1,6-bis((dibenzylthiocarbamoyl)disulfanyl)hexane

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

no data

Link to relevant study records

Reference

Endpoint:

toxicity to reproduction

Remarks:

other: subacute toxicity study according to OECD 407

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: subacute toxicity study done according to OECD Guideline 407

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 407

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Winkelmann GmbH
- Age at study initiation: 5 to 6 weeks
- Fasting period before study:
- Housing:animals were housed individually in type II A-cages
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: at least 5 d


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 2°C
- Humidity (%): 55 +/- 5%
- Air changes (per hr): 15 to 20 changes per hour
- Photoperiod: 12hrs dark / 12hrs light)

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

the test substance was administered by gavage from the start of the study until day 27 for the recovery groups and until the day before scheduled sacrifice for the main group

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

during the study period, the test substance content in the vehicle was checked two times, determination of the test substance solved in corn oil was done by HPLC, homogeneity tested prior study and during study

Duration of treatment / exposure:

Test duration: 28 days

Frequency of treatment:

Daily

Details on study schedule:

28 d repeated dose study

Remarks:

Doses / Concentrations:
0, 40, 200, 1000 mg/kg bw
Basis:
nominal conc.

No. of animals per sex per dose:

Male: 5 animals at 0 mg/kg bw/day
Male: 5 animals at 40 mg/kg bw/day
Male: 5 animals at 200 mg/kg bw/day
Male: 5 animals at 1000 mg/kg bw/day
Female: 5 animals at 0 mg/kg bw/day
Female: 5 animals at 40 mg/kg bw/day
Female: 5 animals at 200 mg/kg bw/day
Female: 5 animals at 1000 mg/kg bw/day

Control animals:

yes, concurrent vehicle

Details on study design:

Main group: 0, 40, 200, 1000 mg/kg, 5 animals/dose/sex
Recovery group (14 d recovery period): 0, 1000 mg/kg 5 animals/dose group

Positive control:

none

Statistics:

Dunnett test, p value adjusted Welch test, Kruskal-Wallis test, Mann-Whitney.Wilcoxon test (U tests)

Clinical signs:

no effects observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Other effects:

no effects observed

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

not specified

histological examinations of sex organs (epididymides, ovaries, oviducts, prostate, testes, uterus with uterine cervix, vagina): no substance-related effects observed

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day

Sex:

male/female

Basis for effect level:

other: No effects in organ weights, gross pathology and histology in the sex organs evaluated

Reproductive effects observed:

not specified

Clinical observations: No mortality occurred during the study period.

There were no changes in clinical appearance, functional observations, body weights, and food consumption

The functional observations showed no signs or symptoms indicating evidence for systemic toxic and neurotoxic potential. Grip strength and motor activity measurements exhibited no treatment-related changes in both sexes at doses of 1000 mg/kg bw/d and below.

Laboratory findings: There were no biological significant effects of treatment on hematological and biochemical parameters. For a small number of parameters the differences between control and test groups attained a degree of statistical significance. However, the differences were small, not dose-related and inconsistent between the sexes.

Effects in organs: There were no treatment-related findings in organ weights, gross or microscopic pathology in rats of both sexes given 1000 mg/kg bw/d and below. Histopathological changes seen were of a minor nature and at a similar level to those seen in the controls.

No effects in organ weights, gross pathology and histology in the sex organs evaluated (epididymides, ovaries, oviducts, prostate, testes, uterus with uterine cervix, vagina)

Executive summary:

In a subacute toxicity study the test substance Vulcuren Trial Product KA 9188 was administered orally via gavage to male and female Wistar rats at target concentrations of 0, 40, 200 and 1000 mg/kg body weight for about 4 weeks. In parallel male and female rats (5 per sex and group) were treated with 0 and 1000 mg/kg body weight. These rats were observed for reversibility, continuance or delay occurrence of toxic effects during a recovery period of about 2 weeks. No differences regarding the survival rat or general behavior were noted compared to the untreated animals. In addition, no relevant differences were observed in mean feed intake and weight gain in any of the treatment groups evaluated compared to the negative control. No neuronal behavior effects were noted in any of the treatment groups. There were no toxicologically relevant changes in haematology and clinical chemistry in animals treated with the test compound. No biologically relevant effects on the organ weights were found in any of the rats treated with the test substance compared to the control animals.There was no evidence of any gross pathological and histopathological findings associated to dosing with the test compound up to the highest dose group (1000 mg/kg body weight) in both genders. In addition, no substance-related effects were noted in the evaluated sex organs. The author concluded that the administration of Vulcuren Trial Product KA 9188 to male and female Wistar rats for about 4 weeks was tolerated without adverse effects up to and including 1000 mg/kg. No delayed occurrence of toxic effects was observed during a recovery period of about 2 weeks (Bayer AG 2000d).

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

No adverse effects on the reproduction organs were seen up to the highest dose group evaluated in male and female rats (1000 mg/kg body weight).

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Non-human information

There is no reproductive toxicity screening test or generation study available. The subacute toxicity study with Vulcuren (purity: 99.7%) (Bayer AG 2000d) did not reveal any evidence of an adverse effect to the reproductive organs up to the highest dose tested (1000 mg/kg body weight and day).

As confirmed by literature (Mangelsdorf et al. 2003, Ulbrich & Palmer 1995, Janer et al. 2007 and Dent 2007, Sanbuissho 2009, Piersma et al 2011) histopathological examinations in repeated dose toxicity are of high value and high sensitivity for the evaluation of reproductive toxicity. Therefore at least for fertility assessment a repeated dose toxicity study showing no adverse effect should be taken into account. Also it is agreed that histopathological changes on the reproductive organs in repeated dose studies (subacute or longer exposure, see e.g. Ulbrich & Palmer 1995, Mangelsdorf et al. 2003) are indicative of effects on fertility. Therefore repeated dose toxicity studies should be considered as sufficient information for a DNEL calculation for fertility if histological examination of the reproductive organs is covered by repeated dose toxicity studies and the mode of action of the test substance does not give evidence for a specific toxicity (which is not the case with Vulcuren (purity: 99.7%).

For such an approach additional assessment factors are not needed as no or only small differences in NOAELs between e.g. two-generation studies and subchronic studies were observed in an retrospective analysis and two-generation study has had little impact on changing the overall NOAEL already available from a subchronic (or chronic) study. Therefore it is proposed by the group of researchers that in the absence of a two-generation study the NOAEL obtained from a subchronic study (or the lowest available studies) could be used as a reference point for deriving the DNEL (Janer at. al. 2007).

Therefore, for Vulcuren (purity: 99.7%) the NOAEL (1000 mg/kg body weight and day) from the subacute toxicity study (Bayer AG 2000) could be used for DNEL derivation.

Additional references: Mangelsdorf. et al., 2003: Some aspects relating to the evaluation of the effects of chemicals on male fertility. Regulatory toxicology and Pharmacology 36, 69-98; Ulbrich & Palmer, 1995: Detection of effects on male reproduction – a literature survey. J Am. College of Toxicology 14, 293-327; Janer et al., 2007: A retrospective analysis of the added value of the rat two-generation reproductive toxicity study versus the rat subchronic toxicity study. Reproductive Toxicology 24, 103-113; Dent, 2007: Strength and limitations of using repeated-dose toxicity studies to predict effects on fertility. Regulatory Toxicology and Pharmacology 48, 241-258; Sanbuissho et al., 2009: Collaborative work on evaluation of ovarian toxicity by repeated-dose and fertility studies in female rats. J Tox. Sci. 34: Special Issue SP1-SP22; Piersma et al., 2011: Combined retrospective analysis of 498 rat multi-generation reproductive toxicity studies: on the impact of parameters related to F1 mating and F2 offspring. Reproductive Toxicology 31, 392-401

Human information

There are no human data available.

Short description of key information:
Toxicity to reproduction
The data from the subacute toxicity study (Bayer 2000d) were used (as discussed above) for risk assessment. No adverse effects on the reproduction organs were seen up to the highest dose group evaluated in male and female rats (1000 mg/kg body weight). Therefore, for Vulcuren the DNELs derived for long-term exposure cover the aspect of fertility assessment.

Justification for selection of Effect on fertility via oral route:
See discussion

Justification for selection of Effect on fertility via inhalation route:
Data are available for the oral route. Since no local effects are reported in skin and eye irritation studies no local effects are assumed via dermal or inhalation route. Route-to-route extrapolation is possible for this compound.

Justification for selection of Effect on fertility via dermal route:
Data are available for the oral route. Since no local effects are reported in skin and eye irritation studies no local effects are assumed via dermal or inhalation route. Route-to-route extrapolation is possible for this compound.

Effects on developmental toxicity

Description of key information

A developmental toxicity study according to OECD TG 414 was conducted in rats. NOAEL maternal toxicity: 1000 mg/kg bw/day; NOEL appearance of placentas: 300 mg/kg bw/day An increased incidence of engorged placentas occurred at the 1000 mg/kg level in one litter, for which a treatment related effect cannot be excluded; NOAEL remaining developmental toxicity: 1000 mg/kg bw/day.
Human information
There are no human data available

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011/2012

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

Principles of method if other than guideline:

Twenty-five inseminated female Wistar rats each were treated daily orally by gavage with Vulcuren (purity 96.9 %) in corn oil from day 6 to day 20 p.c. in the following doses: 0, 100, 300, and 1000 mglkg body weight (bw)/day, respectively. The fetuses were delivered by cesarean section on day 21 of gestation. Investigation was performed on general tolerance of the test substance by the females as well as on its effect on intrauterine development.

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Wistar

Route of administration:

oral: gavage

Vehicle:

corn oil

Analytical verification of doses or concentrations:

yes

Details on mating procedure:

The animals were mated by placing two females overnight into a Type IIIh cage together with one male rat. If sperm was detected in the vaginal smear taken on the morning following mating, this day was regarded as day 0 of gestation.

Duration of treatment / exposure:

From days 6 to 20 p.c.

Frequency of treatment:

Daily

Duration of test:

Fetuses were delivered by cesarean section on day 21 of gestation. Investigation was performed on general tolerance of the test substance by the females as well as on its effect on intrauterine development.

Remarks:

Doses / Concentrations:
vehicle control
Basis:
other: control; corn oil

Remarks:

Doses / Concentrations:
100 mg/kg/day
Basis:
actual ingested

Remarks:

Doses / Concentrations:
300 mg/kg/day
Basis:
actual ingested

Remarks:

Doses / Concentrations:
1000 mg/kg/day
Basis:
actual ingested

No. of animals per sex per dose:

Twenty-five inseminated females per dose

Control animals:

yes, concurrent vehicle

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOEL

Effect level:

300 mg/kg bw/day (actual dose received)

Basis for effect level:

other: other:

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Dose descriptor:

NOAEL

Effect level:

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

Basis for effect level:

other: embryotoxicity

Abnormalities:

not specified

Developmental effects observed:

not specified

Analysis of Test Item in the Formulation:

Stability was confirmed analytically.

Appearance, Behavior, and Mortality:

No remarkable clinical observations occurred at dose levels up to 1000 mg/kg. Thus, appearance, behavior, and mortality were unaffected by treatment at dose levels up to 1000 mg/kg bw/day.

Body Weights:

Mean Body Weight Gain

Dose (mg/kg b.w./day):      

Dose (mg/kg b.w./day)

0 100 300 1000 mg/kg

absolute body weight gain (g) days 6 - 20 p.c.

103.6 109.3 103.0 99.0

absolute body weight gain (g) days 0 - 21 p.c.

142.2 149.5 142.7 139.6

corrected body weight gain (g) days 0 - 21 p.c.

50.4 51.5 50.8 44.7

Overall: absolute and corrected body weight gains were unaffected by treatment at dose levels up to 1000 mg/kg.

Food and Water Intake, Excretory Products:

Food intake, water intake, and fecal and urinary excretions were unaffected by treatment at dose levels up to 1000 mg/kg.

Necropsy:

One female of the 1000 mg/kg group showed a dilation of renal pelvis unilateral, for which a treatment related effect is not assumed, as two females of the current control group also revealed this finding, and because this finding is known as a spontaneous finding in the rat strain used. One female each of the 300 mg/kg and 100 mg/kg groups revealed a uterus filled with brownish or clear fluid, for which a treatment related effect is not assumed due to a lacking dose dependency.

Thus, no treatment related gross pathological findings occurred at dose levels up to 1000 mg/kg.

General Reproduction Data

Dose (mg/kg b.w./day)

0 100 300 1000

inseminated females

25 25 25 25

inseminated females evaluated

25 25 24 25

females with implantations

24 24 21 22

in % of those inseminated

96.0 96.0 87.5 88.0

corpora lutea

15.8 15.4 15.7 15.9

preimplantation loss

1.5 1.3 1.8 1.1

implantations

14.3 14.1 14.0 14.7

Overall: fertility rate (percentage of inseminated females with implantations), the mean numbers of corpora lutea, preimplantation losses, and implantation sites in the dose groups did not differ to a meaningful extent from the control group values indicating a homogeneous distribution regarding these parameters.

Gestation Rate:

Dose mg/kg b.w./day	Number of females with viable fetuses on day 21 p.c.	n % of females with implantations	number of total resorption
0	24	100.0	0
100	24	95.8	1
300	21	100.0	0
1000	22	100.0	0

The gestation rate was decreased at the 100 mg/kg group by one female with a total resorption, for which a treatment related effect is excluded due to a lacking dose dependency, and since single total resorptions are known as spontaneous findings in the rat strain used. Thus, the gestation rate was unaffected by treatment at dose levels up to 1000 mg/kg.

Mean Values of the Parameters of Intrauterine Development

Dose (mg/kg b.w./day)	0	100	300	1000
number of females
with implantations	24	24	21	22
with viable fetuses	24	23	21	22
mean values per female
placental weight in g	0.59	0.56	0.59	0.59
number of fetuses	13.3	14.5	13.4	13.8
postimplantation loss	0.9,	0.3	0.5	1.0
males in %	48.4	41.3	54.9	55.7
fetal weight in g	4.86	4.83	4.87	4.83

Overall: there are no effects on the above mentioned parameters of intrauterine development. The appearance of placentas revealed 10 engorged placentas out of 1 litter at the 1000 mg/kg, level, for which a treatment related effect cannot be excluded, because this value lay outside the range of historical control data. The mean placental weights were unaffected by treatment at dose levels up to 1000 mg/kg.

Fetal Malformations:

Dose (mg/kg b.w./day)	0	100	300	1000
cleft palate	-	-	-	1
eye ball(s) reduced in size with/without eyehole reduced in size	1	2 (2)	1	-
generalized edema	-	-	-	1
hairline ventricular septal defect of the heart	-	-	1	-
malformation of 1st sacral vertebral arch with/without cartilage, pelvis shift	3 (2)	2 (2)	1	1
7th cervical vertebral arch fused with 1st thoracic vertebral arch right, head of 1st rib missing right	-	-	1	-
multiple skeletal malformation of ribs, sternebrae, and vertebrae	-	1	-	-
humerus bent	-	-	-	!
clavicle bent	1	-	-	-
number of fetuses per group	320	333	282	303
number of fetuses with malformations	4	5	4	4
malformed fetuses per group (%)	1.3	1.5	1.4	1.3
number of litters per group	24	23	21	22
number of litters with malformations	3	5	4	4
malformed litters per group (%)	12.5	21.7	19.0	18.2

() number of litters affected

The overall incidences of fetuses or litters with malformations lay within the range of historical control data, revealed no statistical significance, and were thus unaffected by treatment at dose levels up to 1000 mg/kg.

The types of malformations observed in this study are generally a representative sample of spontaneous malformations in the rat strain used (microphthalmia, generalized edema, ventricular septal defect, vertebral malformations with pelvis shift, malformation of ribs and sternebrae, dysplastic forelimb bones and comparable with spontaneous findings in the current control group and/or historical control groups.

At the 1000 mg/kg level, one fetus revealed a cleft palate, which is a rare finding, but also known as a spontaneous finding in the rat strain used (for example 2 fetuses out of 1 litter in the unaffected low dose group of a prenatal developmental toxicity study, T7062991, conducted in 2002 in the same laboratory). Thus, a treatment related effect is not assumed for this isolated finding. Furthermore, each one fetus of the 1000 mg/kg group showed a generalized edema or a bent humerus, which are also known as spontaneous findings in the rat strain used. Therefore, a treatment related effect is not assumed for these findings.

All remaining findings revealed no dose dependency and were thus considered as incidental.

Thus, a treatment related effect on malformations (incidence or type) was not evident at dose levels up to 1000 mg/kg.

Fetal External and Visceral Deviations.

Dose (mg/kg b.w./day)	0	100	300	1000
slight edema	-	-	-	1
skin pale	-	-	-	1
brown mass in nuchal fatty tissue	1	-	1	-
duct of sublingual gland slightly enlarged	-	1	-	-
circumscribed hard whitish area in nasal cavities	2 (1)	4 (2)	-	3 (2)
retina slightly folded	-	2 (2)	-	-
slight dilation of 3rd brain ventricle	-	-	1	-
thyroid gland reduced in size	2 (2)	2 (1)	3 (3)	3 (2)
membranous part of trachea slightly folded, lying in tracheal lumen	-	-	1	-
thymus extended cranially	12 (10)	13 (11)	18 (14)	17 (10)
innominate artery reduce in length	1	-	-	1
innominate artery missing	-	1	-	-
pericard filled with dark brown mass	1	-	1	-
brown mass in abdominal cavity	7 (4)	12 (9)	14 (6)	7 (4)
brown spot(s) in the liver	8 (6)	15 (10)	15 (8)	10 (6)
dilation of stomach	-	1	-	-
slight dilation of renal pelvis	12 (6)	6 (5)	2* (2)	4 (4)
kidney flat and stretched	1	-	-	-
slight dilation of ureters	8 (4)	2 (2)	0*	2 (2)
testi(e)s lying on bladder	3 (3)	3 (2)	6 (6)	5 (5)
testi(e)s lying slightly more cranially	5 (3)	5 (5)	8 (8)	5 (5)
testi(e)s lying more cranially	-	1	1	1
right testis lying on the left side	-	2 (2)	-	-
number of fetuses per group	320	333	282	303
number of fetuses with deviations	39	54	50	41
fetuses with deviat. per group (%)	12.2	16.2	17.7	13.5
number of litters per group	24	23	21	22
number of litters with deviations	18	20	20	18
litters with deviat. per group (%)	75.0	87.0	95.2	81.8

() number of litters affected

Statistically significant difference to control * = p < 0.05

The overall incidences of fetuses or litters with external and visceral deviations were unaffected at dose levels up to 1000 mg/kg and revealed the highest value on a fetal basis in the 300 mg/kg group. The external and visceral deviations observed in this study were of a common type and comparable with spontaneous findings in the current control group and/or historical control groups (see Annex, Section 8.9.12) and represented the normal range of scattering in the rat strain used.

Histopathological evaluation of additional circumscribed hard whitish tissue in the nasopharynx was performed in another prenatal developmental toxicity study with the same rat strain and revealed calcium concrements without connection to the underlying tissue in the affected localizations. Calcium might have been dissolved from the fetal bones by the Wilson fixative and precipitated in the nasopharyngeal duct so that these findings were regarded as artifacts.

Thus, a treatment related effect on external and visceral deviations was not evident at dose levels up to 1000 mg/kg.

Fetal Skeletal Deviations Including Cartilaginous Deviations:

At the 1000 mg/kg level, fetal examinations for skeletal retardations and variations revealed statistically significantly retarded ossification of isolated localizations (1st distal phalanges of digits right, 5th proximal phalanges of toes bilateral), when calculation was done on a fetal basis, for which a treatment related effect was not evident, because statistical significance was lacking, when calculation was done on a litter basis, and since all values lay within the range of historical control data.

At the 300 mg/kg level, fetal examinations for skeletal retardations and variations revealed statistically significantly progressed ossification of a single localization (5th distal phalanges of toes left), when calculation was done on a fetal basis, for which a treatment related effect was not evident, because statistical significance was lacking, when calculation was done on a litter basis, and since a dose dependency was lacking.

At the 100 mg/kg level, fetal examinations for skeletal retardations and variations revealed statistically significantly retarded ossification of isolated localization (1st distal phalanges of digits right, calcaneus bilateral), when calculation was done on a fetal basis, for which a treatment related effect was not evident, because statistical significance was lacking, when calculation was done on a litter basis, and since a dose dependency was lacking. Furthermore statistically significantly progresses ossification occurred at this dose level at isolated localizations (1st distal phalanges of digits left, 2nd distal phalanges of digits right, 5th distal phalanges of digits bilateral, 1st distal phalanges of toes bilateral, 5th distal phalanges of toes right), when calculation was done on a fetal basis, for which a treatment related effect was not evident due to a lacking dose dependency, and because statistical significance was lacking, when calculation was done on a litter basis.

Evaluation of fetal cartilaginous tissue revealed no treatment related findings at dose levels up to 1000 mg/kg. Histopathological examination of several fetuses at all dose levels with additional alcian blue stained tissue between vertebral bodies of the spine most likely confirmed a staining artifact.

Thus, a treatment related effect on skeletal deviations (retardations, variations, including cartilaginous tissue findings) was not evident at dose levels up to 1000 mg/kg.

Executive summary:

In this OECD TG 414 guideline study twenty-five inseminated female Wistar rats each were treated daily orally by gavage with Vulcuren (purity 96.9 %) in corn oil from day 6 to day 20 p.c. in the following doses: 0, 100, 300, and 1000 mg/kg body weight (bw)/day, respectively. The fetuses were delivered by cesarean section on day 21 of gestation. Investigation was performed on general tolerance of the test substance by the females as well as on its effect on intrauterine development.

Toxicity to the Females:

Appearance, behavior, and mortality were unaffected by treatment at dose levels up to 1000 mg/kg bw/day. Absolute and corrected body weight gains were unaffected by treatment at dose levels up to 1000 mg/kg. Food intake, water intake, and fecal and urinary excretions were unaffected by treatment at dose levels up to 1000 mg/kg. No treatment related gross pathological findings occurred at dose levels up to 1000 mg/kg.

Toxicity to Intrauterine Development:

The gestation rate was unaffected by treatment at dose levels up to 1000 mg/kg. An increased incidence of engorged placentas occurred at the 1000 mg/kg level, for which a treatment related effect cannot be excluded, whereas weights of placentas were unaffected by treatment at dose levels up to 1000 mg/kg. Postimplantation loss and correspondingly the number of fetuses were unaffected by treatment at dose levels up to 1000 mg/kg. Fetal sex distribution was unaffected by treatment at dose levels up to 1000 mg/kg. The fetal weights were unaffected by treatment at dose levels up to 1000 mg/kg. A treatment related effect on malformations was not evident at dose levels up to 1000 mg/kg. A treatment related effect on external and visceral deviations was not evident at dose levels up to 1000 mg/kg. A treatment related effect on skeletal deviations (retardations, variations, including cartilaginous tissue findings) was not evident at dose levels up to 1000 mg/kg.

Overall:

NOAEL maternal toxicity: 1000 mg/kg bw/day

NOEL appearance of placentas: 300 mg/kg bw/day An increased incidence of engorged placentas occurred at the 1000 mg/kg level in one litter, for which a treatment related effect cannot be excluded.

NOAEL remaining developmental toxicity: 1000 mg/kg bw/day

Effect on developmental toxicity: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

300 mg/kg bw/day

Species:

rat

Quality of whole database:

A developmental toxicity study according to OECD TG 414 was conducted in rats. NOAEL maternal toxicity: 1000 mg/kg bw/day; NOEL appearance of placentas: 300 mg/kg bw/day An increased incidence of engorged placentas occurred at the 1000 mg/kg level in one litter, for which a treatment related effect cannot be excluded; NOAEL remaining developmental toxicity: 1000 mg/kg bw/day.

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

In a OECD TG 414 guideline study twenty-five inseminated female Wistar rats each were treated daily orally by gavage with Vulcuren (purity 96.9 %) in corn oil from day 6 to day 20 p.c. in the following doses: 0, 100, 300, and 1000 mg/kg body weight (bw)/day, respectively. The fetuses were delivered by cesarean section on day 21 of gestation. Investigation was performed on general tolerance of the test substance by the females as well as on its effect on intrauterine development.

Toxicity to the Females:

Appearance, behavior, and mortality were unaffected by treatment at dose levels up to 1000 mg/kg bw/day. Absolute and corrected body weight gains were unaffected by treatment at dose levels up to 1000 mg/kg. Food intake, water intake, and fecal and urinary excretions were unaffected by treatment at dose levels up to 1000 mg/kg. No treatment related gross pathological findings occurred at dose levels up to 1000 mg/kg.

Toxicity to Intrauterine Development:

The gestation rate was unaffected by treatment at dose levels up to 1000 mg/kg. An increased incidence of engorged placentas occurred at the 1000 mg/kg level, for which a treatment related effect cannot be excluded, whereas weights of placentas were unaffected by treatment at dose levels up to 1000 mg/kg. Postimplantation loss and correspondingly the number of fetuses were unaffected by treatment at dose levels up to 1000 mg/kg. Fetal sex distribution was unaffected by treatment at dose levels up to 1000 mg/kg. The fetal weights were unaffected by treatment at dose levels up to 1000 mg/kg. A treatment related effect on malformations was not evident at dose levels up to 1000 mg/kg. A treatment related effect on external and visceral deviations was not evident at dose levels up to 1000 mg/kg. A treatment related effect on skeletal deviations (retardations, variations, including cartilaginous tissue findings) was not evident at dose levels up to 1000 mg/kg.

Overall:

NOAEL maternal toxicity: 1000 mg/kg bw/day

NOEL appearance of placentas: 300 mg/kg bw/day An increased incidence of engorged placentas occurred at the 1000 mg/kg level in one litter, for which a treatment related effect cannot be excluded.

NOAEL remaining developmental toxicity: 1000 mg/kg bw/day

Justification for selection of Effect on developmental toxicity: via oral route:
A developmental toxicity study according to OECD TG 414 was conducted in rats.

Justification for selection of Effect on developmental toxicity: via inhalation route:
Data are available for the oral route. Since no local effects are reported in skin and eye irritation studies no local effects are assumed via dermal or inhalation route. Route-to-route extrapolation is possible for this compound.

Justification for selection of Effect on developmental toxicity: via dermal route:
Data are available for the oral route. Since no local effects are reported in skin and eye irritation studies no local effects are assumed via dermal or inhalation route. Route-to-route extrapolation is possible for this compound.

Toxicity to reproduction: other studies

Additional information

no data

Justification for classification or non-classification

Classification is not required based on the classification criteria 67/548/EWG and regulation no. 1272/2008 (GHS).