Exo-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl acrylate

Endpoint summary

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Effects on fertility

Description of key information

IBOA/ target substance

Screening (rat, oral gavage, OECD 422, GLP)

NOAEL general systemic toxicity: 100 mg/kg bw/d due to clinical chemistry effects (increased urea)

NOAEL reproductive toxicity: 100 mg/kg bw/d due to reduced litter size & weight

Metabolite and metabolite donor data

Acrylic Acid, AA (2 -gen, rat, oral, drinking water)

NOAEL general toxicity F0 parents: 2500 ppm due to unspecific effects considered as secondary to unpalatibility of the test item

NOAEL general toxicity F1 parents: 500 ppm due to unspecific effects considered as secondary to unpalatibility of the test item

NOAEL reproductive toxicity F1/F2 pups: 5000 ppm (no effects observed)

NOAEL developmental toxicity F2 pups: 500 ppm due due to variations

Isobornyl Acetate, IBOAC (

NOAEL general toxicity F1: 500 ppm due to unspecific effects considered as secondary to unpalatibility of the test item

NOAEL (general toxicity, rat, oral, gavage: 15 mg/kg bw/d due to liver effects (Isobornyl Acetate, 13 weeks, similar to OECD 408)

chronic

NOAEL general toxicity, rat, oral, drinking water: 61 mg/kg bw/d due to unspecific effects considered as secondary to unpalatibility of the test item (Acrylic Acid, 12 months, comparable to OECD 452)

Link to relevant study records

Reference

Endpoint:

screening for reproductive / developmental toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-06-05 - 2012-07-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD 422, GLP.

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Specific details on test material used for the study:

Identity : Isobornyl acrylate
Alternative name : VISIOMER® IBOA
CAS number : 5888-33-5
EINECS number : 227-561-6

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Italy S.p.A., Calco (Lecco), Italy

- Age at study initiation: (P) Males/females: approximately 8 - 9 wks
- Weight at study initiation: (P) Males: 196.5 - 204.7 g; Females: 166.1 - 189.3 g

- Fasting period before study:
- Housing: Pre mating period: no more than 5 per cage in clear polycarbonate cages measuring 59X39X20 cm with a stainless steel
mesh lid and floor (Techniplast - Gazzada S.a.r.l., Buguggiate, Varese). Each cage tray will hold absorbent material which will be
inspected daily and changed at least three times a week.
During mating period: 1 male to one female per cage in clear polycarbonate cages measuring 36X19X24 cm with a stainless steel
mesh lid and floor (Techniplast - Gazzada S.a.r.l., Buguggiate, Varese). Each cage tray will hold absorbent material which will be
inspected daily.
Pregnant females: will be transferred to individual cages after mating: solid bottomed, breeding cages (Techniplast - Gazzada S.a.r.l.,
Buguggiate, Varese), for the gestation period, birth and lactation.
Suitable nesting material will be provided and will be changed as necessary.
- Diet: ad libitum, commercially available laboratory rodent diet (4 RF 21, Mucedola S.r.l., Via G. Galilei, 4,
20019, Settimo Milanese (MI), Italy)
- Water: ad libitum, supplied via water bottles

- Acclimation period: aproximately 14 days


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

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: A weighted amount of the test item was dissolved in the vehicle (distilled water) and brought to the final volume appropriate for each concentration. The test solutions were prepared daily at room temperature (concentrations of 5, 10, 20 and 40 mg/ml). All test item concentrations and dosages were based on the test item as supplied (dose volume of 10 ml/kg body weight).
Dose volumes for males were calculated according to individual body weight on the first day of treatment and adjusted according to individual body weight at weekly intervals thereafter. Dose volumes for females were calculated according to individual body weight on the first day of treatment and adjusted according to individual body weight at weekly intervals up to positive identification of mating. Dose volumes were adjustced to body weight on Days 0, 7, 14 and 20 post-coitum and on Day 0 post-partum. Thereafter individual dose volumes remained constant. Control animals received the vehicle alone at the same dose volume.

Details on mating procedure:

Mating was monogamous (one male to one female). A vaginal smear was taken from the day after the start of pairing until positive identification of copulation (sperm identification, vaginal plug in situ or copulation plugs found in the cage tray). The female was paired with the same male until positive identification occurred.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Once during week 1 and week 6 of treatment, samples of prepared formulations were analysed for verification of concentration.

Duration of treatment / exposure:

Males
Animals were dosed once a day, 7 days a week, for a minimum of 2 consecutive weeks prior
to pairing and thereafter through the day before necropsy.
Dose volumes were adjusted once per week for each animal according to the last recorded
body weight.

Females
Animals were dosed once a day, 7 days a week, for a minimum of 2 consecutive weeks prior
to pairing and thereafter during pairing, post coitum and post partum periods until Day 3
post partum or the day before sacrifice.
Dose volumes were adjusted once per week for each animal according to the last recorded
body weight. During the gestation period, dose volumes were calculated according to
individual body weight on Days 0, 7, 14 and 20 post coitum and on Day 1 post partum.
Thereafter individual dose volumes remained constant.

Dose / conc.:

25 mg/kg bw/day (nominal)

Dose / conc.:

100 mg/kg bw/day (nominal)

Dose / conc.:

500 mg/kg bw/day (nominal)

No. of animals per sex per dose:

10

Control animals:

yes

Positive control:

no

Parental animals: Observations and examinations:

Once before commencement of treatment and at least once a week thereafter, each animal was given a detailed clinical examination. Each animal was removed from the home cage and observed in an open arena. The tests included observation of changes in gait and posture, reactivity to handling, presence of clonic or tonic movements, stereotypies or bizarre behaviour and effects on the autonomic nervous system (e.g. lachrymation, piloerection, pupil size, unusual respiratory pattern). All observations were recorded for individual animals.
Observed parameters, described by an evaluation scale, are indicated below:

Removal (from cage): Easy, Difficult, Very difficult
Handling reactivity: Normal, Slow, Moderate, Marked
Lachrymation: Absent, Slight, Marked
Palpebral closure: Absent, Slight, Moderate, Marked
Salivation: Absent, Slight, Marked
Piloerection: Absent, Present
Rearing: Absent, Intervals of number of times (i.e. 1-3, 4-7, 8-10)
Spasms: Absent, Tonic spasms, Clonic spasms, Tonic-clonic spasms
Myoclonia: Absent, Present
Mobility impairment: Absent, Slight, Moderate, Marked
Arousal (animal activity): Very slow, Slow, Normal, Moderate, Marked
Vocalisation: Absent, Present
Stereotypies: Absent, Present
Unusual respiratory pattern: Absent, Present
Bizarre behaviour: Absent, Present
Urination: Absent, Intervals of number of times (i.e. 1-3, 4-6)
Defecation: Absent, Intervals of number of times (i.e. 1-3, 4-6)
Tremors: Absent, Present
Gait (one of the following options): Normal
Ataxia (Slight, Moderate, Marked)
Hunched posture (Slight, Moderate, Severe)
Pronation
Forelimbs drag (Slight, Moderate, Marked)
Hindlimbs drag (Slight, Moderate, Marked)

All observed parameters are reported in a group incidence table. Individual data are not
included in this report. Data were reported until Week 6 of the study (all females). All other
data are not tabulated in this report but archived together with all raw data.

Grip strength and sensory reactivity to stimuli

Once during the study, towards the end of treatment, 5 males and 5 females were randomly
selected from each group for evaluation of sensory reactivity to stimuli of different
modalities (e.g. auditory, visual and proprioceptive stimuli) and for assessment of grip
strength. Measurements were performed using a computer generated random order. For
males the tests were performed the day before necropsy and for females on Day 3 post
partum.

Motor activity assessment (MA)

Once during the study, towards the end of treatment, 5 males and 5 females were randomly
selected from each group and the motor activity was measured (for approximately 5 minutes)
by an automated activity recording device. Measurements were performed using a computer
generated random order. For males the tests were performed the day before necropsy and for
females on Day 3 post partum.

Body weight
Males were weighed on the day of allocation to treatment groups, on the day of treatment
commencement, weekly thereafter and at termination.
Females were weighed on the day of allocation to treatment groups, on the day of treatment
commencement, weekly thereafter until pairing and on gestation Days 0, 7, 14 and 20. Dams
were also weighed on Days 1 and 4 post partum.

Oestrous cyclicity (parental animals):

Vaginal smears were taken daily in the morning starting two weeks before pairing until a positive identification of copulation was made. The vaginal smear data was examined to determine the following:
a) anomalies of the oestrous cycle; b) pre-coital interval (i.e., the number of nights paired prior to the detection of mating).

Sperm parameters (parental animals):

Testes were weighted and examined microscopically.

Litter observations:

As soon as possible, after parturition was considered complete (Day 0 or 1 post partum), all pups (live and dead) were counted, sexed and live pups were identified. Live pups were individually weighed on Days 1 and 4 post partum. Pups killed or dying during the lactation period were weighed before the despatch to necropsy. Observations were performed once daily for all litters.

Postmortem examinations (parental animals):

Parental males:
The males were killed after the mating of all females, after 31 days of treatment.

Parental females:
The females with live pups were sacrificed on Day 4 post partum. Two high dose females (nos. 90890061 and 90890079) with total litter loss on Day 1 post partum, were killed on Day 2 post partum.

Necropsy:
The clinical history of the males and females of the parental generation was studied and a detailed post mortem examination was conducted (including examination of the external surface and orifices). Changes were noted, the requisite organs weighed (excluding animals sacrificed for humane reasons or found dead) and the required tissue samples preserved in fixative and processed for histopathological examination.

Females:
All females were examined also for the following:
a) external and internal abnormalities;
b) number of visible implantation sites (pregnant animals);
c) number of corpora lutea (pregnant animals).

Postmortem examinations (offspring):

All pups found dead in the cage or sacrificed for humane reasons were examined for external and internal abnormalities (including gonadal inspection).
All live pups sacrificed at termination were examined for external abnormalities and sex confirmation by gonadal inspection.

Statistics:

Standard deviations were calculated as appropriate. For continuous variables the significance of the differences amongst group means were assessed by Dunnett’s test or a modified t test, depending on the homogeneity of data. Statistical analysis of histopathological findings was carried out by means of the nonparametric Kolmogorov-Smirnov test if n was more than 5. The non-parametric Kruskal-Wallis analysis of variance was used for the other parameters. Intergroup differences between the control and treated groups were assessed by the nonparametric version of the Williams test. The criteria for statistical significance were p<0.05 and p<0.01. The mean value, standard deviations and statistical analysis were calculated from actual values in the computer without rounding off.

Reproductive indices:

Males
Copulatory Index (%) = no. of animals mated x 100
no. of animals paired
Fertility Index (%) = no. of males which induced pregnancy x 100
no. of males paired

Females
Copulatory Index (%) = no. of animals mated x 100
no. of animals paired
Fertility Index (%) = no. of pregnant females x 100
no. of females paired

Males and females
Pre-coital Interval = Mean number of days between pairing and mating

Offspring viability indices:

Pre-birth loss was calculated as a percentage from the formula:
(No. of visible implantations - total litter size at birth ) x 100
No. of visible implantations
Pup loss at birth was calculated as a percentage from the formula:
(Total litter size - live litter size) x 100
Total litter size
Cumulative pup loss on Day 4 post partum was calculated as a percentage from the formula:
(Total litter size at birth - live litter size at Day 4 post partum) x 100
Total litter size at birth
Sex ratios were calculated at birth and on Day 4 post partum and were presented as the
percentage of males per litter.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

salivation

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

slight reduction of food consumption in females

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

slight reduction of food consumption in females

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Treatment-related findings were seen in the glandular stomach of both sexes and in the thymus of the females only .

Other effects:

not examined

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Dose descriptor:

NOAEL

Effect level:

100 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

urinalysis

Critical effects observed:

no

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Cold to touch and apparently no food intake and small in size. An increased number of pups were found dead in the high dose group.

Mortality / viability:

not examined

Body weight and weight changes:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

No milk in stomach and autolysed organs in the abdomen were observed at necropsy in the decedent pups of control and treated groups. No relevant findings were found in pups sacrificed on Day 4 post partum.

Histopathological findings:

not examined

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

100 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

viability

mortality

other: reduced litter size; cumulative pup loss

Critical effects observed:

no

Reproductive effects observed:

not specified

Conclusions:

In this OECD TG 422 GLP study, the toxic effects on Sprague Dawley rats of both sexes after repeated dosing with Isobornylacrylate, as well as any effects of the test item on male and female reproductive function such as gonadal function, mating behaviour, conception, parturition and development of offspring up to Day 4 post partum were evaluated. There was an increase of urea in most of the animals dosed with 500 mg/kg/day (approximately 40%). Statistically significant reduced litter size and litter weight were found in the high dose group compared to controls, starting from birth up to Day 4 post partum.
In addition, the percentage of cumulative pup loss on Day 4 post partum, starting from the total litter size of birth, was increased in the high dose group. On the basis of these results the NOAEL (No Observed Adverse Effect Level) for both general toxicity and reproduction/developmental toxicity was determined to 100 mg/kg/day for males and females.

Executive summary:

In this OECD TG 422 GLP study, both potential repeated dose toxicity and potential reproduction / developmental toxicity of Isobornyl acrylate in Sprague Dawley rats was evaluated. Isobornyl acrylate was administered orally, by gavage, at the dosages of 25, 100 and 500 mg/kg/day. The treatment schedule included 2 weeks before pairing, during pairing, post coitum and post partum periods up to Day 3 post partum. Animals were administered for approximately 5 and 6 weeks for males and females, respectively.The parental animals were monitored for daily clinical signs, weekly neurotoxicity assessment, body weight, food consumption and clinical pathology investigations. The dams were allowed to give birth and rear their offspring until Day 4 post partum.

The following results were obtained in the study:

Daily clinical signs: salivation was the relevant sign detected in both sexes of the mid- and high dose groups.

Clinical pathology: no findings of toxicological significance were recorded in the

haematological investigation. At clinical chemistry evaluation, increased values of urea were noted in the high dose group of both sexes. At urinalyses high proteinuria was recorded in mid- and high dose males, with a dose related trend.

Reproductive / developmental parameters: no relevant differences were found in terms of mating performance including the pre-coital interval (number of days paired up to sperm positive day), the copulatory index (calculated as the percentage of animals mated respect to those paired) and the fertility index, these last two parameters with percentages of 100% in all groups.

All pregnant females in the groups, including controls, had comparable length of gestation period and gave births. Furthermore, sex ratio calculated as the percentage of males in the litter did not differ between the groups.

However, significant differences were found in terms of total litter size and litter weight in the high dose group compared to controls, from birth to Day 4 post partum.

In addition, the percentage of cumulative pup loss on Day 4 post partum, starting from the total litter size at birth, was increased in the high dose group.

No relevant findings were detected in pups sacrificed at term, nor in those found dead in all groups.

Organ weights: increased kidneys weight in mid- and high dose males and a decrease of thymus weight in high dose females were found.

Macroscopic and microscopic observations: treatment-related changes were found in

stomach of mid- and high dose animals of both sexes and in the thymus of mid- and high dose females only.

 

On the basis of the results obtained in the study, the NOAEL (No Observed Adverse Effect Level) for both general toxicity and reproduction/developmental toxicity was determined to 100 mg/kg/day for males and females.

NOTE: Any of data in this dataset are disseminated by the European Union on a right-to-know basis and this is not a publication in the same sense as a book or an article in a journal. The right of ownership in any part of this information is reserved by the data owner(s). The use of this information for any other, e.g. commercial purpose is strictly reserved to the data owners and those persons or legal entities having paid the respective access fee for the intended purpose.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

100 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Klimisch 1 (Guideline study, GLP)

Additional information

Reproductive toxicity of IBOA has been investigated on a screening level in a OECD 422 combined repeated dose and reproductive toxicity study.

Existing data gaps are covered using the read across approach based on rapid hydrolysis mentioned in chapter1 of the attached read across justification, considering the ECHA guidance on Read Across (RAAF, ECHA 2017a). For this endpoint, the relatively short half-life of IBOA as parent ester leads to the conclusion that systemic effects after repeated exposure are mainly driven by the products of ester hydrolysis, namely Acrylic Acid, AA, and Isoborneol, IBO. Local effects after inhalation are determined by local release of AA. Butyl Acrylate, BA, and Isobornyl Acetate, IBOAc, are known to hydrolyse also rapidly so that these substances serve as donor substances for the primary metabolites AA and IBO.Qualitatively, this aspect can be categorized as “(Bio) transformation to common compound(s)”. The read across approach is done with a high level of confidence.

Target substance

IBOA

In an OECD TG 422 GLP study (see Endpoint Summary "Repeated dose toxicity" for study details), there was an increase of urea of approximately 40% in most of the animals dosed with 500 mg/kg/day. Statistically significant reduced litter size and litter weight were found in the high dose group compared to controls, starting from birth up to Day 4 post partum. In addition, the percentage of cumulative pup loss on Day 4 post partum, starting from the total litter size of birth, was increased in the high dose group. On the basis of these results the NOAEL (No Observed Adverse Effect Level) for both general toxicity and reproduction/developmental toxicity was determined to 100 mg/kg/day for males and females. 

On the basis of the results obtained in the study, the NOAEL (No Observed Adverse Effect Level) for both general toxicity and reproduction/developmental toxicity was determined to100 mg/kg/day for males and females (RTC, 2012).

 

Metabolites and Metabolite Donor Substances

AA

Groups of 25 male and 25 female Wistar rats (for both F0 and F1 generations) received acrylic acid (AA) in the drinking water at concentrations of 0 (control), 500, 2500 and 5000 ppm for at least 70 days prior to mating, through mating, gestation, lactation and to weaning in a two-generation reproduction toxicity study.

The study continued through to weaning of the F2 offspring at 21 days of age.

AA had no adverse effects on fertility and reproductive performance of the parent rats at doses up to 5000 ppm. General systemic toxicity was apparent with reduced body weights, food and water consumption in F0 parents at 5000 ppm and in FI parents at 2500 and 5000 ppm; the only treatment-related pathological finding was a minimal hyperkeratosis of the limiting ridge of the forestomach with a minimal oedema of the submucosa of the glandular stomach in both parental generations at 5000 ppm. Dose-related signs of developmental toxicity were detected in F1 and F2 pups at 2500 and 5000 ppm in the form of retarded growth and some delay in the eye/auditory canal opening in F2 pups, but there was no evidence that AA had an adverse influence on pup morphology. Thus, the no-observed-adverse-effect level (NOAEL) is 5000 ppm for fertility and reproductive performance of the parents, 2500 ppm (F0 parents) or 500 ppm (Fl parents) for general systemic toxicity and 500 ppm for developmental toxicity.” The mentioned NOAEL for developmental toxicity effects refers to the F2 generation and is in the same dose level as the respective NOAEL for systemic toxicity of the relevant parent generation F1. Moreover, these effects (“formof retarded growth and some delay in the eye/auditory canal opening in F2 pups”) can be understood as variation.

Effects on developmental toxicity

Description of key information

IBOA/ target substance

Subacute

NOAEL general systemic toxicity, rat, oral gavage: 100 mg/kg bw/d due to clinical chemistry effects (increased urea; IBOA, OECD 422, GLP)

Metabolite and metabolite donor data

subchronic

NOAEL general toxicity, rat, oral, drinking water: 83 mg/kg bw/d due to unspecific effects considered as secondary to unpalatibility of the test item (Acrylic Acid, 90d, pre-guideline)

NOAEL general toxicity, rat, oral, drinking water: 84/111 mg/kg bw/d due to unspecific effects considered as secondary to unpalatibility of the test item (Butyl Acrylate, 90d, similar to OECD 408)

NOAEL (general toxicity, rat, oral, gavage: 15 mg/kg bw/d due to liver effects (Isobornyl Acetate, 13 weeks, similar to OECD 408)

chronic

NOAEL general toxicity, rat, oral, drinking water: 61 mg/kg bw/d due to unspecific effects considered as secondary to unpalatibility of the test item (Acrylic Acid, 12 months, comparable to OECD 452)

In an OECD 422 GLP study with isobornyl acrylate in rats, the NOAEL for development of offspring was at 100 mg/kg/day which was the NOEL for maternal toxicity as well.
Supportingly, there is extensive information available for structurally analogous acrylate esters. The absence of a teratogenic potential was demonstrated (amongst others) in teratogenicity studies in rats and mice (OECD 414) for butyl acrylate and n-ethylhexyl acrylate.
In conclusion, based on studies in experimental animals, there is no evidence for toxicity of isobornyl acrylate to the reproductive system.

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2012-06-05 - 2012-07-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD 422, GLP.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other: OECD 422 screening study

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Specific details on test material used for the study:

Identity : Isobornyl acrylate
Alternative name : VISIOMER® IBOA
CAS number : 5888-33-5
EINECS number : 227-561-6

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Italy S.p.A., Calco (Lecco), Italy

- Age at study initiation: (P) Males/females: approximately 8 - 9 wks
- Weight at study initiation: (P) Males: 196.5 - 204.7 g; Females: 166.1 - 189.3 g

- Fasting period before study:
- Housing: Pre mating period: no more than 5 per cage in clear polycarbonate cages measuring 59X39X20 cm with a stainless steel
mesh lid and floor (Techniplast - Gazzada S.a.r.l., Buguggiate, Varese). Each cage tray will hold absorbent material which will be
inspected daily and changed at least three times a week.
During mating period: 1 male to one female per cage in clear polycarbonate cages measuring 36X19X24 cm with a stainless steel
mesh lid and floor (Techniplast - Gazzada S.a.r.l., Buguggiate, Varese). Each cage tray will hold absorbent material which will be
inspected daily.
Pregnant females: will be transferred to individual cages after mating: solid bottomed, breeding cages (Techniplast - Gazzada S.a.r.l.,
Buguggiate, Varese), for the gestation period, birth and lactation.
Suitable nesting material will be provided and will be changed as necessary.
- Diet: ad libitum, commercially available laboratory rodent diet (4 RF 21, Mucedola S.r.l., Via G. Galilei, 4,
20019, Settimo Milanese (MI), Italy)
- Water: ad libitum, supplied via water bottles

- Acclimation period: aproximately 14 days


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

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: A weighted amount of the test item was dissolved in the vehicle (distilled water) and brought to the final volume appropriate for each concentration. The test solutions were prepared daily at room temperature (concentrations of 5, 10, 20 and 40 mg/ml). All test item concentrations and dosages were based on the test item as supplied (dose volume of 10 ml/kg body weight).
Dose volumes for males were calculated according to individual body weight on the first day of treatment and adjusted according to individual body weight at weekly intervals thereafter. Dose volumes for females were calculated according to individual body weight on the first day of treatment and adjusted according to individual body weight at weekly intervals up to positive identification of mating. Dose volumes were adjustced to body weight on Days 0, 7, 14 and 20 post-coitum and on Day 0 post-partum. Thereafter individual dose volumes remained constant. Control animals received the vehicle alone at the same dose volume.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Once during week 1 and week 6 of treatment, samples of prepared formulations were analysed for verification of concentration.

Details on mating procedure:

Mating was monogamous (one male to one female). A vaginal smear was taken from the day after the start of pairing until positive identification of copulation (sperm identification, vaginal plug in situ or copulation plugs found in the cage tray). The female was paired with the same male until positive identification occurred.

Duration of treatment / exposure:

Males
Animals were dosed once a day, 7 days a week, for a minimum of 2 consecutive weeks prior
to pairing and thereafter through the day before necropsy.
Dose volumes were adjusted once per week for each animal according to the last recorded
body weight.

Females
Animals were dosed once a day, 7 days a week, for a minimum of 2 consecutive weeks prior
to pairing and thereafter during pairing, post coitum and post partum periods until Day 3
post partum or the day before sacrifice.
Dose volumes were adjusted once per week for each animal according to the last recorded
body weight. During the gestation period, dose volumes were calculated according to
individual body weight on Days 0, 7, 14 and 20 post coitum and on Day 1 post partum.
Thereafter individual dose volumes remained constant.

No. of animals per sex per dose:

10

Control animals:

yes

Maternal examinations:

yes

Ovaries and uterine content:

yes

Fetal examinations:

yes

Statistics:

Standard deviations were calculated as appropriate. For continuous variables the significance of the differences amongst group means were assessed by Dunnett’s test or a modified t test, depending on the homogeneity of data. Statistical analysis of histopathological findings was carried out by means of the nonparametric Kolmogorov-Smirnov test if n was more than 5. The non-parametric Kruskal-Wallis analysis of variance was used for the other parameters. Intergroup differences between the control and treated groups were assessed by the nonparametric version of the Williams test. The criteria for statistical significance were p<0.05 and p<0.01. The mean value, standard deviations and statistical analysis were calculated from actual values in the computer without rounding off.

Details on maternal toxic effects:

Maternal toxic effects:yes

Dose descriptor:

NOAEL

Effect level:

100 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

urinalysis

Abnormalities:

no effects observed

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Dose descriptor:

NOAEL

Remarks:

developmental toxicity

Effect level:

500 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

other: no adverse effects observed

Abnormalities:

no effects observed

Developmental effects observed:

not specified

Conclusions:

Isobornyl acrylate did not show developmental toxicity via oral gavage to rats at doses as high as 500 mg/kg bw/day in the decribed reproductive/developmental toxicity screening study according to OECD 422.

Executive summary:

Isobornyl acrylate did not show developmental toxicity via oral gavage to rats at doses as high as 500 mg/kg bw/day in the decribed reproductive/developmental toxicity screening study according to OECD 422 (for more details please also see IUCLID chapter 7.5.1 and 7.8.1). There were no signs of neonatal toxicity or external malformations at doses of 500 mg/kg bw/day.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

100 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Klimisch 1 (Guideline study, GLP)

Additional information

Reproductive toxicity of IBOA has been investigated on a screening level in a OECD 422 combined repeated dose and reproductive toxicity study.

Existing data gaps are covered using the read across approach based on rapid hydrolysis mentioned in chapter1 of the attached read across justification, considering the ECHA guidance on Read Across (RAAF, ECHA 2017a). For this endpoint, the relatively short half-life of IBOA as parent ester leads to the conclusion that systemic effects after repeated exposure are mainly driven by the products of ester hydrolysis, namely Acrylic Acid, AA, and Isoborneol, IBO. Local effects after inhalation are determined by local release of AA. Butyl Acrylate, BA, and Isobornyl Acetate, IBOAc, are known to hydrolyse also rapidly so that these substances serve as donor substances for the primary metabolites AA and IBO.Qualitatively, this aspect can be categorized as “(Bio) transformation to common compound(s)”. The read across approach is done with a high level of confidence.

In an OECD TG 422 GLP study with isobornyl acrylate in rats, the NOAEL for development of offspring and maternal toxicity was 100 mg/kg/d.

Supportingly, there is extensive information available for structurally analogous acrylate esters.

In a study equivalent to OECD guideline no. 414, rats were given whole-body inhalation exposures to n-butyl acrylate at target concentrations up to 300 ppm (1.57 mg/L) for 6 hr/day, during days 6 to 20 of gestation. Maternal toxicity was observed at 100 ppm. The NOAEC for fetotoxicity was at 100 ppm (0.52 mg/L) and the NOAEC for teratogenicity at 300 ppm (1.57 mg/L).

In the identically performed study with ethylhexyl acrylate, the NOAEC for maternal toxicity was 75 ppm (0.56 mg/L) and the NOAEC for teratogenicity was 100 ppm (0.75 mg/L).

Again with butyl acrylate, an oral study teratogenicity study in mice was performed at day 5 to 20 of gestation with doses up to 4000 mg/kg/d. The NOAEL for developmental toxicity is 1000 mg/kg based on diminished fetal body weights at 1500 mg/kg and above. The NOAEL for teratogenicity is 2000 mg/kg based on malformations observed at higher doses.

In conclusion, based on studies in experimental animals, there is no evidence for toxicity of isobornyl acrylate to the reproductive system.

Justification for selection of Effect on developmental toxicity: via oral route:
In an OECD 422 study with Isobornyl acrylate in rats, no critical effects concerning developmental toxicity were observed.

Justification for classification or non-classification

According to the criteria as of directive 1272/2008/EC, no classification is warranted.