Storage condition of test material: Room temperature, dry area, unopened containers, optimum temperature 11-25°C

Test animals

Species:
rat
Strain:
Crj: CD(SD)
Details on species / strain selection:
The rat (sexually mature, virgin) was chosen as the test species because of the requirement for a rodent species by regulatory agencies. The Crl:CD(SD) strain was used because of the historical control data available in this laboratory.
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River (UK) Ltd.
- Age at study initiation: approximately 77 days of age. Toxicity phase Females: 66-73 days of age.
- Weight at study initiation: (P) Males: 360-419 g; Main phase Females: 242-283 g; Toxicity phase Females: 214-256 g.
- Fasting period before study: none
- Housing: See Table 7.8.1/1
- Diet (e.g. ad libitum): SDS VRF1 Certified, powdered diet, ad libitum. Not contaminated.
- Water (e.g. ad libitum): potable water ad libitum. Not contaminated.
- Acclimation period: up to 12 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23
- Humidity (%): 40-70
- Air changes (per hr): at least 15
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 2012-08-12 To: 2012-10-12

Administration / exposure

Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on exposure:
DIET PREPARATION
- Rate of preparation of diet (frequency): every two weeks. A stability assessment of the test item confirmed that dietary formulations were stable for four days at ambient temperature and for 22 days when frozen (nominally -20 °C).
- Mixing appropriate amounts with (Type of food): SDS VRF1 Certified diet.
- Storage temperature of food: Any remaining formulated diet, that was not fed on the day of formulation, was stored frozen (nominally -20 °C) pending use on subsequent days.
Details on mating procedure:
- M/F ratio per cage: 1:1
- Length of cohabitation: up to 2 weeks
- Proof of pregnancy: ejected copulation plug / sperm in vaginal smear referred to as day 0 of pregnancy
- After successful mating each pregnant female was caged (how): individually in solid bottomed cages
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Shimadzu GC-2010 Plus gas chromatograph and flame ionisation detector. The analytical procedure was successfully validated for the test item in SDS VRF1 diet with respect to the linearity of detector response, specificity of chromatographic analysis, limit of detection, system precision, method accuracy and precision
The homogeneity was confirmed for the test item in SDS VRF1 diet formulations at nominal concentrations of 400 ppm and 12000 ppm. Stability was confirmed at ambient storage for up to 4 days and at frozen storage for up to 22 days.
The mean concentrations of test item in test formulations analysed for the study were within +10%/-15% of nominal concentrations, confirming accurate formulation.
Duration of treatment / exposure:
Males and toxicity phase female: minimum of 6 weeks.
Females: 2 weeks before paring, then throughout mating and gestation until Day 6 of lactation.
Frequency of treatment:
Continuous
Details on study schedule:
Following two weeks of treatment males and Main phase females were paired on a one-to-one basis from within the same treatment group for a period of up to two weeks.
Doses / concentrationsopen allclose all
Dose / conc.:
500 ppm (nominal)
Remarks:
31 mg/kg bw/day for males and 37-70 for females
Dose / conc.:
5 000 ppm (nominal)
Remarks:
309 mg/kg bw/day for males and 370-722 for females
Dose / conc.:
11 000 ppm (nominal)
Remarks:
698 mg/kg bw/day for males and 737-1467 mg/kg bw/day for females
No. of animals per sex per dose:
10/sex/dose + 5 females/control and top dose group
Control animals:
yes, plain diet
Details on study design:
- Dose selection rationale: The dietary concentrations employed in this study (0, 500, 5000 and 11000 ppm) were selected in conjunction with the Study Monitor based on the results from a previously conducted 28-day toxicity study with the test item. In that study, the high concentration of
10910 ppm and the intermediate concentration of 5455 ppm induced lower bodyweight gain, changes to clinical pathology, increased liver weight and hepatocellular hypertrophy. Males given 10910 ppm also had an increase in relative kidney weights. The liver changes were generally considered to be adaptive in nature whilst the kidney changes were consistent with well documented changes associated with the response of males to treatment with
hydrocarbons. The effects observed in the previously conducted 28-day toxicity study were considered not indicative of a hazard to human health and the No Observed Adverse Effect Level (NOAEL) was regarded as 545 ppm (representing an exposure level of 44 mg/kg bw/day for the males and 51 mg/kg bw/day for the females). For consistency and ease in comparing results between the 28-day toxicity study and this reproductive/developmental toxicity screening study, a similar high concentration of 11000 ppm was selected. This was predicted to generate an exposure level of approximately 1000 mg/kg bw/day which is the limit dose in most circumstances for OECD421 studies. The low and intermediate concentrations of 500 and 5000 ppm (representing an approximate exposure level of 30 and 300 mg/kg bw/day respectively for males and 45 and 450 mg/kg bw/day respectively for females) were selected to allow evaluation of a possible dose relationship for any treatment-related changes. The 500 ppm dose level was also selected as an anticipated No Observed Adverse Effect Level.
Positive control:
none

Examinations

Parental animals: Observations and examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: at least twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly for all animals. Main phase females: Days 0, 7, 14 and 20 after mating and Days 1 and 7 of lactation.

BODY WEIGHT: Yes
- Time schedule for examinations: Pre-Treatment (not reported). Day that treatment commences and weekly thereafter. Before necropsy. Main phase females: Days 0, 6, 13 and 20 after mating and Days 1, 4 and 7 of lactation.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): YES
Weekly.
The weight of food supplied to each cage, that remaining and an estimate of any spilled was recorded on a weekly basis throughout the study for the males and Toxicity phase females, and during the 2-week pre-pairing period for the Main phase females. From these records the mean weekly consumption per animal (g/animal/week) was calculated for each cage. Food
consumption was not recorded for males and Main phase females whilst paired for mating. For the Main phase females after mating, the weight of food supplied, that remaining and an estimate of any spilled was recorded daily between Days 0 to 19 after mating and Days 1 to 6 of lactation. From these records the mean daily consumption (g/animal/day) was calculated for each animal.

HAEMATOLOGY: YES
- Time schedule for collection of blood: Termination
- Anaesthetic used for blood collection: yes (Isoflurane)
- Animals fasted: No
- How many animals: All F0 animals (main study males and females and toxicity phase females)
- Parameters checked in Table 7.8.1/2 were examined.

CLINICAL CHEMISTRY: YES
- Time schedule for collection of blood: Termination
- Anaesthetic used for blood collection: yes (Isoflurane)
- Animals fasted: No
- How many animals: All F0 animals (main study males and females and toxicity phase females)
- Parameters checked in Table 7.8.1/2 were examined.

OTHER PARAMETERS INCLUDED
- Pre-coital interval
- Gestation length
Oestrous cyclicity (parental animals):
Dry smears For 15 days before pairing, using cotton swabs moistened with saline.
Wet smears after pairing until mating, using pipette lavage until evidence of mating was observed.
Sperm parameters (parental animals):
Parameters examined in male parental generation: testis weight, epididymis weight (caput, corpus and cauda).
Litter observations:
STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: no

PARAMETERS EXAMINED
The following parameters were examined in F1 offspring:
- Clinical observations: Observed approximately 24 hours after birth and then daily for evidence of ill-health or reaction to maternal treatment.
- Litter size: Daily on Days 1-7 of age.
- Sex ratio: Days 1, 4 and 7 of age.
- Individual offspring bodyweights: Days 1, 4 and 7 of age.

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities with an assessment of stomach for milk content. Possible cause of death was determined for pups born or found dead.
Postmortem examinations (parental animals):
SACRIFICE
- Male animals and toxicity phase females: in Week 7 after completion of the Week 6 investigations.
- Maternal animals: All surviving animals on Day 7 of lactation

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations

HISTOPATHOLOGY / ORGAN WEIGHTS
The tissues indicated in Table 7.8.1/3 were prepared for microscopic examination and weighed, respectively.
Light microscopy was performed on all premature death animals and at terminal sacrifice on Group 1 and 4 adult animals.
Postmortem examinations (offspring):
SACRIFICE
- The F1 offspring were sacrificed at 7 days of age (Intraperitoneal sodium pentobarbitone injection).
- These animals were subjected to postmortem examinations (macroscopic and/or microscopic examination) as follows: Examined externally, if found to be normal offspring discarded without further examination. Any externally abnormal offspring will also be examined internally. Abnormal tissues retained.
Sporadic deaths in early neonates: where possible fresh macroscopic examination (external and internal) with an assessment of stomach for milk content.
Statistics:
Data-types
The following data types were analysed at each timepoint separately:
- bodyweight, using absolute weights and gains over appropriate study periods.
- food consumption, over appropriate study periods.
- organ weights, both absolute and adjusted for terminal bodyweight.
- litter data

Methods
For categorical data, the proportion of animals will be analysed using Fisher’s Exact test for each treated group versus the control.
For continuous data, Bartlett’s test will first be applied to test the homogeneity of variance between the groups. Using tests dependent on the outcome of Bartlett’s test, treated groups will then be compared with the control group, incorporating adjustment for multiple comparisons where necessary.
Reproductive indices:
Percentage mating = Number animals mating x 100 / Animals paired.
Conception rate = Number animals achieving pregnancy x 100 / Animals mated.
Fertility index = Number animals achieving pregnancy x 100 / Animals paired.
Gestation index: Calculated for each group as: Number of live litters born x 100 / Number pregnant.
Offspring viability indices:
Post-implantation survival index = Total number offspring born x 100 / Total number uterine implantation sites.
Live birth index = Number live offspring on Day 1 after littering x 100 / Total number of offspring born.
Viability index = Number live offspring on Day 7 x 100 /Number live offspring on Day 1 after littering.
Sex ratio = Number of males in litter / Total number of offspring in litter x 100.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:
no effects observed
Description (incidence and severity):
There were no clinical signs observed at routine physical examination throughout the study that were considered to be related to treatment with the test substance.
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, non-treatment-related
Description (incidence and severity):
Mean bodyweight of males was considered unaffected by the presence of the test substance in the diet at levels at up to 11000 ppm. It was noted that mean weight gain was low during the third week of treatment among males receiving 5000 or 11000 ppm, with statistical significance attained in the 11000 ppm group; the aetiology of these isolated differences was uncertain but may reflect the impact of being paired with the females during that week.
The weight gain of Main phase females receiving 500, 5000 or 11000 ppm and of the Toxicity phase females receiving 11000 ppm was considered unaffected by the administration of the test substance throughout the study. Mean bodyweight gain of the Main phase females receiving 11000 ppm was lower than Control during Weeks 1 and 2 of treatment, with statistical significance attained for weight gain during Week 2 (55% of Control) and for overall weight gain from the start of treatment (60% of Control). Similar differences in weight gain were not apparent in the Toxicity phase females during the same period, and it was considered likely that the differences in weight gain in the Main phase females were fortuitous and unrelated to treatment with the test substance.
Mean food intake was generally similar in all groups of males and females throughout the study and was considered unaffected by the administration of the test substance at levels up to and including 11000 ppm.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
Mean achieved dosages (mg/kg bw/day) during the study are presented in Table 7.8.1/4. At the highest dietary concentration (11000 ppm) overall average intake was 698 mg/kg bw/day for the males, 737 mg/kg bw/day for the Toxicity phase females and between 804 and 893 mg/kg bw/day for the Main phase females up to the end of gestation. During lactation, intake was much higher than in other phases due to the increases in female food consumption in response to physiological demands. Achieved intakes in the lower treatment groups were in proportion to the levels present in the diet.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, non-treatment-related
Description (incidence and severity):
Assessment of haematological parameters at the end of the study revealed a slight decrease in reticulocyte counts for Main and Toxicity phase females receiving 11000 ppm (79-80% of Control) with statistical significance attained for the Toxicity phase females. Mean values were, however, within the Historical Control Data (HCD, 5-95% confidence limit) range of 0.097-0.253 x1012/L, and it was noted that the mean value for the Main phase Control females (0.307 x1012/L) was above the HCD range.
In addition, a statistically significant increase in neutrophil and monocyte counts (with concomitant increase in total white blood cell counts) was apparent in males receiving 11000 ppm; all values were within the HCD range (monocytes 0.14-0.68 x109/L; neutrophils 0.87- 4.14 x 109/L; total white blood cells counts 7.57-18.39 x 109/L). Similar leucocytic effects were not apparent in the Main or Toxicity phase females.
All other inter-group differences from controls were minor and lacked dose-relationship and were consequently attributed to normal biological variation.
Clinical biochemistry findings:
effects observed, non-treatment-related
Description (incidence and severity):
Biochemical changes in plasma at the end of the study were limited to increases in cholesterol concentrations in all groups of males and females receiving the test substance with statistical significance attained in the majority of groups, although there was no clear dose-response apparent and all values were within the HCD range (1.22-2.66 mmol/L for males and 1.43-3.08 mmol/L for females). All groups of treated males showed a statistically significant decrease in urea concentration although not dose related and within the HCD range (4.00-7.36 mmol/L). Conversely, Toxicity phase females receiving 11000 ppm showed
a slight, but statistically significant increase in urea concentrations, although values were within the HCD range (4.49-8.09 mmol/L). There was also a slight increase in total protein concentration for all groups of treated males, with 4/10, 3/10 and 7/10 males showing higher total protein concentration than the highest Control; all values were, however, within the HCD range (61-73 g/L). These differences in total protein concentration resulted in a statistically significant concomitant decrease in albumin/globulin ratio.
All other inter-group differences from controls were minor or lacked dose-relationship and were therefore attributed to normal biological variation
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
effects observed, non-treatment-related
Histopathological findings: non-neoplastic:
effects observed, non-treatment-related
Description (incidence and severity):
Linked to adaptive changes (liver) and male species-specific response to the administration with hydrocarbons (kidney changes).
Changes related to treatment with the test substance were seen in the liver of both sexes (including females from both the Main and Toxicity phases) and in the kidneys of male animals.
- Liver: Centrilobular hypertrophy was seen in both sexes given 5000 and 11000 ppm. A dose response was seen in the incidence in males and in the incidence and severity in females (including unmated females given 11000 ppm). See Table 7.8.1/5.
- Kidneys: In the cortex, an increase in the incidence and severity of hyaline droplets in tubules and basophilic tubules was seen in all groups of treated males. In the outer medulla, granular casts were also seen in all treated groups. A slight dose response was seen in terms of severity but generally all treated groups were similarly affected. See Table 7.8.1/6.
Histopathological findings: neoplastic:
no effects observed
Other effects:
no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:
no effects observed
Description (incidence and severity):
Oestrous cycles were unaffected by treatment, with the majority of females in all treated groups showing regular cycles, as in the Control group.
Reproductive function: sperm measures:
not examined
Reproductive performance:
no effects observed
Description (incidence and severity):
Mating performance was considered unaffected by treatment with the test substance, with all pairs mating and 9 out of 10 pairs in each treated group mating within four days (ie. at the first oestrus opportunity).
There was no evidence of dystocia, and with the exception of one non-pregnant female in the 500 ppm group, all females successfully gave birth to live young. There was no effect of treatment with the test substance on gestation length, with all gestation lengths within the expected range of 22 to 23 days. The gestation index within all treated groups was 100%.

Effect levels (P0)

open allclose all
Key result
Dose descriptor:
NOAEL
Effect level:
698 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male
Basis for effect level:
other: No effect indicative of a hazard to human health was identified
Key result
Dose descriptor:
NOAEL
Remarks:
Main phase females
Effect level:
>= 804 - <= 1 467 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
female
Basis for effect level:
other: No effect indicative of a hazard to human health was identified
Key result
Dose descriptor:
NOAEL
Remarks:
Toxicity phase females
Effect level:
737 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
female
Basis for effect level:
other: No effect indicative of a hazard to human health was identified

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):
There were no clinical signs observed among the F1 offspring which were attributable to parental treatment with the test substance.
Dermal irritation (if dermal study):
not examined
Mortality / viability:
no mortality observed
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Offspring absolute body weight on Day 1 of age and body weight gain up to Day 7 of age was similar in all groups and no effect of treatment with the test substance was inferred.
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:
no effects observed
Description (incidence and severity):
There were no macroscopic findings observed in the low number of offspring that died prior to scheduled termination or among those offspring killed on Day 7 of age that were attributable to parental treatment with the test substance.
Histopathological findings:
not examined
Other effects:
no effects observed
Description (incidence and severity):
There was considered to be no effect of parental treatment with the test substance at any dietary inclusion level investigated on mean litter size, sex ratio or offspring survival to Day 7 of age.
It was noted that at 11000 ppm post implantation survival index, and consequently litter size, was slightly low. This was attributable to one litter with atypically low post implantation survival and litter size, while these parameters were similar to Controls in the remaining nine litters in this group.

Developmental neurotoxicity (F1)

Behaviour (functional findings):
not examined

Developmental immunotoxicity (F1)

Developmental immunotoxicity:
not examined

Effect levels (F1)

Key result
Dose descriptor:
NOAEL
Remarks:
Pups up to lactation day 7
Generation:
F1
Effect level:
11 000 ppm (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No effect indicative of a hazard to human health was identified
Remarks on result:
other: (698 mg/kg bw/day for the males, 804-1467 mg/kg bw/day for the main reprotoxicity phase females and 737 mg/kg bw/day for the toxicity phase females)

Target system / organ toxicity (F1)

Key result
Critical effects observed:
no

Overall reproductive toxicity

Key result
Reproductive effects observed:
no

Any other information on results incl. tables

Table 7.8.1/4: Achieved dosages (mg/kg bw/day)

 

Males

Females

Dietary Conc. (ppm)

500

5000

11000

500

5000

11000

Period

 

Weeks 1-6 (males and Toxicity phase females)

31

309

698

-

-

737

Main phase females before pairing

-

-

-

37

370

804

Main phase females during gestation

-

-

-

37

393

893

Main phase females during Days 1-6 of lactation

-

-

-

70

722

1467

Table 7.8.1/5: Summary of treatment related findings in the liver for animals killed after at least 4 weeks of treatment

Summary of treatment related findings in the liver for animals killed after at least 4 weeks of treatment

Group/sex

1M

2M

3M

4M

1F

2F

3F

4F

Dose (ppm)

0

500

5000

11000

0

500

5000

11000

 

Hepatocyte hypertrophy, centrilobular

 

 

 

 

 

 

 

 

Minimal

1

0

3

6

0

0

6

6

Slight

0

0

1

1

0

0

0

7

Total

1

0

4

7

0

0

6

13

 

Number of tissues examined

10

10

10

10

15

10

10

15

Table 7.8.1/6: Summary of treatment related findings in the kidneys for males killed after 4 weeks of treatment

Summary of treatment related findings in the kidney for males killed after 4 weeks of treatment

Group/sex

1M

2M

3M

4M

Dose (ppm)

0

500

5000

11000

 

Cortex – Tubules with hyaline droplets

 

 

 

 

Minimal

3

0

0

0

Moderate

0

10

7

7

Marked

0

0

3

3

Total

3

10

10

10

 

Cortex – Basophilic tubules

 

 

 

 

Minimal

1

6

6

3

Slight

0

1

1

1

Moderate

0

2

3

5

Total

1

9

10

9

 

Outer Medulla – Granular casts

 

 

 

 

Minimal

0

6

5

3

Slight

0

0

1

2

Total

0

6

6

5

 

Number of tissues examined

10

10

10

10

Applicant's summary and conclusion

Conclusions:
Dietary administration of the test substance to CD rats for approximately 7 weeks at concentrations up to and including 11000 ppm was well tolerated, and there was no evidence of any adverse effects on reproductive capacity or performance of the adult rat or on the survival or development of the F1 offspring up to Lactation Day 7. The No Observed Adverse Effect Level (NOAEL) was considered to be 11000 ppm (698 mg/kg bw/day for the males, 804-1467 mg/kg bw/day for the Main phase females, 737 mg/kg bw/day for the Toxicity phase females).
Executive summary:

A reproduction/developmental toxicity screening test was conducted with the test substance according to the OECD test guideline No. 421 and in compliance with GLP. The objective of this study was to assess the general systemic toxic potential of the test item following continuous dietary administration to Crl:CD(SD) rats over a period of at least six weeks, including a screen for reproductive/developmental effects after two weeks of treatment. Three groups, each comprising ten males and ten Main phase females received the test substance orally via the diet at concentrations of 500, 5000 or 11000 ppm; these concentrations provided equivalent doses of 31, 309 and 698 mg/kg bw/day for males and 37-70, 370-722 and 737-1467 mg/kg bw/day for females. A similarly constituted Control group received untreated diet over the same treatment period. The Control and 11000ppm groups also included five Toxicity phase females which were not mated and were maintained for the purposes of assessing systemic toxicity in the non-pregnant female. The males and Toxicity phase females were treated for at least six weeks. The Main phase females were treated for two weeks before pairing, throughout pairing, gestation and lactation until termination on Day 7 of lactation.

During the study, data was recorded on clinical condition, bodyweight, food consumption, achieved dosage, haematology, blood chemistry, oestrous cycles, pre-coital interval, mating performance and fertility and gestation length. Organ weight, macroscopic and microscopic investigations were undertaken for all adult animals. The clinical condition of offspring, litter size and survival, sex ratio and bodyweight were assessed and macroscopic pathology investigations were undertaken.

 

Dietary administration of the test substance at concentrations up to and including 11000 ppm was well tolerated and there were no mortalities. Clinical condition was unaffected by treatment, and there were no effects on bodyweight performance or food intake at any dietary level investigated.

Oestrous cycle length, mating performance, fertility, reproductive capacity and gestation length were unaffected by treatment with the test substance and with the exception of one Main phase female receiving 500 ppm, all Main phase females were pregnant, successfully gave birth and reared the F1 offspring to scheduled termination on Day 7 of age. Bodyweight gain, survival and development of the offspring to Day 7 of age was unaffected by parental treatment. At scheduled termination of the adult animals, there were no treatment related macroscopic or microscopic abnormalities detected in the reproductive organs.

Mean adjusted liver weight was statistically significantly high among males receiving 11000 ppm and females receiving 5000 or 11000 ppm. These differences correlated with an increased incidence and/or severity of hepatocyte hypertrophy.

In all groups of treated males kidney weight was increased. These differences from Control were attributable to an increased incidence and severity of hyaline droplets in the tubules of the cortex and granular casts in the outer medulla, and may relate to the observed decreases in plasma urea concentrations in all groups of treated males and with the higher neutrophil and monocyte counts recorded among males receiving 11000 ppm.

Some minor non-adverse haematological and biochemical changes were evident at scheduled termination after approximately 7 weeks of treatment. A slight decrease in reticulocytes was evident in females receiving 11000 ppm, plasma cholesterol levels were high among all groups of treated males and females, and total protein concentrations were slightly increased in all groups of treated males.

Dietary administration of test substance to CD rats for approximately 7 weeks at concentrations up to 11000 ppm was well tolerated, and there was no evidence of any adverse effects on reproductive capacity or performance of the adult rat or on the survival or development of the F1 offspring up to Lactation Day 7.

The liver changes (hepatocyte hypertrophy) observed in males at 11000 ppm and in females at 5000 and 11000 ppm are considered to be adaptive in nature and non-adverse. The kidney changes detected in all groups of treated males (hyaline droplets in tubules and granular casts) were consistent with well-documented species-specific responses of the male rat in response to the administration with hydrocarbons. This effect is, therefore, not indicative of a hazard to human health and, for purposes of hazard evaluation, within the context of this reproductive/developmental toxicity screening study the No Observed Adverse Effect Level (NOAEL) was considered to be 11000 ppm (i.e. 698 mg/kg bw/day for the males, 804-1467 mg/kg bw/day for the main reprotoxicity phase females and 737 mg/kg bw/day for the toxicity phase females).

 

This study is considered as acceptable and satisfies the requirement for the toxicity to the reproduction endpoint.