Allyl isothiocyanate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

In a two-generation study with rats, the NOAEL for effects in P0 generation could not be established due to adverse effects observed also at the lowest dose (20 mg/kg bw/day). No effects on reproductive toxicity were observed in P0 and in P1. Neither in F1 was possible to establish a NOAEL, due to the adverse effects observed also at the lowest dose (20 mg/kg bw/day). In F2 generation, the NOAEL was established at 20 mg/kg bw/day.

Link to relevant study records

Reference

Endpoint:

two-generation reproductive toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3800 (Reproduction and Fertility Effects)

GLP compliance:

yes

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on mating procedure:

Rats were administered the test substance for at least 70 consecutive days prior to mating.
The F0 and F1 males continued to receive the test substance throughout mating and through the day prior to euthanasia.
The F0 and F1 females continued to receive the test substance throughout mating, gestation, and lactation, and through the day prior to euthanasia.

Duration of treatment / exposure:

F0 males and females were dosed for 127–132 consecutive days, and F1 males and females were dosed for 139–148 consecutive days.

Frequency of treatment:

Daily

Dose / conc.:

20 mg/kg bw/day (nominal)

Dose / conc.:

40 mg/kg bw/day (nominal)

Dose / conc.:

60 mg/kg bw/day (nominal)

No. of animals per sex per dose:

Three groups of male and female Crl:CD(SD) rats (25/sex/group)
25 rats/sex/group received the vehicle (corn oil) on a comparable regimen.

Control animals:

yes, concurrent vehicle

Oestrous cyclicity (parental animals):

Vaginal lavages were performed daily for determination of estrous cycles beginning 21 days prior to cohabitation.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

No test substance-related clinical observations were noted for F0 and F1 males and females in the 20 mg/kg/day group.
Test substance-related, increased incidences of red material around the nose and/or mouth were noted for F0 and F1 males and females in the 40 and 60 mg/kg/day groups and increased incidences of mucoid feces and yellow and/or brown material around the urogenital and/or anogenital areas were noted for all F0 males and females in the 60 mg/kg/day group generally throughout the treatment period; these observations were noted primarily at the time of dose administration and/or 3-4 hours following dose administration.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Lower mean body weight gains were noted in the 40 mg/kg/day group F0 males during the pre-mating period (Study Days 0–69) and in the 60 mg/kg/day group F0 males throughout the entire generation (Study Days 0–127) compared to the control group. In addition, mean body weights in the 40 and 60 mg/kg/day group F0 males were up to 6.7% and 16.3% lower, respectively, than the control group during these intervals.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Test substance-related lower mean food consumption was noted in the 40 and 60 mg/kg/day group F0 males during the first week of dosing (Study Days 0–7). For the remainder of the study, mean food consumption for F0 males in all test substance-treated groups was similar to or higher than the control group; the higher food consumption values were likely due to the high caloric content and volume of the vehicle (corn oil).

Food efficiency:

effects observed, non-treatment-related

Description (incidence and severity):

Mean food efficiency in the 40 and 60 mg/kg/day group F0 males was generally lower than the control group throughout the study. Mean F0 male mean body weights, body weight gains, and food efficiency at 20 mg/kg/day were similar to the control group. In addition, F0 female mean body weights, body weight gains, food consumption, and food efficiency during the pre-mating period, gestation, and lactation were unaffected by test substance administration.

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

There were no test substance-related effects on F0 and F1 male and female mating and fertility, male copulation, and female conception indices, estrous cycle length, pre-coital interval, or spermatogenesis parameters (motility, progressive motility, testicular and epididymal sperm numbers, sperm production rate, and sperm morphology) at any dosage level.
No test substance-related effects on parturition were noted for F0 females at 20, 40, and 60 mg/kg/day.

Dose descriptor:

NOAEL

Remarks:

parental toxicity

Sex:

male/female

Remarks on result:

not determinable

Dose descriptor:

NOAEL

Remarks:

reproductive toxicity

Effect level:

60 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reproductive performance

Critical effects observed:

yes

Lowest effective dose / conc.:

20 mg/kg bw/day (nominal)

Organ:

bladder

stomach

other: eye

Treatment related:

not specified

Relevant for humans:

not specified

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Test substance-related, lower mean body weights and body weight gains were noted in the 40 and 60 mg/kg/day group F1 males throughout the entire generation (PND 21–161). In the 40 and 60 mg/kg/day group F1 females, lower mean body weight gains were noted during the first 2 weeks of the pre-mating period (PND 21–28 and PND 21–35 at 40 and 60 mg/kg/day, respectively) and resulted in lower mean body weights during PND 21–35 at 40 mg/kg/day and PND 21-63 at 60 mg/kg/day; mean body weights and body weight gains in these groups were similar for the remainder of the pre-mating period.
Mean maternal body weights, body weight gains, food consumption, and food efficiency for F1 females at all dosage levels were generally similar to the control group during gestation. In the 60 mg/kg/day group F1 females, mean body weights that were up to 8.1% lower than the control group were noted during Lactation Days 1–21 and were considered test substance-related and adverse; mean body weight gains in this group were similar to the control group.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Mean food consumption (g/animal/day values) for the 60 mg/kg/day group F1 males was lower than the control group during the pre-mating period (PND 28–98).
Test substance-related, lower mean food consumption was noted in the 60 mg/kg/day group F1 females when the entire lactation period (Lactation Days 1–21) was evaluated compared to the control group; mean food efficiency in this group was generally similar to the control group. Mean body weights, body weight gains, food consumption, and food efficiency in the 20 and 40 mg/kg/day group F1 females was generally similar to the control group during lactation.

Ophthalmological findings:

effects observed, treatment-related

Description (incidence and severity):

A test substance-related increased incidence of bilateral cataracts were noted in the 40 and 60 mg/kg/day group F1 males and females during the ophthalmic examination and were considered test substance-related. These findings correlated with adverse ocular clinical and histopathological findings noted for F1 males and females at these dosage levels.

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Test substance-related findings noted for F1 animals consisted of lower brain weights in the 40 and 60 mg/kg/day group males and females, higher adrenal gland weights in the 40 and 60 mg/kg/day group females, higher liver weights in the 40 and 60 mg/kg/day group males and 20, 40, and 60 mg/kg/day group females, small eyes, enophthalmus, retinal dysplasia, and/or cataract formation in the 20, 40, and 60 mg/kg/day group males and 40 and 60 mg/kg/day group females, small optic nerve in the 60 mg/kg/day group males, mucosal hyperplasia of the urinary bladder in the 20, 40, and 60 mg/kg/day group males and females, and squamous hyperplasia of the non-glandular stomach in the 20, 40, and 60 mg/kg/day group males and females.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

The adverse findings included the gross and microscopic changes in the eye, small optic nerve, squamous hyperplasia of the stomach, and mucosal hyperplasia of the urinary bladder.

There were no test substance-related effects on F0 and F1 male and female mating and fertility, male copulation, and female conception indices, estrous cycle length, pre-coital interval, or spermatogenesis parameters (motility, progressive motility, testicular and epididymal sperm numbers, sperm production rate, and sperm morphology) at any dosage level.
In the 60 mg/kg/day group, difficult parturition resulted in the moribundity of 2 F1 females (as noted previously). No other signs of dystocia were noted in F1 females at any dosage level.

Dose descriptor:

NOAEL

Based on:

test mat.

Sex:

male/female

Basis for effect level:

ophthalmological examination

histopathology: neoplastic

Remarks on result:

other: not determinable due to adverse effects observed also at the lowest dose (20 mg/kg bw/day)

Dose descriptor:

NOAEL

Effect level:

60 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reproductive performance

Critical effects observed:

yes

Lowest effective dose / conc.:

20 mg/kg bw/day (nominal)

Organ:

bladder

stomach

other: eye

Treatment related:

yes

Relevant for humans:

not specified

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

In the 60 mg/kg/day group F1 pups, a test substance-related clinical observation of small stature was noted; no test substance-related clinical observations were noted in F1 pups at 20 and 40 mg/kg/day or F2 pups at any dosage level.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Lower male and female mean offspring body weight gains were noted prior to culling (PND 1-4) in F1 and F2 pups at 40 and 60 mg/kg/day and following culling (PND 4–21) in F1 pups at 40 and 60 mg/kg/day and F2 pups at 60 mg/kg/day compared to the control group and resulted in lower mean body weights in these groups generally throughout the postnatal period.

Sexual maturation:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related effects on balanopreputial separation or vaginal patency in the 20, 40, and 60 mg/kg/day group F1 weanlings.

Lower mean F1 and F2 postnatal survival was noted in the 40 and 60 mg/kg/day groups during PND 0–1 and PND 1–4 (pre-selection) and resulted in lower postnatal survival from birth to PND 4 (pre-selection) compared to the control group. In addition, F2 postnatal survival in the 60 mg/kg/day group was lower than the control group during PND 4 (post-selection) to PND 7 and resulted in lower postnatal survival from PND 4 (post-selection) to PND 21. Postnatal survival of the F1 and F2 pups in the 20 mg/kg/day group was unaffected by parental test substance administration.
There were no test substance-related effects on the number of F1 and F2 pups born, live litter size, or percentage of males at birth at any dosage level.

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

20 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

other: bilateral cataracts

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

60 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: reproductive performance

Critical effects observed:

yes

Lowest effective dose / conc.:

40 mg/kg bw/day (nominal)

System:

eye

Treatment related:

yes

Relevant for humans:

not specified

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

In the 60 mg/kg/day group F1 pups, a test substance-related clinical observation of small stature was noted; no test substance-related clinical observations were noted in F1 pups at 20 and 40 mg/kg/day or F2 pups at any dosage level.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Lower male and female mean offspring body weight gains were noted prior to culling (PND 1-4) in F1 and F2 pups at 40 and 60 mg/kg/day and following culling (PND 4–21) in F1 pups at 40 and 60 mg/kg/day and F2 pups at 60 mg/kg/day compared to the control group and resulted in lower mean body weights in these groups generally throughout the postnatal period.

Sexual maturation:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related effects on balanopreputial separation or vaginal patency in the 20, 40, and 60 mg/kg/day group F1 weanlings.

Lower mean F1 and F2 postnatal survival was noted in the 40 and 60 mg/kg/day groups during PND 0–1 and PND 1–4 (pre-selection) and resulted in lower postnatal survival from birth to PND 4 (pre-selection) compared to the control group. In addition, F2 postnatal survival in the 60 mg/kg/day group was lower than the control group during PND 4 (post-selection) to PND 7 and resulted in lower postnatal survival from PND 4 (post-selection) to PND 21. Postnatal survival of the F1 and F2 pups in the 20 mg/kg/day group was unaffected by parental test substance administration.
There were no test substance-related effects on the number of F1 and F2 pups born, live litter size, or percentage of males at birth at any dosage level.

Dose descriptor:

NOAEL

Generation:

F2

Effect level:

20 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

other: bilateral cataracts

Critical effects observed:

yes

Lowest effective dose / conc.:

40 mg/kg bw/day (nominal)

System:

eye

Treatment related:

yes

Relevant for humans:

not specified

Reproductive effects observed:

no

Lowest effective dose / conc.:

60 mg/kg bw/day (nominal)

Conclusions:

Lower mean body weights and body weight gains were noted for F0 males and F1 males and females at 40 and 60 mg/kg/day. Histopathologic changes consisted of mucosal hyperplasia of non-glandular stomach and urinary bladder noted in F0 males and females at all dosage levels and gross and microscopic changes in the eye (small eyes, enophthalmus, retinal dysplasia, and/or cataract formation), small optic nerve, squamous hyperplasia of the stomach, and mucosal hyperplasia of the urinary bladder noted in F1 males and females in the 20, 40, and/or 60 mg/kg/day groups. Based on these results, a no-observed-adverse-effect level for F0 and F1 parental toxicity was not established in this study.
No adverse effects on F0 and F1 reproductive performance (mating, fertility, copulation and conception indices, estrous cyclicity, and spermatogenic endpoints) were noted. Based on these results, a dosage level of 60 mg/kg/day was considered to be the NOAEL for F0 and F1 reproductive toxicity.
Based on adverse reductions in F1 and F2 postnatal survival, lower offspring body weights and body weight gains, and bilateral cataracts for F1 animals at 40 and 60 mg/kg/day, the NOAEL for developmental/neonatal toxicity was considered to be 20 mg/kg/day.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

60 mg/kg bw/day

Study duration:

chronic

Species:

rat

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Effects on developmental toxicity

Description of key information

In available studies, AITC did not show any evidence of developmental toxicity in pregnant rats, hamsters and rabbits at oral doses up to 18.5, 23.8 and 12.3 mg/kg bw/day, respectively. AITC may be fetotoxic to mice at doses higher than 6.0 mg/kg bw/day, without exhibiting any teratogenic effects.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1973

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

The teratogenic potential of allyl isothiocyanate was evaluated in mice, rats, hamsters and rabbits.

GLP compliance:

not specified

Species:

other: mouse, rat.hamster, rabbit

Strain:

other: Mouse: albino CD-l - Rat: Wistar - Hamster: golden hamsters - Rabbit: Dutch-belted

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

Beginning on Day 6 and continuing daily through Day 10 (hamsters), Day 15 (mice and rats) or Day 18 (rabbits) of gestation.

Dose / conc.:

0.3 mg/kg bw/day (nominal)

Remarks:

mice

Dose / conc.:

1.3 mg/kg bw/day (nominal)

Remarks:

mice

Dose / conc.:

6 mg/kg bw/day (nominal)

Remarks:

mice

Dose / conc.:

28 mg/kg bw/day (nominal)

Remarks:

mice

Dose / conc.:

0.2 mg/kg bw/day (nominal)

Remarks:

rats, hamsters

Dose / conc.:

0.85 mg/kg bw/day (nominal)

Remarks:

rats

Dose / conc.:

4 mg/kg bw/day (nominal)

Remarks:

rats

Dose / conc.:

18.5 mg/kg bw/day (nominal)

Remarks:

rats

Dose / conc.:

1.1 mg/kg bw/day (nominal)

Remarks:

hamsters

Dose / conc.:

5.1 mg/kg bw/day (nominal)

Remarks:

hamsters

Dose / conc.:

23.8 mg/kg bw/day (nominal)

Remarks:

hamsters

Dose / conc.:

0.123 mg/kg bw/day (nominal)

Remarks:

rabbits

Dose / conc.:

0.6 mg/kg bw/day (nominal)

Remarks:

rabbits

Dose / conc.:

2.8 mg/kg bw/day (nominal)

Remarks:

rabbits

Dose / conc.:

12.3 mg/kg bw/day (nominal)

Remarks:

rabbits

No. of animals per sex per dose:

Groups of 23-25 female mice were treated for each dose.
Groups of 25 Wistar rats were treated for each dose.
Groups of25-27 golden hamsters were treated for each dose.
Groups of 11-14 Dutch-belted rabbits were treated for each dose.

Control animals:

yes

yes, sham-exposed

Fetal examinations:

Mice: foetus were examined on day 17 for malformations.
Rats: foetus were examined on day 20 for malformations.
Hamsters: foetus were examined on day 14 for malformations.
Rabbits: foetus were delivered by ceasarean section on day 29..

Remarks on result:

other: maternal effects not specified

Dose descriptor:

NOAEL

Effect level:

18.5 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

not specified

Remarks on result:

other: rats

Dose descriptor:

NOAEL

Effect level:

23.8

Based on:

test mat.

Sex:

not specified

Remarks on result:

other: hamster

Key result

Dose descriptor:

NOAEL

Effect level:

6

Based on:

test mat.

Sex:

not specified

Basis for effect level:

reduction in number of live offspring

Remarks on result:

other: mouse

Sex:

not specified

Remarks on result:

other: Rabbit: not determinable because effects observed at the lowest dose tested (2.8 mg/kg bw/day) were not considered to be compound-related or of toxicological significance

Abnormalities:

no effects observed

Key result

Developmental effects observed:

yes

Lowest effective dose / conc.:

28 mg/kg bw/day

Treatment related:

yes

Relation to maternal toxicity:

developmental effects in the absence of maternal toxicity effects

Dose response relationship:

yes

Relevant for humans:

not specified

The author’s conclusion was that AITC may be fetotoxic to the mouse at doses higher than 6.0 mg/kg bw/day, without exhibiting any teratogenic potency

Conclusions:

AITC did not show any evidence of developmental toxicity in pregnant rats, hamsters and rabbits at oral doses up to 18.5, 23.8 and 12.3 mg/kg bw/day, respectively. AITC may be fetotoxic to mice at doses higher than 6.0 mg/kg bw/day, without exhibiting any teratogenic effects.

Reference 2

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Principles of method if other than guideline:

Groups of pregnant Wistar rats were given 0, 60 or 120 mg/kg body weight of allyl isothiocyanate in corn oil by oral intubation on days 12 or 13 of gestation.

GLP compliance:

not specified

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

Pregnant Wistar rats.

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

Oral intubation on days 12 or 13 of gestation.

Duration of treatment / exposure:

A single oral dose on day 12 o13 of gestation.

Frequency of treatment:

A single oral dose.

Duration of test:

Female were killed on day 22 of gestation.

Dose / conc.:

60 mg/kg bw/day (nominal)

Dose / conc.:

120 mg/kg bw/day (nominal)

Remarks:

Close to the LD 50 for the compound.

No. of animals per sex per dose:

5 to 10 female rats/group

Control animals:

yes, concurrent vehicle

Ovaries and uterine content:

Individual litter weight, litter size, number of deciduomas and number of corpora lutea.

Fetal examinations:

Fetal anomalies were recorded during skeletal and visceral examination.

Mortality:

mortality observed, treatment-related

Description (incidence):

At the highest dose.

Dose descriptor:

dose level:

Effect level:

60 mg/kg bw/day

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Dose descriptor:

dose level:

Effect level:

120 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

mortality

Remarks on result:

other: Dose level very colse to the LD50

Skeletal malformations:

not specified

Description (incidence and severity):

Non-fusion of the fifth sternebra, wavy ribs, retarded ossification and a foruteenth rib.

Dose descriptor:

dose level:

Effect level:

60 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

skeletal malformations

Remarks on result:

other: effects considered minor by the autors

Abnormalities:

effects observed, treatment-related

Localisation:

skeletal: sternum

skeletal: rib

Description (incidence and severity):

Considered minor by the study authors.

Developmental effects observed:

no

Conclusions:

Despite the occurence of maternal toxicity at the high dose, no adverse effect on the foetuses was found.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

6 mg/kg bw/day

Study duration:

chronic

Species:

mouse

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Justification for classification or non-classification

According to the available data, AITC is not classified for the toxicity to reproduction under Regulation (EC) n. 1272/2008.