Isooctyl acrylate

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study by an experienced laboratory

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Internal laboratory guideline according to GLP

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Isooctyl acrylate

EC Number:

249-707-8

EC Name:

Isooctyl acrylate

Cas Number:

29590-42-9

Molecular formula:

C11H20O2

IUPAC Name:

2-methylheptyl prop-2-enoate

Details on test material:

- Name of test material:
2-Propenoic Acid, Isooctyl Ester (IOA)

- Substance type:
Highly pure material

- Physical state:
Liquid

- Analytical purity: 99.75%
- Stability under test conditions:
Stable at room temperature

- Storage condition of test material:
Stored at room temperature

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River
Laboratories, Inc. (Kingston, New York)

- Age at study initiation: 12 weeks

- Weight at study initiation:

The males for Groups 1 through 4 weighed between 211.9 and 249.2 g; the femalesweighed between 140.3 and 165.6g. The animals for Groups 5 and 6 weighed between 246.5 and 271.6 g (males)and 144.6 and 169.6 g (females).


- Fasting period before study: NA

- Housing: Individual housing

- Use of restrainers for preventing ingestion (if dermal): Yes

- Diet (e.g. ad libitum): ad libitum

- Water (e.g. ad libitum): ad libitum

- Acclimation period:
Forty-six males and 44 females were received and acclimated for Phase I; 23 males and 23 females were received and acclimated for Phase II. One female from Phase I died before the randomization. The remaining animals in Phase I and animals in Phase II were examined on April 16, 1992, and May 28, l992, respectively, by the
laboratory animal veterinarian and found to be suitable for study consideration. Animals were randomized for assignment to groups (10/sex/group). Animals not selected for the study were sacrificed and discarded.

ENVIRONMENTAL CONDITIONS

- Temperature (°C): 19 to 25 deg C.

- Humidity (%): 50 +/- 20%

- Air changes (per hr): NA

- Photoperiod (hrs dark / hrs light): 12hours/12hours

Administration / exposure

Route of administration:

dermal

Vehicle:

acetone

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:

VEHICLE
Acetone, test compound is not soluble or stable in water

- Concentration in vehicle: 0%, 1%, 7.5%, 5%, 15% 25%
- Amount of vehicle (if gavage): 100ul/day for 2 weeks prior to mating.

- Lot/batch no. (if required): NA
- Purity: high grade solvent


TEST SITE
- Area of exposure: dorsal intrascapular area of trunk

- % coverage: test material was applied uniformly

REMOVAL OF TEST SUBSTANCE

- Washing (if done):

- Time after start of exposure:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 100 ul
- Concentration (if solution): 0 to 25%
- Constant volume or concentration used: constant volume

VEHICLE
- Justification for use and choice of vehicle (if other than water): Solubility and stability in acetone better than water

- Amount(s) applied (volume or weight with unit): 100 ul
- Concentration (if solution): 0 to 25% of test compound
- Lot/batch no. (if required): NA
- Purity:
USE OF RESTRAINERS FOR PREVENTING INGESTION: Yes

Details on mating procedure:

Each female was paired with one male from the same group for a maximum of 14 days. Vaginal examinations were done daily during cohabitation and the presence of sperm in the vaginal smear or a copulatory plug was considered evidence of positive mating. The day when such evidence was found was considered Day 0 of gestation, and the female was then housed individually. When mating was confirmed, the males and females were separated. Females that showed no evidence of mating were placed in nesting boxes after completion of the mating period.

- M/F ratio per cage:
- Length of cohabitation: UP to 14 days
- Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy: Vaianal smear or copulatory plug

- After ... days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: [no / yes (explain)]
- After successful mating each pregnant female was caged (how):
- Any other deviations from standard protocol:

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Homogenecity was determined for the 1%, 15%, and 25% concentrations. Samples taken from the top, middle, and bottom of the dose preparations were analyzed for test material content.

Duration of treatment / exposure:

Each animal was exposed to the test materialor carrier for at least 6 hours/day at a dose volume of 100 uL/day for 2 weeks before mating and throughout mating until sacrifice.

Frequency of treatment:

Daily

Details on study schedule:

Each female was paired with one male from the same group for a maximum of 14 days. Vaginal examinations were done daily during cohabitation, and the presence of sperm in the vaginal smear or a copulatory plug was considered evidence of positive mating. The day when such evidence was found was considered Day 0 of gestation, and the female was then housed individually. When mating was confirmed, the males and females were separated. Females that showed no evidence of mating were placed in nesting boxes after completion of the mating period.

Doses / concentrations

Remarks:

Doses / Concentrations:
0%, 1%, 7.5%, 5%, 15% , 20/25%
Basis:
nominal conc.

No. of animals per sex per dose:

10

Control animals:

yes

Details on study design:

- Dose selection rationale: Toxicity screens

Positive control:

None

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule:Daily
DETAILED CLINICAL OBSERVATIONS: Yes / No / No data

The animals were observed twice daily (a.m. and p.m.) for mortality,moribundity,and signs of poor health or abnormal behavior. Females were observedfor signs of abortion,excessive bleeding, premature delivery,or difficult and prolonged parturition. Each animal was removed from its cage and examined when body weights were recorded.

BODY WEIGHT: Yes
There were no significant differences in body weight changes during pre- and postmating for males or during premating for females. Body weight gains were significantly higher for females at 20%/25% IOA during Day 0 to 20 of gestation and Days 0 to 4 of lactation; however, these differences are not considered to be toxicologically important.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
Individual food consumption data were recorded weekly during the premating phase. Food consumption was measured for mated females for presumed Gestation Days 0-7, 7-14, and 14-20, and for femalesthat deliveredlittersfor Lactation Days 0 through 4.

- Time schedule for examinations:

Hematology and clinical chemistry parameters were evaluatedf or all adult males before scheduled sacrifice. The animals were fasted overnight, then anesthetized with ketamine and blood was collected from the retro-orbital plexus. After the pup necropsies were completed,the parental animals were anesthesized with sodium pentobarbital, weighed, exsanguinated, and necropsied. The necropsy included a macroscopic examination of the external surface of the body; all orifices;the cranial cavity; the external and cut surfacesof the brain and spinal cord; and the cervical, thoracic,and abdominal viscera.:

Oestrous cyclicity (parental animals):

NA

Sperm parameters (parental animals):

NA

Litter observations:

STANDARDISATION OF LITTERS

Birth (Day 0 of Lactation). As soon as possibleafter birth, the sex of each pup was determined,and the litter size (totalnumber of pups born live or found dead) was recorded. Each live pup was examined for external abnormalities and weighed.

- Performed on day 4 postpartum: Yes

Day 4. The sex of each pup was determined,and the litter size {numberof live pups) was recorded. The pups were examined for external abnormalities and weighed individually before sacrifice. Pups were sacrificed using B euthanasia®-D euthanasia solution;examined for cervical,thoracic,or abdominal visceral
abnormalities;then discarded. Abnormal tissues were preserved in
10% phosphate-buffered formalin [exceptf or kidney lesions for pups from three litters.

PARAMETERS EXAMINED

As soon as possible after birth, the sexa of each pup was determined, and the litter size (total number of pups born live or found dead) was recorded. Each live pup was examined for external abnormalities and weighed.


The following parameters were examined in [F1 / F2 / F3] offspring:
[number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities, other:]

GROSS EXAMINATION OF DEAD PUPS:
Whenever possible,dead pups were examined macroscopically for cervical,thoracic, and abdominal visceral abnormalities and congenital abnormalities and then discarded.

Whenever possible, dead pups were examined macroscopically for cervical, thoracic, and abdominal visceral abnormalities and congenital abnormalities and then discarded.

Postmortem examinations (parental animals):

SACRIFICE

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring not selected as parental animals and all F2 offspring were sacrificed at [#?] days of age.
- These animals were subjected to postmortem examinations (macroscopic and/or microscopic examination) as follows:
GROSS NECROPSY
- Gross necropsy consisted of [external and internal examinations including the cervical, thoracic, and abdominal viscera.]
HISTOPATHOLOGY / ORGAN WEIGTHS
The tissues indicated in Table [#] were prepared for microscopic examination and weighed, respectively.

Statistics:

One-way ANOVA was used to analyze continuous data such as body weights, body weight changes, food consumption, clinical chemistry and hematology values {except red blood cell morphology}, litter data, and length of gestation. Reproduction
indices {number inseminated,numberpregnant,female fertility,and gestation index} were analyzed by the Cochran-Armitage test (Thakur, et. al., 1985} for trend and departure and by a Fisher-Irwin exact test (Thakur, et. al., 1985). One-way analysis of covariance [ANCOVA (Winer,1971b)] was used to analyze the pup body weights (male and female), with the number of pups in the litter as the covariate.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

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:

not specified

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS)

There were no significant differences in food consumption during premating for males or during premating or gestation for females. Food consumption was significantly higher for females treated with 20% IOA during lactation (16% higher than those of controls); however, this is not considered to be toxicologically important.
Week I body weights were significantlylower for females at 20%/25% IOA. However, no significant differences were noted at Week 2 and there were no other significant differences in body weights during premating,gestation,or lactation. Therefore,the significant difference at Week 1 was not consideredt o be toxicologically important. There were no significant differences for males pre- or postmating.

TEST SUBSTANCE INTAKE (PARENTAL ANIMALS): na

REPRODUCTIVE FUNCTION: ESTROUS CYCLE (PARENTAL ANIMALS): Female Data. There were no test material-related significant differences observed for mating or female fertility indices, mean days to mate, or length of gestation.

REPRODUCTIVE FUNCTION: SPERM MEASURES (PARENTAL ANIMALS)

Male Data. There were no test material-related differences for male fertility based on the percent of pregnant females.

REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS)

No effects reported

There were no test material-related changes for terminal body weights,absolute organ weights, organ-to-body weight percentages or macroscopic or microscopic findings
OTHER FINDINGS (PARENTAL ANIMALS): Significant dermal irritation at 25% concentration

Effect levels (P0)

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 20 other: %

Based on:

test mat.

Sex:

male/female

Basis for effect level:

clinical signs

mortality

dermal irritation

body weight and weight gain

haematology

clinical biochemistry

organ weights and organ / body weight ratios

gross pathology

histopathology: non-neoplastic

histopathology: neoplastic

reproductive function (sperm measures)

reproductive performance

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Sexual maturation:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

no effects observed

Details on results (F1)

VIABILITY (OFFSPRING): Normal
CLINICAL SIGNS (OFFSPRING) Normal
GROSS PATHOLOGY (OFFSPRING): Normal

Effect levels (F1)

Key result

Dose descriptor:

NOEL

Generation:

F1

Effect level:

ca. 20 other: %

Sex:

female

Basis for effect level:

other: overall effects including clinical signs; mortality; body weight; food consumption and compound intake; food efficiency; water consumption and compound intake; gross pathology; organ weights; histopathology;

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

Interpretation of results: negative

Criteria used for interpretation of results: expert judgment

Applicant's summary and conclusion

Conclusions:

When IOA was administereddermallyto rats in concentrationsof 1%, 7.5%, 15%, and 20%, the no-observable-effect level for effects on reproductive performance and growth and development of offspring was 20%. There was no overt material toxicity
at the highest dose level tested (20/,IOA). Minimal increases in aspartate aminotransferase and alanine aminotransferase were noted in animals given 20% IOA. Severe dermal irritation precluded dosing at higher dose levels (i.e., 25% IOA).

Executive summary:

The purpose of this study was to provide information concerning toxic effects and effects of 2-PropenoicAcid, Isooctyl Ester (IOA), on reproductive performance following repeated dosing in the rat.

Animals were assigned at random to six groups (10/sex/group) that received 0%,1.0%, 7.5%, 15%, and 20%/25% IOA applied to the intact dorsal dermal surface at a dose volume of 100 uL/day. Due to a notable irritation at 25% after 1 week of dosing, the dose was lowered to 20% for the remainder of the study. Animals in the control groups received acetone at a dose volume equal to that applied to the test animals. Antemortem data (i.e.,clinical observations,dermal observations,body weights, and food consumption, reproduction data, and litter data were recorded. Clinical chemistry and hematology parameters were evaluated for all adult males. All adults were examined macroscopically,and selected tissues were weighed and preserved in 10% phosphate-buffered formalin. Tissues from the control and high-dose groupswere sectioned,stained,and examined microscopically. There were no test material-related clinical observations or adverse effects on body weights, body weight changes, food consumption,or reproductive performance.

Dermal irritation was noted at 20% and included slight to moderate erythema and slight desquamation for males and slight erythema, slight to moderate desquamation, and slight fissuring for females. Minimally higher aspartate aminotransferase and alanine aminotransferase was present at 20% IOA. There were no test material-related changes for terminal body weights, absolute organ weights, organ-to-body weight percentages or macroscopic or microscopic findings. The no-observable-effect level for effects on reproductive performance and growth and development of offspring was 20% IOA. There was no overt material toxicity at the highest dose level tested (20% IOA). Minimal increases in aspartate aminotransferase and alanine aminotransferase were noted in animals given 20% IOA. Severe dermal irritation precluded dosing at higher dose levels (i.e., 25% IOA).