3-iodo-2-propynyl butylcarbamate

Toxicity to reproduction

Administrative data

Endpoint:

two-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1986-02-06 to 1987-10-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPP 83-4 (Reproduction and Fertility Effects)

Version / remarks:

1982

Deviations:

no

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Version / remarks:

2001

Deviations:

no

Principles of method if other than guideline:

By the time the study was conducted the following parameters were not required and thus not determined:
- oestrus cycle
- sperm parameters

GLP compliance:

yes

Limit test:

no

Justification for study design:

SPECIFICATION OF STUDY DESIGN FOR TWO GENERATION REPRODUCTION TOXICITY STUDY:
The study was conducted in 1987 when the two generation reproduction toxicity study was an internationally recommended and accepted study type.

Test material

Test material information

Constituent 1

Reference substance name:

3-iodo-2-propynyl butylcarbamate

EC Number:

259-627-5

EC Name:

3-iodo-2-propynyl butylcarbamate

Cas Number:

55406-53-6

Molecular formula:

C8H12INO2

IUPAC Name:

3-iodoprop-2-yn-1-yl butylcarbamate

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Lot/batch No.of test material: P 2710-8511-R100

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Wiga GmbH
- Weight at study initiation: (P) Males: 175 - 235 g; Females: 140 - 185 g
- Housing: individually, except for mating and lactation
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: minimum 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature: 20 - 25 °C
- Humidity: 40 - 70 %
- Photoperiod: 12 / 12 hrs dark / hrs light

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Separate batches of diet were prepared at fixed concentrations for each treatment group. The weighed amount of test article was mixed with the final weight of the powdered diet in several steps (e.g. four steps for 30 kg formulated test article: 300 g, 5 kg, and 10 kg pre-mixture, 30 kg final mixture).

DIET PREPARATION
- Rate of preparation of diet: approx. monthly
- Mixing appropriate amounts with: powdered diet (Ssniff R 10)

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: up to 21 d
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
- After successful mating each pregnant female was caged: individually

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

As not initially requested, the diet was reformulated and test item amount was analysed for its stability over one month within the formulation.

Duration of treatment / exposure:

F0: 14 weeks pre-mating, throughout mating period and until day of necropsy (incl. pregnancy and lactation for females)
F1: from weaning until approx. 13 weeks of age, throughout mating until day of necropsy (incl. pregnancy and lactation for females)

Frequency of treatment:

daily via diet

Details on study schedule:

- Selection of parents from F1 generation when pups were approx. 21 days of age (after weaning).
- Age at mating of the mated animals in the study: not specified; approx. 14 weeks of age

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 ppm

Doses / concentrations 2

Dose / conc.:

120 ppm

Remarks:

equivalent to 8.4 to 10.7 mg/kg bw/d (males)
and 8.0 to 17.1 mg/kg bw/d (females)

Doses / concentrations 3

Dose / conc.:

300 ppm

Remarks:

equivalent to 20.7 to 26.1 mg/kg bw/d (males)
and 20.2 to 39.6 mg/kg bw/d (females)

Doses / concentrations 4

Dose / conc.:

750 ppm

Remarks:

equivalent to 50.5 to 62.8 mg/kg bw/d (males)
and 49.8 to 101.2 mg/kg bw/d (females)

No. of animals per sex per dose:

25 in P0 and P1, respectively

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: preliminary studies with male and female rats

- Rationale for animal assignment:
P animals:
The male and female animals were randomly allocated to treatment groups by a stratified randomization procedure based on body weight and were individually identified within the groups by earmarks. Each cage was identified by a group-related coloured card.

F1 animals:
Selection of weaned F1a pups to form F1 generation was made as follows: after all the F1a pups were weaned, one to three male and one to three female pups were selected from each litter - a minimum of 25 males and females per group - using a system of randomly drawn cards.
Selected F1 animals were identified by a combination of the litter number and Arabic numerals, if necessary. The animals were earmarked to ensure individual identification. Each cage was identified by a group-related coloured card.

Positive control:

not applicable

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly during pre-mating period; inseminated females were weighed on days 0, 6, 15, and 20 of gestation and lactating females on days 1, 4, 7, 14, and 21 of lactation

FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes; weekly during pre-mating period and following same intervals as body weight assessment during gestation and lactation period for females.
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE: No

Oestrous cyclicity (parental animals):

Estrous cyclicity was not evaluated.

Sperm parameters (parental animals):

Parameters examined in all male parental generations:
testis weight, epididymis weight

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 8 pups/litter (4/sex/litter as nearly as possible); excess pups were killed and discarded.

PARAMETERS EXAMINED
The following parameters were examined in F1 / F2 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was determined for pups born or found dead.

ASSESSMENT OF DEVELOPMENTAL NEUROTOXICITY: No

ASSESSMENT OF DEVELOPMENTAL IMMUNOTOXICITY: No

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals after delivery of litters sired.
- Maternal animals: All surviving animals after lactation period of 21 d

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera.

HISTOPATHOLOGY / ORGAN WEIGHTS
The tissues indicated below were prepared for microscopic examination:
target organs, testes, epididymides, prostate, and seminal vesicles in males and ovaries, uterus, cervix, and vagina in females
Organ weights were not determined.

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring not selected as parental animals and all F2 offspring were sacrificed after weaning.
- These animals were subjected to postmortem examinations: gross necropsy but not histopathology

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations including the cervical, thoracic, and abdominal viscera

Statistics:

For body weight, body weight gain, litter weight, and mean pup weight, the analysis of variance was performed with one factor TREATMENT. In case of suspected significance, the four groups were compared at each time by the Newman-Keuls test for multiple group comparisons (p < 0.05). The statistical evaluation was performed with the standard software package SAS (Statistical Analysis System).

Reproductive indices:

The mating performance (in days) was calculated for each group as:
Sum of days until successful insemination divided by the Number of inseminated animals

The fecundity index (in per cent) was calculated for each group as:
Number of pregnant animals divided by the Number of inseminated animals multiplied by 100

The insemination index (in per cent) was calculated for each group as:
Number of inseminated animals divided by the Number of paired animals multiplied by 100

The fertility index (in per cent) for male and female animals was calculated for each group as:
Number of males shown to be fertile divided by the Number of males mated multiplied by 100
And:
Number of pregnant females divided by the number of mated females multiplied by 100

The gestation index (in per cent) was calculated for each group as:
Number of females with live pups divided by Number of pregnant animals multiplied by 100

Offspring viability indices:

The live birth index (in per cent) was calculated for each litter as:
Number of pups alive day 1 divided by Total number of pups born multiplied by 100

The viability indices (in per cent) were calculated for each litter as:
Number of pups alive day 4/7/14/21 divided by the Number of pups alive day 1/4*/7/14 multiplied by 100

The weaning index (in per cent) was calculated for each litter as:
Number of pups alive day 21 divided by the Number of pups alive day 4* multiplied by 100

Percentage sex ratio was calculated as:
Number of males divided by the Number of pups multiplied by 100 and Number of females divided by the number of pups multiplied with 100

*) number of pups alive on day 4 post-partum after adjustment of litter size

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

no effects observed

Description (incidence and severity):

Males: No treatment-related clinical signs could be observed.

Females: No treatment-related clinical signs could be observed.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

There were no treatment-related mortalities of the parental animals (P0).
One female of the P0 generation (animal no. 186) of group 4 (750 ppm) died on day 9 post-partum. Necropsy showed findings in the spleen, kidneys, urinary bladder, and lungs.
The occurrence of one death is considered to be incidental.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Males: Body weight gain during the pre-mating period was slightly reduced in group 3 (300 ppm) and clearly reduced in group 4 (750 ppm) during the treatment period.

Females: Body weight gain of females during the pre-mating treatment, the gestation, and the lactation period was comparable in all groups.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Mean food consumption of group 4 (750 ppm) males was slightly reduced during the pre-mating treatment period. Mean food consumption of group 2 (120 ppm) and group 3 (300 ppm) males throughout the pre-mating treatment period was comparable with the control.

Mean food consumption of P0 females was generally similar in all groups throughout pre-mating treatment period, gestation, and lactation.

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

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

Two males in group 1 (Control) and one male in group 4 (750 ppm) had atrophy of the seminiferous tubules of the testes. The group 4 male also had an absence of sperm in one epididymis. A small focus of chronic inflammation was observed in the prostate of one group 1 male.

Lesions observed in the females were: an ovarian cyst in one group 1 female, dilated lumens of the uterus in three females of group 1 and four females of group 4, an implantation site in the uterus of one female of group 4, acute inflammation in the uterus of one female of group 4, chronic inflammation in the uterus of one female in group 1, one endometrial stromal polyp of the uterus in each of the groups 1 and 4, and minimal accumulations of acute inflammatory cells in the cervix of four females in group 1 and ten females in group 4.

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Description (incidence and severity):

There was no effect of treatment with test item on mating performance of fertility.

Duration of gestation:
All pregnant animals littered on day 21 or 22 of gestation. The mean duration of gestation was normal in all groups.

Number of pups: The live birth index was slightly reduced in group 4. Between days 1 and 4 p. p. pup losses were observed in all groups. After adjustment of litter size (day 4 p.p.) pup loss was similar in all groups.

The sex ratio was similar in all groups on days 1 and 21 of lactation.

Effect levels (P0)

1

Key result

Dose descriptor:

LOAEL

Effect level:

50.5 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

food consumption and compound intake

2

Key result

Dose descriptor:

NOAEL

Effect level:

20.7 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

food consumption and compound intake

3

Key result

Dose descriptor:

LOAEL

Effect level:

> 49.8 - < 101.2 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

4

Key result

Dose descriptor:

NOAEL

Effect level:

> 20.2 - < 39.6 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

Target system / organ toxicity (P0)

Key result

Critical effects observed:

no

Results: P1 (second parental generation)

General toxicity (P1)

Clinical signs:

no effects observed

Description (incidence and severity):

No treatment-related changes in appearance, behaviour, and general condition were observed.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One P1 male animal of group 4 (750 ppm) died on day 36 after start of mating; necropsy showed the right kidney developed as a tumour. This finding was considered to be incidental.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

Males:
Body weight gain of P1 males during the pre-mating treatment period was slightly lower in group 4 (750 ppm) than in the concurrent control group.
In group 2 (120 ppm) and group 3 (300 ppm) mean body weight gain during the pre-mating treatment period was comparable with the control group.

Females:
Mean body weight gain of females during the pre-mating treatment, the gestation, and the lactation period was comparable in all groups.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Mean food consumption was slightly reduced throughout most of the pre-mating treatment period in P1 males of group 4 (750 ppm).
In groups 2 and 3 of P1 males and in all dose groups of P1 females, mean food consumption was comparable with the control group.

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:

no effects observed

Description (incidence and severity):

Necropsy of P1 males and females revealed a few isolated findings in all groups (e.g. hydronephrosis and/or dilatation of the renal pelvis, or testis enlarged or reduced, or small cyst on the urinary bladder, or cyst on the right ovary or right uterine horn developed rudimentarily). These findings were considered to be not related to treatment.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

Atrophy of seminiferous tubules was observed in one male each in groups 1 (Control) and 4 (750 ppm). One male in group 4 had an absence of sperm in one epididymis.
Dilatation of the uterus was observed in three females in group 1 and nine females in group 4.

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Reproductive function / performance (P1)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Description (incidence and severity):

Mating performance and reproductive indices were comparable in all groups.

Duration of gestation:
The mean duration of gestation was normal in all groups.

Number of pups:
The live birth index was slightly lower in group 3 (300 ppm) and especially in group 4 (750 ppm).
Between days 1 and 4 p.p. pup losses were observed in all groups. After adjustment of litter size (day 4 p.p.) pup loss was similar in all groups.

The sex ratio was similar in all groups on days 1 and 21 of lactation.

Effect levels (P1)

1

Key result

Dose descriptor:

LOAEL

Effect level:

62.8 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

food consumption and compound intake

2

Key result

Dose descriptor:

NOAEL

Effect level:

26.1 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

body weight and weight gain

food consumption and compound intake

3

Key result

Dose descriptor:

LOAEL

Effect level:

> 52.7 - < 90.4 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

4

Key result

Dose descriptor:

NOAEL

Effect level:

> 20.3 - < 34 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

body weight and weight gain

Target system / organ toxicity (P1)

Key result

Critical effects observed:

no

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Description (incidence and severity):

There was no effect of treatment on post-natal growth. Mean pup weight in the treated groups was comparable with the control group.

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):

Macroscopic examination of pups died or sacrificed revealed no treatment-related changes.

Histopathological findings:

not examined

Other effects:

no effects observed

Description (incidence and severity):

Concerning all developmental landmarks examined (pinna unfolding, hair growth, incisor eruption, eye opening) its mean onset in the dose groups was comparable to the control group.
The employed functional tests (pupillary reflex, startle response) revealed no effect of treatment.
One pup of group 4 (750 ppm) showed externally an aplasia of the tail. The incidence of one malformation was considered to be incidental.

Developmental neurotoxicity (F1)

Behaviour (functional findings):

not examined

Developmental immunotoxicity (F1)

Developmental immunotoxicity:

not examined

Effect levels (F1)

1

Key result

Dose descriptor:

LOAEL

Generation:

F1

Effect level:

> 750 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

2

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

> 750 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Target system / organ toxicity (F1)

Key result

Critical effects observed:

no

Results: F2 generation

General toxicity (F2)

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Description (incidence and severity):

From day 1 to 14 p.p. mean pup weight was similar in all groups. On day 21 p.p. mean pup weight of group 3 (300 ppm) and group 4 (750 ppm) was slightly lower than in the control group. This finding was considered to be incidental.

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):

Macroscopic examination of F2 pups died or sacrificed revealed no treatment-related changes.

Histopathological findings:

not examined

Other effects:

no effects observed

Description (incidence and severity):

One F2 pup of group 2 (120 ppm) showed an exophthalmia and one of group 3 (300 ppm) showed a hydronephrosis at necropsy. The occurrence of these malformations was considered to be incidental.
The onset of all physical parameters examined (pinna unfolding, hair growth, incisor eruption, eye opening) was comparable in all groups.
The employed functional tests (pupillary reflex, startle response) revealed no effect of treatment. One male pup in group 2 (120 ppm) showed blindness on the right eye. This finding was considered to be incidental.

Developmental neurotoxicity (F2)

Behaviour (functional findings):

not examined

Developmental immunotoxicity (F2)

Developmental immunotoxicity:

not examined

Effect levels (F2)

1

Key result

Dose descriptor:

LOAEL

Generation:

F2

Effect level:

> 750 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

2

Key result

Dose descriptor:

NOAEL

Generation:

F2

Effect level:

> 750 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Target system / organ toxicity (F2)

Key result

Critical effects observed:

no

Overall reproductive toxicity

Key result

Reproductive effects observed:

no

Any other information on results incl. tables

Table 1       Multigeneration Reproduction Toxicity Study in Rats: Parental Effects

Parameter			Dose level [ppm]
			0		120		300		750		Dose-response +/-
		Genera­tion	m	f	m	f	m	f	m	f	m	f
Number of animals per group			25	25	25	25	25	25	25	25
Clinical Observations	Incidence
Injury on phalanx/tail/paw		F0	1	0	3	1	0	0	0	0	-	-
Injury in the eye			0	0	0	0	1	0	0	1	-	-
Swelling of ear			0	0	0	0	0	2	0	1	-	-
Loss of fur			0	0	0	0	0	0	0	0	-	-
Injury on phalanx/tail/paw		F1	0	1	1	1	1	1	0	0	-	-
Injury in the eye			0	0	0	0	0	0	0	0	-	-
Swelling of ear			0	0	0	0	1	0	0	0	-	-
Loss of fur			0	1	0	0	0	0	0	0	-	-
Mortality	Incidence	F0	0	0	0	0	0	0	0	1	-	-
Body weight gain	[g]
Week of treatment 1 to 14		F0	350.8	/	354.6	/	340.0	/	325.8	/	-	/
Week 1 to mating			/	121.4	/	121.6	/	131.0	/	124.2	/	-
Gestation day 0 to 20^1)			/	120.4	/	117.5	/	111.1	/	112.5	/	-
Lactation day 1 to 21^2)			/	14.8	/	17.0	/	19.0	/	26.6	/	-
Week of treatment 1 to 11		F1	350.6	/	373.8	/	355.6	/	331.8	/	-	/
Week 1 to mating			/	151.4	/	157.6	/	162.0	/	159.6	/	-
Gestation day 0 to 20^1)			/	115.4	/	113.6	/	108.9	/	114.5	/	-
Lactation day 1 to 21			/	21.0	/	23.4	/	31.5	/	37.4*	/	-
Food consumption (mean)	[g]
Week of treatment 1 to 14		F0	28.5	/	28.6	/	28.2	/	26.7*	/	-	/
Week 1 to mating			/	ne	/	ne	/	ne	/	ne	/	-
Gestation day 0 to 20^1)			/	ne	/	ne	/	ne	/	ne	/	-
Lactation day 1 to 21^2)			/	ne	/	ne	/	ne	/	ne	/	-
Week of treatment 1 to 14		F1	25.9	/	26.8	/	26.4	/	24.3*	/	-	/
Week 1 to mating			/	ne	/	ne	/	ne	/	ne	/	-
Gestation day 0 to 20^1)			/	ne	/	ne	/	ne	/	ne	/	-
Lactation day 1 to 21^2)			/	ne	/	ne	/	ne	/	ne	/	-

 

  Table 2 Multigeneration study in rats: Reproductive performance

Parameter			Dose level [ppm]
			0				120		300		750		Dose-response +/-
			historical control		concurrent control
		Genera­tion	m	f	m	f	m	f	m	f	m	f	m	f
Number of animals per group			25-30	25-30	25	25	25	25	25	25	25	25
Reproductive Performance
Number of inseminated animals		F0	/	--	/	25	/	25	/	23	/	24	/	-
		F1	/	--	/	25	/	25	/	25	/	25	/	-
Number of pregnant animals		F0	/	--	/	23	/	24	/	22	/	22	/	-
		F1	/	--	/	24	/	22	/	24	/	23	/	-
Number of animals with litters		F0	/	--	/	23	/	23	/	22	/	22	/	-
		F1	/	--	/	24	/	22	/	24	/	23	/	-
Insemination index	[%]	F0	93.3-100.0		100		100		92		96		-
		F1	76.0-100.0		100		100		100		100		-
Fecundity index	[%]	F0	73.9-96.7		92		96		95.7		91.7		-
		F1	68.4-100.0		96		88		96		92		-
Fertility index	[%]	F0	73.7-96.7		92		96		88		88		-
		F1	52.0-100.0		96		88		96		92		-
Gestation index	[%]	F0	95 0-100.0		100		95.8		100		100		-
		F1	96.0-100.0		100		100		95.8		95.7		-
Mean number of implantation sites		F0	12.3-15.5		13.6		14.5		14.0		13.3		-
		F1	12.0-15.7		14.2		14.0		13.7		14.3		-
Mean duration of gestation	[days]	F0	21-23		21.7		21.9		21.9		22.0		-
		F1	21-23		21.7		21.9		22.0		21.9		-

 

Table 3 Multigeneration reprotoxicity study: Litter development 

Parameter			Dose level [ppm]
			0				120		300		750		Dose-response +/-
			historical control		concurrent control
		Genera­tion	m	f	m	f	m	f	m	f	m	f	m	f
Number of animals per group					25	25	25	25	25	25	25	25
Live birth index		F1pups	50.0-100.0		95.3		96.9		95.2		87.8		-
		F2pups	11.1-100.0		94.5		97.0		89.1		80.3		-
Total litter losses		F1pups	--		3		0		1		3
		F2pups	--		9		3		4		4
Number of pups/litter found alive	Day 1	F1pups	1-20		12.3		12.5		11.9		10.9		-
		F2pups	0-19		12.7		12.7		11.2		9.9		-
	Day 4	F1pups	0-19		11.3		11.8		10.2		9.5		-
		F2pups	0-19		10.2		10.7		9.7		7.2		-
	Day 7^3)	F1pups	0-14		6.9		7.6		6.9		7.0		-
		F2pups	0-15		5.1		6.7		5.5		5.2		-
	Day 21	F1pups	0-14		6.4		7.0		6.4		6.2		-
		F2pups	0-11		3.6		5.6		3.8		4.2		-
Viability index (%)	day 1 to 4	F1pups	--		90.8		95.2		85.3		85.7		-
	day 4 to 7		--		91.5		95.1		92.5		94.6		-
	day 7 to 14		--		89.0		92.5		91.9		90.5		-
	day 14 to 21		--		100.0		98.5		100.0		97.4		-
	day 1 to 4	F2pups	--		77.8		84.8		88.6		70.7		-
	day 4 to 7		--		70.8		84.5		76.0		84.4		-
	day 7 to 14		--		53.1		79.7		66.2		76.4		-
	day 14 to 21		--		76.0		97.6		88.5		100.0		-
Mean Pup weight [g]	Day 1	F1pups	4.3-8.3		6.0		6.2		6.0		5.9		-
		F2pups	4.1-8.8		5.5		6.0*		5.9		5.7		-
	Day 4	F1pups	3.8-12.4		7.7		8.0		7.8		8.2		-
		F2pups	3.7-12.7		6.3		7.5*		7.0		7.2*		-
	Day 21	F1pups	9.9-60.0		39.5		40.5		38.4		37.8		-
		F2pups	15.3-55.6		37.3		40.7		33.9		32.6		-

 

¹⁾         day of pregnancy

²⁾         day post-partum

³⁾         adjustment of litter size at day 4

*          statistically significantly different from control, p<0.05

ne        no effect

 

Applicant's summary and conclusion

Conclusions:

In this two generation study, groups of 25 male and female rats of the Sprague Dawley strain in each of two generations were given test item admixed to the diet at concentrations of 0, 120, 300, and 750 ppm continuously from the start of treatment until necropsy. Slight toxicity in the P male animals such as reduced body weight gain and reduced food consumption during the pre-mating treatment period was observed at 300 and 750 ppm. Body weight gain and food consumption were also slightly reduced in F1 males of the high dose group (750 ppm) during the pre-mating treatment period. There was no evidence of toxicity in either of the two generations of animals given diet containing test item at a concentration of 120 ppm. Life birth index was slightly reduced in either generation at 750 ppm. The postnatal development of the offspring during the lactation period was, however, not affected. There were no effects on fertility or general reproductive performance over two successive generations in animals given test item in the diet at concentrations of 120, 300, and 750 ppm.

Executive summary:

Groups of 25 male and female rats of the Sprague Dawley strain in each of two generations were given test item admixed to the diet at concentrations of 120, 300, and 750 ppm continuously from the start of treatment until necropsy. A further group of 25 males and 25 females, given untreated diet, were applied as control.
After a 14 weeks pre-mating treatment period, the parental animals in each generation were mated and the females were allowed to rear their offspring to weaning.

Results can be summarized as follows:

1. There were no abnormalities of clinical condition in the parental animals in either generation considered to be associated with treatment. Necropsy revealed no treatment-related findings.

2. Treatment with the test item at 300 and 750 ppm was associated with reduced body weight gain in P male animals during the pre-mating treatment period.

At 750 ppm the body weight gain of the F1 male animals was also slightly reduced during the pre-mating treatment period.

3. At 750 ppm the mean food consumption of the P and F1 male animals was slightly reduced during the pre-mating treatment period.

4. There was no effect of treatment in either generation on mating performance or fertility. 

5. Live birth index was slightly reduced in either generation at 750 ppm. Post-natal viability was however not affected.Post-natal growth of the offspring of the treated P and F1 animals was comparable to the controls.

6. Physical and functional development of the offspring of the treated animals was similar to the controls in both generations.

In conclusion, administration of the test item by admixture to the basic powdered diet at concentrations of 300 and 750 ppm elicited slight toxicity in the P male animals (reduced body weight gain and reduced food consumption -group 4 only - during the pre-mating treatment period). Body weight gain and food consumption were also slightly reduced in F1 males of the high dose group (750 ppm) during the pre-mating treatment period.

There was no evidence of toxicity in either of the two generations of animals given diet containing test item at a concentration of 120 ppm.

Life birth index was slightly reduced in either generation at 750 ppm.The postnatal development of the offspring during the lactation period was however not affected. There were no effects on fertility or general reproductive performance over two successive generations in animals given test item in the diet at concentrations of 120, 300, and 750 ppm.