2-Propenoic acid, 2-propylheptyl ester

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records

Reference

Endpoint:

two-generation reproductive toxicity

Remarks:

based on test type (migrated information)

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2008-04-21 to 2009-09-09

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-study according to OECD guideline 416. Read across was performed with methyl acrylate. Please refer to IUCLID section 13 for read across justification.

Qualifier:

according to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

Version / remarks:

2001

Deviations:

yes

Principles of method if other than guideline:

Anogenital distance, a triggered end point as per test guidelines, was not measured in the F2 pups because there were no significant effects observed on F1 sex ratio or age at vaginal opening or preputial separation.

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

other: Crl:CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories Inc. (Portage, Michigan)
- Age at study initiation: (P) 6 wks; (F1) x wks
- Mean weight at study initiation: (P) Males: 176.9 ± 6.3 g; Females: 131.0 ± 5.8 g; (F1) Males: 169.7 ± 22.8 g; Females: 143.6 ± 16.8 g
- Fasting period before study: no
- Housing: singly in stainless steel cages, except during breeding (one male and female)
- Use of restrainers for preventing ingestion (if dermal): no
- Diet: LabDiet Certified Rodent Diet #5002 (PMI Nutrition International, St. Louis, Missouri), ad libitum
- Water: drinking water from the municipal water source, ad libitum
- Acclimation period: at least one week

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 1
- Humidity (%): 40 - 70
- Air changes (per hr): 12-15
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

inhalation: vapour

Type of inhalation exposure (if applicable):

whole body

Vehicle:

other: air

Details on exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: 14.5 m^3 inhalation exposure chambers under dynamic airflow conditions
- System of generating aerosols: generated by using the J-tube method of Miller et al.
- Temperature, humidity in air chamber: 22 ± 2°C, 40 to 60%
- Air flow rate: 2900 L/min
- Method of particle size determination:
- Treatment of exhaust air: All test chamber exhaust was passed through an activated charcoal bed to remove test material from the exhaust stream.

TEST ATMOSPHERE
- Brief description of analytical method used: An IR spectrophotometer was used to evaluate the chamber concentrations.
- Samples taken from breathing zone: yes, once per hour

Details on mating procedure:

- M/F ratio per cage: 1/1
- Length of cohabitation: until mating occurred or two weeks elapsed
- Proof of pregnancy: vaginal plug, sperm in vaginal smear referred to as day 0 of pregnancy
- Further matings after one unsuccessful attempt: no
- After successful mating each pregnant female was caged (how): in stailess steel cages

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The chamber concentrations of methyl acrylate, measured approximately in the center of the breathing zone of the animals, were determined at least once per hour with a Miran 1A infrared (IR) spectrophotometer (Foxboro/Wilks, South Norwalk, Connecticut) and reported by a strip chart recorder. The IR spectrophotometer was calibrated and a standard curve was compiled prior to and at the midpoint of the study, using air standards prepared by vaporizing measured volumes of methyl acrylate into Tedlar sample bags (Series 233, SKC, Eighty Four, Pennsylvania) along with the metered volumes of dry, compressed air. Chamber concentrations during the exposures were interpolated using the standard curve. The analytical system was checked prior to each exposure with a methyl acrylate standard gasbag of known concentration. The CAMILE TG 4 Data Acquisition and Control System toggled the IR spectrophotometer between the chambers for concentration sampling. The nominal concentration of the test material in each chamber was estimated based on the amount of test material used and the total airflow through the chamber. Prior to the start of the study, each of the chambers was checked to ensure that a uniform distribution of vapor was present throughout the breathing zone of the animals.

Duration of treatment / exposure:

6 hours/day, 7 days/week for approximately 10 weeks prior to breeding and continuing through breeding (two weeks), gestation (three weeks) and lactation (four weeks) for each of two generations

Frequency of treatment:

Daily. Maternal rats were not exposed to methyl acrylate after Gestation Day (GD) 20 through Lactation Day (LD) 4 in order to allow for parturition and initiation of lactation.

Details on study schedule:

- F1 parental animals not mated at least until 10 weeks after selected from the F1 litters.
- Selection of parents from F1 generation when pups were 28 days of age.
- Age at mating of the mated animals in the study: approx. 13 weeks

Remarks:

Doses / Concentrations:
0, 5, 25, and 75 ppm
Basis:
other: target concentration

Remarks:

Doses / Concentrations:
0, 5.3 ± 0.2, 24.9 ± 0.4, and 73.4 ± 1.8 ppm
Basis:
nominal conc.

Remarks:

Doses / Concentrations:
0, 5.3 ± 0.2, 25.7 ± 0.3, and 75.4 ± 0.6 ppm (corresponding to approx. 0, 0.019, 0.092, and 0.269 mg/L)
Basis:
analytical conc.
Recalculation based on the equation c(mg/m3) = molar mass (g) / molar volume (L) x c(mL/m3) with molecular weight (86.09 g/mol) and molar volume (24.1 L at 20 °C and 1013 hPa) [DFG, 2005]

No. of animals per sex per dose:

27/sex/dose

Control animals:

yes, sham-exposed

Details on study design:

- Dose selection rationale: Two other developmental toxicity tests (Saillenfait et al. 1999; Carney et al., 2008) with methyl acrylate were used for dose selection.

Positive control:

None

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: weekly (males and females) throughout breeding period; mated females on GD 0, 7, 14, 21 and LD 0, 1, 4, 7, 14, 21, 28

BODY WEIGHT: Yes
- Time schedule for examinations: males and females were weighed weekly; mated females on GD 0, 7, 14, 21 and on LD 1, 4, 7, 14, 21, 28

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
- Time schedule: weekly (males and females) throughout breeding period; mated females on GD 0, 7, 14, 21 and on LD 1, 4, 7, 14, 21, 23, 26, 28

Oestrous cyclicity (parental animals):

Vaginal lavage samples were collected daily for all P1 and P2 females for three weeks prior to mating and during cohabitation until each female was sperm or plug positive or until the two-week mating period elapsed. Lavage samples were collected by gently irrigating the vagina with water and transferring loosely adherent vaginal cells to a slide with a pipette. Vaginal lavage slides were examined to determine estrous cycle length and pattern. Additionally, on the day of scheduled necropsy, the stage within the estrous cycle was determined for all P1 and P2 female rats.

Sperm parameters (parental animals):

Parameters examined in P1, P2 male parental generations:
testis weight, epididymis weight, sperm count in testes, sperm count in epididymides, enumeration of cauda epididymal sperm reserve, sperm motility, sperm morphology

Litter observations:

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

PARAMETERS EXAMINED
The following parameters were examined in P1 / P2 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities

GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was not determined for pups born or found dead.

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals were sacrificed after completion of their respective mating period.
- Maternal animals: All surviving animals were sacrificed after weaning of their litters or at least 24 days after the end of the mating period for females not producing a litter.

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

HISTOPATHOLOGY / ORGAN WEIGHTS
Weights of the ovaries, uterus (with oviducts and cervix), testes, epididymides, seminal vesicles with coagulating glands (and fluids), prostate, brain, pituitary (weighed after fixation), liver, kidneys, adrenal glands, spleen, thyroid with parathyroids (weighed after fixation) were recorded, and the organ-to-body weight ratios calculated. In addition, weights of the left testis and left cauda epididymis were collected for use in calculating sperm count parameters.

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring not selected as parental animals and all F2 offspring were sacrificed at 28 days of age.

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

HISTOPATHOLOGY / ORGAN WEIGTHS
Representative sample of grossly abnormal tissues and any known target organs were collected from all weanlings at the scheduled necropsy. In addition, one of the three pups/sex/litter was randomly selected from those examined grossly for the collection of brain, spleen, uterus, and thymus weights. Organ-to-body weight ratios were calculated. The brain, spleen, thymus, gross lesions and known target organs were preserved in neutral, phosphate-buffered 10% formalin. Dead or moribund pups were examined in a similar manner for possible defects and/or cause of death and were preserved in neutral, phosphate-buffered 10% formalin.

Statistics:

See below "Any other information on material and methods"

Reproductive indices:

Reproductive indices were calculated for all dose level groups as follows:
• Female mating index = (No. females with evidence of mating/No. paired) x 100
• Male mating index = (No. males with evidence of mating/No. paired) x 100
• Female conception index = (No. females with evidence of pregnancy/No. mated) x 100
• Male conception index = (No. males siring a litter/No. mated) x 100
• Female fertility index = (No. females with evidence of pregnancy/No. paired) x 100
• Male fertility index = (No. males siring a litter/No. paired) x 100
• Gestation index = (No. females delivering a viable litter/No. females with evidence of pregnancy) x 100
• Gestation survival index = percentage of delivered pups alive at birth
• Post-implantation loss = (No. implants – No. viable offspring)/(No. implants) x 100
• Day 1 or 4 pup survival index = (No. viable pups on day 1 or 4/No. born live) x 100
• Day 7, 14, 21 or 28 pup survival index = (No. viable pups on day 7, 14, 21 or 28/No. live after culling) x 100

Offspring viability indices:

• Day 1 or 4 pup survival index = (No. viable pups on day 1 or 4/No. born live) x 100
• Day 7, 14, 21 or 28 pup survival index = (No. viable pups on day 7, 14, 21 or 28/No. live after culling) x 100

Screening Test- Treatment-related clinical signs in the 150 ppm P1 males and females were limited to a transient sneezing/huffing sound noted each day immediately following the end of exposure, occurring from day 36. This sound was observed until termination of the P1 males. In females, this sound was no longer present when exposure was stopped from GD 21 – LD 4, but was observed again upon resumption of exposure (LD 5-28), albeit at a lesser severity and incidence. P1 males and females exposed to 150 ppm had treatment-related decreases in body weights, body weight gains and feed consumption that were observed during the pre-breeding, gestation and lactation phases. Similar, but less severe effects on body weight and feed consumption were seen in males and females exposed to 75 ppm. There was a dose-dependent decrease in the terminal body weights of rats exposed to methyl acrylate.

There were no treatment-related effects on any reproductive parameters, organ weights, or gross pathology. Dose-related histopathologic effects were present in the nasal tissues of males and females at all exposure concentrations. Degeneration with regeneration of the olfactory epithelium (very slight to severe) occurred in males and females at 150 ppm and in males at 75 ppm. Regenerative hyperplasia of the olfactory epithelium accompanied the degenerative change in multifocal sites. A lesser degree of olfactory epithelial degeneration (very slight), without accompanying regenerative hyperplasia, was noted in females at 75 ppm, and in males and females at 25 ppm. Very slight or slight degeneration of the olfactory nerve was present in males and females at 150 ppm only. Very slight or slight chronic active inflammation accompanied the olfactory epithelial degeneration in males and females at 150 ppm, and in females at 75 ppm. Very slight necrosis of individual olfactory epithelial cells, and multifocal, very slight or slight hyperlasia of the transitional epithelium that covers the nasal turbinates was present in rats exposed to 25, 75, or 150 ppm. There was a slight decrease in the PND 14 body weight of pups whose dams were exposed to 150 ppm methyl acrylate. No clinical signs were observed in the F1 males or females that were exposed from PND 28-35. F1 males and females exposed to 150 ppm had treatment-related decreases in body weights and feed consumption. Similar, but less severe effects on body weight and feed consumption were seen in F1 males and females exposed to 75 ppm.

Percent Difference in Terminal Body Weight Compared to Control
25 ppm 75 ppm 150 ppm
P1 Males -1% -7% -13%
P1 Females -1% -2% -12%
F1 Males +2% -4% -18%
F1 Females -1% -9% -17%

Chamber Concentration
Mean chamber concentration values during the study were 0, 5.3 ± 0.2, 25.7 ± 0.3, and 75.4 ± 0.6 ppm. Actual mean chamber concentration values deviated 0.5-6% from the targeted values of 0, 5, 25, and 75 ppm.

In-Life Observations
Examinations performed on all animals prior to the study start revealed that all animals were in good health for study purposes.

No treatment-related effects on behavior or demeanor were observed in any phase of the study at any dose level. A number of incidental observations bearing no relation to treatment were observed.

Feed Consumption
There was a treatment-related decrease in feed consumption of the P1 males in the 75 ppm exposure group when compared to controls, although these differences only reached statistical significance for three measurement intervals (TD 1-7, 7-14, and 56-63) throughout the first generation. During the 10-week premating period, there was a treatment-related decrease in feed consumption of the P1 females in the 75 ppm exposure group when compared to controls, and these differences reached statistical significance for most measurement intervals. Feed consumption of the 75 ppm females was also decreased throughout gestation (≤ 12%) when compared to controls. During lactation, feed consumption of the 75 ppm females was slightly decreased when compared to controls, although these differences only reached statistical significance for three measurement intervals (LD 14-17, 17-19, and 23-26). There were no treatment-related or statistical differences in feed consumption of P1 males and females exposed to 25 or 5 ppm methyl acrylate when compared to controls.

Selected P1 Male Feed Consumption Data
Mean g/Animal/Day
ppm: 0 5 25 75
TD 1-7 22.4 21.7 22.8 20.0*
TD 7-14 24.2 24.8 24.7 23.0*
TD 21-28 24.9 24.1 25.9 24.8
TD 42-49 26.8 26.1 26.1 25.7
TD 56-63 27.4 26.0 26.6 25.0*
TD 86-91 27.1 25.8 27.4 25.5
* Statistically different from control mean by Dunnett’s test, alpha = 0.05.

Selected P1 Female Feed Consumption Data
Mean g/Animal/Day
ppm: 0 5 25 75
Premating days 1-7 16.2 15.0 15.9 14.2$
Premating days 7-14 16.6 16.9 16.6 15.4*
Premating days 21-28 17.6 17.3 17.7 16.7
Premating days 42-49 18.8 18.0 17.8 17.3*
Premating days 56-63 18.0 17.2 17.2 13.3$
Premating days 63-70 18.1 17.4 17.3 18.8
GD 0-7 22.6 21.3 22.1 19.9*
GD 7-14 23.8 22.9 23.8 21.7*
GD 14-21 23.2 23.1 22.6 21.0*
LD 1-4 29.4 32.1 29.8 30.4
LD 7-11 40.6 41.8 41.2 38.1
LD 14-17 51.8 52.1 50.6 48.3$
LD 23-26 90.9 90.9 92.5 87.3$
* Statistically different from control mean by Dunnett’s test, alpha = 0.05.
$ Statistically different from control mean by Wilcoxon’s test, alpha = 0.05.

There was a treatment-related decrease in feed consumption of the P2 males in the 75 ppm exposure group when compared to controls, and these differences reached statistical significance for the majority of measurement intervals throughout the second generation. During the 10-week premating period, there was a treatment-related decrease in feed consumption of the P2 females in the 75 ppm exposure group when compared to controls, and these differences also reached statistical significance for most measurement intervals. Feed consumption of the 75 ppm females was also decreased throughout gestation (≤ 10%) when compared to controls. During lactation, feed consumption of the 75 ppm females was slightly decreased when compared to controls, although these differences only reached statistical significance for two measurement intervals (LD 7-11 and 14-17). There were no treatment-related differences in feed consumption of P2 males and females exposed to 25 or 5 ppm methyl acrylate when compared to controls. The difference in feed consumption of 5 ppm males when compared to controls was statistically identified and decreased for two measurement intervals (TD 1-6 and 34-41), however, this was not considered to be a treatment-related effect due to the lack of both a dose-response relationship and temporal association.

Selected P2 Male Feed Consumption Data
Mean g/Animal/Day
ppm: 0 5 25 75
TD 1-6 24.3 22.6* 24.7 20.8*
TD 6-13 27.0 25.6 27.2 23.8*
TD 20-27 28.7 27.6 29.4 26.2*
TD 34-41 29.4 27.6* 29.5 26.9*
TD 41-48 28.7 27.6 29.9 27.0
TD 55-62 29.3 28.0 29.7 27.1*
TD 90-97 29.0 28.5 29.2 26.6*
* Statistically different from control mean by Dunnett’s test, alpha = 0.05.

Selected P2 Female Feed Consumption Data
Mean g/Animal/Day
ppm: 0 5 25 75
Premating days 1-6 19.3 19.0 18.4 17.1$
Premating days 6-13 19.9 19.6 19.2 17.7*
Premating days 20-27 20.2 19.4 19.8 18.0*
Premating days 41-48 20.4 19.1 20.0 19.2
Premating days 55-62 18.6 19.1 18.9 18.8
Premating days 62-69 19.1 18.3 18.8 17.6*
GD 0-7 23.1 22.3 22.7 21.1*
GD 7-14 25.2 23.9 25.0 22.7*
GD 14-21 24.1 23.0 23.1 21.9*
LD 1-4 33.7 32.4 30.6 33.0
LD 7-11 46.0 44.7 43.7 41.9*
LD 14-17 55.3 53.7 53.0 51.1*
LD 23-26 95.0 93.2 92.5 91.9
* Statistically different from control mean by Dunnett’s test, alpha = 0.05.
$ Statistically different from control mean by Wilcoxon’s test, alpha = 0.05.


Body Weights/Body Weight Gains
There was a treatment-related decrease in the body weight of P1 males of the 75 ppm exposure group when compared to controls, although these differences only reached statistical significance on TD 7 and 14 throughout the entire first generation. Similarly, there was a treatment-related decrease in the body weight of P1 females of the 75 ppm exposure group, which reached statistical significance on three days (TD 21, 63, and 70) of the 10-week premating period. There was a treatment-related decrease in the body weight of P1 females of the 75 ppm exposure group across the entire
gestation and lactation period. However, gestation body weight gain of the 75 ppm females remained comparable to controls. During lactation, the 75 ppm females did not lose as much body weight as controls, which could have been related to their lower body weight at the start of lactation. There were no treatment-related differences in body weight of P1 males and body weight/body weight gain of P1 females exposed to 25 or 5 ppm methyl acrylate when compared to controls. The difference in body weight of 5 ppm males (TD 7) and gestation body weight gain of 5 ppm females (GD 0-7) was statistically identified and decreased when compared to their respective controls. However, this was not considered to be a treatmentrelated effect due to the lack of a dose-response relationship and the low incidence.

Selected P1 Male Body Weights
Mean Body Weight (g)
ppm 0 5 25 75
TD 1 193.9 190.4 193.6 191.9
TD 7 237.8 228.0* 235.9 226.3*
TD 14 291.1 286.8 284.9 276.7*
TD 28 369.3 358.5 366.7 358.6
TD 70 512.4 492.5 499.2 487.3
* Statistically different from control mean by Dunnett’s test, alpha = 0.05.

Selected P1 Female Pre-Breeding Body Weights
Mean Body Weight (g)
ppm 0 5 25 75
TD 1 139.4 136.4 138.9 139.8
TD 7 158.7 153.8 159.0 152.5
TD 21 203.8 203.0 204.6 191.5*
TD 63 273.1 266.1 272.4 248.1*
TD 70 281.7 272.0 276.6 258.5*
* Statistically different from control mean by Dunnett’s test, alpha = 0.05

Selected P1 Gestation/Lactation Body Weights/Body Weight Gains
Gestation Mean Body Weight (g)
ppm 0 5 25 75
GD 0 287.4 280.1 284.3 261.8*
GD 7 319.3 302.7 315.8 289.0*
GD 14 350.1 337.2 347.5 318.5*
GD 21 433.8 429.4 435.9 404.6*

Gestation Mean Body Weight Gains (g)
GD 0-21 146.4 149.3 151.6 142.9
Lactation Mean Body Weight (g)
LD 1 330.9 316.4 321.6 297.7*
LD 4 343.8 335.6 337.2 312.6*
LD 7 328.0 323.0 324.4 297.9*
LD 14 336.9 334.8 335.6 308.8*
LD 28 313.4 306.6 309.3 294.6*
Lactation Mean Body Weight Gains (g)
LD 1-28 -17.5 -9.8 -12.3 -3.1*
* Statistically different from control mean by Dunnett’s test, alpha = 0.05.

There was a treatment-related decrease in the body weight of P2 males of the 75 ppm exposure group when compared to controls, which was statistically identified throughout the entire second generation. Similarly, there was a treatment-related decrease in the body weight of P2 females of the 75 ppm exposure group, which reached statistical significance on all measurement days during the 10-week premating period. There was a treatment-related decrease in the body weight of P2 females of the 75 ppm exposure group across the entire gestation and lactation periods. The gestation body weight gains of the 75 ppm females were significantly lower than control values, however, this difference was equivocal when all dose groups were considered. As in the P1 females, the net body weight loss typical of lactating female rats was less in the 75 ppm females than it was in controls. There were no treatment-related differences in body weight of P2 males and body weight/body weight gain of P2 females exposed to 25 or 5 ppm methyl acrylate when compared to controls. Statistical differences in the body weight/body weight gain of 25 or 5 ppm females were not considered to be treatment-related due to the lack of a doseresponse relationship and/or the low incidence.

Selected P2 Male Body Weights
Mean Body Weight (g)
ppm 0 5 25 75
TD 1 169.7 158.0 170.9 148.4*
TD 6 212.6 200.7 213.6 181.2*
TD 13 274.6 258.9 277.9 239.6*
TD 27 373.7 365.2 379.0 330.4*
TD 69 538.4 512.4 540.3 472.3*
* Statistically different from control mean by Dunnett’s test, alpha = 0.05.

Selected P2 Female Pre-Breeding Body Weights
Mean Body Weight (g)
ppm 0 5 25 75
TD 1 143.6 135.6 135.6 125.1*
TD 6 166.4 160.0 156.4 144.3*
TD 13 194.3 187.0 183.1 169.9*
TD 27 238.9 229.4 228.3 206.4*
TD 69 299.5 288.1 293.2 264.1*
* Statistically different from control mean by Dunnett’s test, alpha = 0.05
Selected P2 Gestation/Lactation Body Weights/Body Weight Gains
Gestation Mean Body Weight (g)
ppm 0 5 25 75
GD 0 298.7 292.5 290.2 266.5*
GD 7 334.0 319.7 321.7 294.7*
GD 14 367.1 350.4 353.3 324.4*
GD 21 459.3 437.6 440.5 412.4*
Gestation Mean Body Weight Gains (g)
GD 0-21 160.6 145.1* 150.3 145.9*
Lactation Mean Body Weight (g)
LD 1 345.1 328.3 337.0 303.8*
LD 4 365.4 345.6* 350.4 323.0*
LD 7 352.6 333.7 336.4 311.2*
LD 14 358.3 338.3* 341.1 321.2*
LD 28 322.5 310.0 314.4 298.0*
Lactation Mean Body Weight Gains (g)
LD 1-28 -22.6 -18.2 -22.5 -6.1*
* Statistically different from control mean by Dunnett’s test, alpha = 0.05.

Organ Weights
P1 males and females exposed to 75 ppm had treatment-related lower final body weights (statistically identified in females at 75 ppm). The final body
weights of P1 males and females exposed to 75 ppm were 5.0% and 7.7% lower than controls, respectively. The relative weights of the testes and epididymides of males exposed to 75 ppm, and the relative weights of the liver and brain of females exposed to 75 ppm were statistically identified as higher than controls. The elevated relative organ weights of males and females exposed to 75 ppm were interpreted to be reflective of the lower body weights of these animals as the absolute weights of the organs were not different from the controls. The relative testes weight of males exposed to 5 ppm, and the relative liver weight of females exposed to 5 ppm were statistically identified as higher than controls. These organ weight alterations were interpreted to be unrelated to treatment due to the lack of a dose response. The absolute pituitary weights of males exposed to 5 or 25 ppm, and females exposed to 5, 25, or 75 ppm were statistically identified as lower than controls. In addition, the relative pituitary weight of males exposed to 25 ppm was statistically identified as lower than controls. The alterations in pituitary weights were interpreted to be unrelated to treatment because of the a lack of a clear dose response, the absence of any histopathologic correlates in males and females from the high-dose group, and because all of the pituitary weights were within historical controls ranges of studies recently conducted at this laboratory.

Organ Weight Data – P1 Adults
Concentration (ppm)
0 Historical1 5 25 75
Parameter MALES
Final Body Weight (g) 554.0 520.1-581.8 540.9 549.8 526.1a
Relative Testes (g/100g bw) 0.635 0.608-0.695 0.698* 0.673 0.709*
Relative Epididymides (g/100g bw) 0.248 0.238-0.277 0.264 0.261 0.277*
Absolute Pituitary (g) 0.0146 0.011-0.015 0.0133* 0.0130* 0.0138
Relative Pituitary (g/100g bw) 0.0026 0.002-0.002 0.0025 0.0024* 0.0026
Parameter FEMALES
Final Body Weight (g) 314.2 278.0-330.4 300.8 311.5 290.1*a
Relative Liver (g/100g bw) 2.878 2.994-3.491 3.103* 3.008 3.105*
Relative Brain (g/100g bw) 0.658 0.651-0.692 0.685 0.658 0.699$
Absolute Pituitary (g) 0.0200 0.012-0.018 0.0175* 0.0179* 0.0171*
*Statistically different from control mean by Dunnett’s Test, alpha = 0.05.
$Statistically different from control mean by Wilcoxon’s Test, alpha =0.05.
1Historical controls group mean range from seven dietary studies reported between 2002 and 2006.
a- Values interpreted to be treatment-related effects.

P2 males and females exposed to 75 ppm had statistically identified treatment-related lower final body weights. The final body weights of P2 males and females exposed to 75 ppm were 13.1% and 9.6% lower than controls, respectively. The relative weights of the brain, testes, seminal vesicles (with coagulating glands) and epididymides of males exposed to 75 ppm, and the relative weights of the adrenals and brain of females exposed to 75 ppm were statistically identified as higher than controls. The absolute weights of the adrenals, kidneys, spleen, pituitary gland, and thyroid gland of males exposed to 75 ppm, and the absolute weights of the kidneys, spleen and thyroid gland of females exposed to 75 ppm were statistically identified as lower than controls. The organ weight alterations of males and females exposed to 75 ppm were interpreted to be reflective of the lower body weights of these animals. Males exposed to 25 ppm had statistically identified lower absolute and relative pituitary weights, and females exposed to 25 ppm had a statistically identified lower absolute thyroid weight. Males exposed to 5 ppm had a statistically identified higher relative testes weight, and females exposed to 5 ppm had statistically identified higher absolute and relative adrenal weights. The organ weight alterations from the 5 and 25 ppm dose groups were interpreted to be unrelated to treatment due to the lack of a clear dose response and/or the values were within historical controls
ranges of studies recently conducted at this laboratory.

Organ Weight Data – P2 Adults
Concentration (ppm)
0 Historical1 5 25 75
Parameter MALES
Final Body Weight (g) 624.4 606.9-674.8 599.9 627.6 542.9*a
Absolute Adrenal Glands (g) 0.055 0.062-0.073 0.054 0.056 0.048*
Absolute Kidneys (g) 4.058 3.924-4.350 4.010 4.002 3.671*
Relative Brain (g/100g bw 0.346 0.333-0.386 0.363 0.344 0.386*
Absolute Spleen (g) 0.895 0.845-0.963 0.905 0.867 0.783*
Relative Testes (g/100g bw) 0.582 0.571-0.641 0.636* 0.593 0.662*
Relative Seminal Vesicle (g/100g bw) 0.319 0.266-0.319 0.322 0.312 0.367*
Relative Epididymides (g/100g bw) 0.223 0.224-0.248 0.238 0.229 0.255*
Absolute Pituitary (g) 0.0149 0.009-0.017 0.0141 0.0137* 0.0134*
Relative Pituitary (g/100g bw) 0.0024 0.002-0.003 0.0024 0.0022* 0.0025
Absolute Thyroid Gland (g) 0.0253 0.0224-0.0284 0.0255 0.0269 0.0224*
Parameter FEMALES
Final Body Weight (g) 326.3 296.3-347.2 313.7 318.4 295.0*a
Absolute Adrenal Glands (g) 0.062 0.070-0.111 0.068* 0.064 0.067
Relative Adrenal Glands (g/100g bw) 0.019 0.023-0.035 0.022* 0.020 0.023*
Absolute Kidneys (g) 2.274 2.187-2.424 2.259 2.149 2.108*
Relative Brain (g/100g bw) 0.620 0.588-0.703 0.644 0.628 0.669*
Absolute Spleen (g) 0.585 0.593-0.620 0.543 0.562 0.513*
Absolute Thyroid Gland (g) 0.0203 0.0166-0.0202 0.0182 0.0180* 0.0180*
*Statistically different from control mean by Dunnett’s Test, alpha = 0.05.
1Historical controls group mean range from seven dietary studies reported between 2002 and 2006.
a-Values interpreted to be treatment-related effects.
Gross Pathology
There were no treatment-related gross pathologic observations. All gross pathologic observations were considered to be incidental findings, unassociated with exposure to methyl acrylate.

Histopathology
Treatment-related histopathologic effects were present in the nasal tissues of P1 and P2 males and females given 25 or 75 ppm. The incidence and severity of the nasal effects were dose-related. Degeneration with regeneration of the olfactory epithelium (very slight to moderate) occurred in all P1 and P2 males and females exposed to 75 ppm. The degeneration consisted of thinning and disarray of the olfactory epithelial cells, which was most prevalent in the anterior and dorsal aspects of the nasal passages. Regenerative hyperplasia of the olfactory epithelium accompanied the degenerative change in multifocal sites. A lesser degree of multifocal olfactory epithelial degeneration (very slight), without accompanying regenerative hyperplasia, was noted in 7/27 P1 females exposed to 25 ppm, and in 6/27 P2 males and 8/27 P2 females exposed to 25 ppm. One P1 female and one P2 female exposed to 5 ppm also had very slight multifocal olfactory epithelial degeneration. However, the degeneration was located in only two sites of the nose for both of these animals, and therefore was interpreted to be comparable with spontaneous focal olfactory epithelial degeneration that was noted in 2/27 control group P1 females and 3/27 control group P2 females, and not an effect of treatment.

There were several histopathologic effects that accompanied the degeneration of the olfactory epithelium. Very slight or slight degeneration of the olfactory nerve was present in most of the P1 and P2 males and females exposed to 75 ppm, and one P1 male exposed to 25 ppm. This effect was characterized by thinning of the axons and reduction in the diameter of the olfactory nerve fascicles in areas of olfactory epithelial degeneration. Very slight or slight multifocal chronic-active inflammation accompanied the olfactory epithelial degeneration in 16/27 P1 males, 20/27 P1 females, 14/27 P2 males, and 8/27 P2 females exposed to 75 ppm, and in one or two males and females from both generations exposed to 25 ppm. The inflammation
consisted of neutrophils in the olfactory epithelium, with or without the presence of a mucopurulent exudate. Very slight multifocal necrosis of individual olfactory epithelial cells, with or without exfoliation of necrotic cells into the lumen of the nasal passages, was present in most of the P1 and P2 males and females exposed to 75 ppm, and a few P1 and P2 animals (one to four per sex) exposed to 25 ppm. One P1 female exposed to 5 ppm also had very slight multifocal necrosis of individual olfactory epithelial cells. However, the necrosis was located in only two sites of the nose in this animal, and therefore was interpreted to be comparable with spontaneous focal olfactory epithelial cell necrosis that was noted in one control group P1 male, one control group P1 female, and one control group P2 female, and not an effect of treatment.

A treatment-related increase in the incidence of very slight or slight multifocal hyperplasia of the transitional epithelium that covers the nasal turbinates was present in P1 and P2 males and females exposed to 25 or 75 ppm. The incidence and severity of transitional epithelial hyperplasia in P1 and P2 males and females exposed to 5 ppm was comparable to controls.

A treatment-related increase in the incidence of very slight or slight diffuse hyperplasia and hypertrophy of the respiratory epithelium that covers the nasal septum and dorsal portion of the anterior nasal cavity was present in P1 males and females exposed to 25 or 75 ppm, and in P2 males and females exposed to 75 ppm. The incidence and severity of respiratory epithelial hyperplasia and hypertrophy in P1 and P2 males and females exposed to 5 ppm was comparable to controls.

Treatment-related very slight focal or multifocal mineralization of the olfactory epithelium was present in one or two P1 and P2 animals exposed to 25 ppm, 6/27 P1 males, 4/27 P1 females, 16/27 P2 males and 14/27 P2 females exposed to 75 ppm. The mineralization was present in areas olfactory epithelial degeneration. One P1 female exposed to 75 ppm also had slight multifocal mineralization of the nasal respiratory epithelium that was interpreted to be treatment related. Other treatmentrelated nasal effects consisted of very slight multifocal squamous metaplasia of the transitional epithelium in 5/27 P1 males exposed to 75 ppm, and ulceration of the olfactory epithelium in four P1 males, one P1 female, and one P2 female exposed to
75 ppm.

All other histopathologic observations were considered to be spontaneous alterations, or caused by accidental trauma, unassociated with inhalation exposure of methyl acrylate. There were no histopathologic systemic effects in P1 or P2 rats at any exposure level. The NOEC for histopathologic nasal effects was 5 ppm.

Histopathologic Nasal Tissue Effects – P1 Males
Dose (ppm) 0 5 25 75
NASAL TISSUE - PHARYNX (number examined) (27) (27) (27) (27)
Degeneration, olfactory nerve, multifocal -very slight 0 0 1a 11a
-slight 0 0 0 14a
Degeneration with Regeneration, olfactory epithelium, multifocal
-slight 0 0 1a 12a
-moderate 0 0 0 15a
Hyperplasia, transitional epithelium; multifocal -very slight 3 4 17a 12a
-slight 0 0 0 15a
Hyperplasia and Hypertrophy, goblet cell, respiratory epithelium, diffuse
-very slight 1 0 4a 1
-slight 0 0 1a 22a
Inflammation, chronic active, olfactory epithelium, multifocal
-very slight 1 0 2 15a
-slight 0 0 0 1a
Metaplasia, squamous, transitional epithelium, multifocal -very slight 0 0 0 5a
Mineralization, olfactory epithelium, focal -very slight 0 0 0 1a
Mineralization, olfactory epithelium, multifocal -very slight 0 0 1a 5a
Necrosis, individual cell, olfactory epithelium, focal -very slight 1 0 1 0
Necrosis, individual cell, olfactory epithelium, multifocal -very slight 0 0 1a 26a
Ulcer, olfactory epithelium, focal -very slight 0 0 0 4a
a- Indicates the effects judged to be treatment-related.

Results Continued in Remarks Section (below)

Dose descriptor:

NOEC

Remarks:

maternal toxicity

Effect level:

ca. 0.092 mg/L air (analytical)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: corresponding to 25 ppm; based on decreases in pup weight at 75 ppm which were secondary to parental toxicity.

Remarks on result:

other: Generation: P1, P2 (migrated information)

Dose descriptor:

NOEC

Remarks:

reproductive toxicity

Effect level:

ca. 0.269 mg/L air (analytical)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: corresponding to 75 ppm; the highest concentration tested.

Remarks on result:

other: Generation: P1 and P2 (migrated information)

Dose descriptor:

NOEC

Remarks:

developmental toxicity

Effect level:

ca. 0.092 mg/L air (analytical)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: based on decreased body weight of the pups

Remarks on result:

other: Generation: P3 (migrated information)

Dose descriptor:

NOEC

Remarks:

maternal local toxicity

Effect level:

ca. 0.019 mg/L air (analytical)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: corresponding to 5 ppm; based on histologic changes in nasal tissues.

Remarks on result:

other: Generation: P1 and P2 (migrated information)

In-Life Observations

No treatment-related effects on behavior or demeanor were observed in any phase of the study at any dose level. A number of incidental observations bearing no relation to treatment were observed.

Observations made on F1 and F2 pups during their respective lactation periods revealed no effects related to treatment. Incidental findings, which included a small number of observations in the control, low-, middle-, and high-dose groups, were seen with no evidence of a dose-response relationship. Included among these incidental findings was a single high dose pup which exhibited a head tilt and circling behavior associated with overgrown incisors. This pup was euthanized on lactation day 25.

Reproductive Indices, Pup Survival and Sex Ratio
There were no effects of treatment at any exposure level on mating, conception, fertility or gestation indices, post-implantation loss, time to mating, gestation length, pup survival or pup sex ratio in either generation.

Litter Size
There were no effects of treatment on the number of pups born live, number of pups born dead, or on litter size at any time interval in any exposure group for either generation.

Pup Body Weight
F1 pup body weights from all exposure groups were comparable to control until PND 14. Male and female pups from the 75 ppm exposure group had decreased body weights that were statistically identified when compared to control on PNDs 14, 21, and 28. There were no treatment-related findings for F1 pup body weights from the 25 or 5 ppm exposure groups when compared to control. On PND 7, there was a statistically identified decrease in pup body weights of F1 females from the 5 ppm exposure group. This was considered spurious and unrelated to treatment due to the lack of a dose response relationship and because it was not repeated in the next generation.

Treatment-related effects on the body weights of F2 pups were similar to what was seen in the previous generation. F2 pup body weights from all exposure groups were comparable to control until PND 14. Male and female pups from the 75 ppm exposure group had decreased body weights that were statistically identified when compared to control on PNDs 14, 21, and 28. There were no treatment-related or statistical findings for F1 pup body weights from the 25 or 5 ppm exposure groups when compared to control.

These findings are likely secondary to maternal toxicity in the form of decreased maternal body weights of ~10% and severe nasal irritation. This conclusion is supported by a feed restriction study where a 10-20% decrease in maternal body weight can lead to decreased pup weights by as much as 21% (Carney, et al., 2004).

Selected F1 Pup Body Weights (g)
0 ppm 5 ppm 25 ppm 75 ppm
PND 14 Males 27.0 26.7 26.3 24.3*
Percent from Control NA -1% -3% -10%
PND 14 Females 26.5 25.8 25.6 23.7*
Percent from Control NA -3% -3% -11%
PND 21 Males 44.2 42.3 42.6 39.5*
Percent from Control NA -4% -4% -11%
PND 21 Females 43.8 41.1 41.4 39.3*
Percent from Control NA -6% -6% -10%
PND 28 Males 83.1 82.2 82.0 77.3*
Percent from Control NA -1% -1% -7%
PND 28 Females 79.4 76.6 76.6 73.1*
Percent from Control NA -4% -4% -8%
*Statistically different from control mean by Dunnett’s Test, alpha = 0.05.

Selected F2 Pup Body Weights (g)
0 ppm 5 ppm 25 ppm 75 ppm
PND 14 Males 30.3 29.8 29.6 27.4*
Percent from Control NA -2% -2% -10%
PND 14 Females 29.7 28.7 29.0 26.7*
Percent from Control NA -3% -2% -10%
PND 21 Males 49.0 48.7 47.5 44.1*
Percent from Control NA -1% -3% -10%
PND 21 Females 48.3 46.5 46.8 42.9*
Percent from Control NA -4% -3% -11%
PND 28 Males 89.7 89.7 87.5 83.4*
Percent from Control NA 0% -2% -7%
PND 28 Females 84.2 82.3 82.0 77.8*
Percent from Control NA -2% -3% -8%
*Statistically different from control mean by Dunnett’s Test, alpha = 0.05.

Puberty Onset
Age at vaginal opening and age at preputial separation were similar in all exposure groups, indicating no effect of treatment on these end points despite the lower body weight of the 75 ppm animals.

Organ Weights
The final body weights of F1 weanling males and females from the 75 ppm group were approximately 6% lower than controls, and although not statistically identified, were considered treatment-related due to the immediately preceding decrease in pup body weights from PND 14-28. There were no
treatment-related alterations in organ weights of F1 weanlings at any dose level.

Final Body Weight Data – F1 Weanlings
Concentration (ppm)
0 5 25 75
Parameter MALES
Final Body Weight (g) 88.1 86.7 87.2 82.6a
Parameter FEMALES
Final Body Weight (g) 81.9 77.8 80.6 76.7a
a- Values interpreted to be treatment-related effects.

F2 weanling males and females from the 75 ppm group had treatment-related lower final body weights (statistically identified in females at 75 ppm). The final body weights of F2 weanling males and females from the 75 ppm group were 5.8% and 7.7% lower than controls, respectively. As in the 75 ppm group F1 pups, these decreases in final body weights (PND 29) were reflective of the statistically significant decreases in pup body weights during the preceding two weeks. There were no treatment-related alterations in organ weights of F2 weanlings at any dose level. The only statistically identified organ weight alteration was a higher absolute brain weight in F2 male weanlings from the 5 ppm exposure group, which was unrelated to treatment due to the lack of a dose response.

Final Body Weight Data – F2 Weanlings
Concentration (ppm)
0 5 25 75
Parameter MALES
Final Body Weight (g) 94.6 93.0 94.6 89.1a
Parameter FEMALES
Final Body Weight (g) 87.2 84.7 84.5 80.4*a
*Statistically different from control mean by Dunnett’s Test, alpha = 0.05.
a- Values interpreted to be treatment-related effects.

Gross Pathology
There were no treatment-related gross pathologic observations in F1 weanlings at any exposure level. In F2 weanlings, 2/81 males and 3/78 females from the 75 ppm exposure group had necrosis of the tail. This observation may have been related to treatment, but the significance of the tail necrosis is not known. All other gross pathologic observations from F1 and F2 weanlings were considered to be spontaneous alterations, unassociated with exposure to methyl acrylate.

Reproductive effects observed:

not specified

Results- Continued

Histopathologic Nasal Tissue Effects

P1 Females

Dose (ppm) 0 5 25 75

NASAL TISSUE - PHARYNX (number examined) (27) (27) (27) (27)

Degeneration, olfactory epithelium, focal -very slight 2 1 4 0

Degeneration, olfactory epithelium, multifocal -very slight 0 1 7a 0

Degeneration, olfactory nerve, multifocal -very slight 0 0 0 8a

-slight 0 0 0 19a

Degeneration with Regeneration, olfactory epithelium, multifocal-slight 0 0 0 8a

-moderate 0 0 0 19a

Hyperplasia, transitional epithelium; multifocal -very slight 2 1 23a 24a

-slight 0 0 2a 3a

Hyperplasia and Hypertrophy, goblet cell, respiratory epithelium, diffuse-very slight 0 1 8a 10a

-slight 0 0 13a 1a

Inflammation, chronic active, olfactory epithelium, multifocal-very slight 0 0 1 20a

Inflammation, chronic active, respiratory epithelium, multifocal-very slight 0 0 1 5a

Mineralization, olfactory epithelium, focal -very slight 0 0 0 2a

Mineralization, olfactory epithelium, multifocal -very slight 0 0 0 2a

Mineralization, respiratory epithelium, focal -slight 0 0 0 1a

Necrosis, individual cell, olfactory epithelium, focal -very slight 1 0 3 0

Necrosis, individual cell, olfactory epithelium, multifocal -very slight 0 1 2a 26a

Ulcer, olfactory epithelium, focal -very slight 0 0 0 1a

a-Indicates the effects judged to be treatment-related.  

Histopathologic Nasal Tissue Effects

P2 Males Dose (ppm) 0 5 25 75

NASAL TISSUE - PHARYNX (number examined) (27) (27) (27) (27)

Degeneration, olfactory epithelium, focal -very slight 0 0 1 0

Degeneration, olfactory epithelium, multifocal, -very slight 0 0 6a 0

Degeneration, olfactory nerve, multifocal -very slight 0 0 0 14a

-slight 0 0 0 13a

Degeneration with Regeneration, olfactory epithelium, multifocal-slight 0 0 0 13a

-moderate 0 0 0 14a

Hyperplasia, transitional epithelium; multifocal -very slight 4 4 18a 8a

-slight 0 0 2a 19a

Hyperplasia and Hypertrophy, goblet cell, respiratory epithelium, diffuse-very slight 0 0 0 6a

-slight 0 0 0 3a

Inflammation, chronic active, olfactory epithelium, multifocal-very slight 0 0 0 14a

Mineralization, olfactory epithelium, focal -very slight 0 0 1a 1a

Mineralization, olfactory epithelium, multifocal -very slight 0 0 1a 15a

Necrosis, individual cell, olfactory epithelium, multifocal -very slight 0 0 1a 24a

Ulcer, olfactory epithelium, focal -very slight 1 0 0 1a a-Indicates the effects judged to be treatment-related.

Histopathologic Nasal Tissue Effects

P2 Females Dose (ppm) 0 5 25 75

NASAL TISSUE - PHARYNX (number examined) (27) (27) (27) (27)

Degeneration, olfactory epithelium, focal -very slight 3 2 4 0

Degeneration, olfactory epithelium, multifocal -very slight 0 1 8a 0

Degeneration, olfactory nerve, multifocal -very slight 0 0 0 14a

-slight 0 0 0 12a

Degeneration with Regeneration, olfactory epithelium, multifocal-very slight 0 0 0 1a

-slight 0 0 0 14a

-moderate 0 0 0 12a

Hyperplasia, transitional epithelium; multifocal -very slight 9 6 23a 25a

-slight 1 0 0 1a

Hyperplasia and Hypertrophy, goblet cell, respiratory epithelium, diffuse-very slight 7 8 11 16a

-slight 3 1 5 2

Inflammation, chronic active, olfactory epithelium, multifocal-very slight 0 0 1a 8a

Mineralization, olfactory epithelium, multifocal -very slight 0 0 1a 14a

Necrosis, individual cell, olfactory epithelium, focal -very slight 1 0 1 0

Necrosis, individual cell, olfactory epithelium, multifocal -very slight 0 0 4a 27a

a-Indicates the effects judged to be treatment-related.

One P1 male exposed to 75 ppm (animal number 08A1350) died on test day 70. The cause of death was not determined. One P1 male exposed to 75 ppm (animal umber 08A1351) was euthanized moribund on test day 106. The cause of moribundity was urolithiasis, with associated inflammation and transitional cell hyperplasia of the urinary bladder and kidneys. One P1 male from the control group (animal number 08A1269) was euthanized moribund on test day 98. The cause of moribundity was lymphoid cell leukemia. Another P1 male from the control (animal number 08A1250) was euthanized on test day 113 due to accidental fracture of the upper jaw. One P2 female exposed to 25 ppm (animal number 08A5190) was euthanized on test day 57 due to severe inflammation of the hind feet. One P2 male exposed to 5 ppm (animal number 08A5040) was euthanized moribund on test day 87. The cause of moribundity was severe inflammation of the periodontal tissue associated with fracture of the upper incisors. One P2 female from the control group (animal number 08A5134) was euthanized on test day 70 due to accidental fracture of the nose. Histologic examination of the reproductive organs of animals with signs of reduced fertility did not reveal any effects of treatment. There were no treatment-related or statistically-identified differences in the mean number of small and growing ovarian follicles in females exposed to 75 ppm as compared to females from the control group.  

Sperm Parameters

There were no treatment-related effects of methyl acrylate on any sperm analysis parameter at any exposure level in either generation. There was a statistically identified increase in epididymal and testicular sperm counts of P1 males of the 75 ppm exposure group when compared to controls, which was due to two males in the control group (1258 and 1263) with very low sperm counts.  

Estrous Cyclicity

There was no evidence of an effect on estrous cyclicity at any dose level of methyl acrylate in either generation.

Effect on fertility: via oral route

Endpoint conclusion:

no study available

Effect on fertility: via inhalation route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

269 mg/m³

Study duration:

subchronic

Species:

rat

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

No reproductive toxicity studies are available for 2-propylheptyl acrylate. From the structurally analogous substance methyl acrylate (CAS No. 96-33-3) a 2-generation-study is available.

In a two-generation study according to OECD TG 416 groups of 27 male and female Crl:CD(SD) rats were whole-body exposed to the structural analogue methyl acrylate vapours at target concentrations of 0, 5, 25, and 75 ppm for six hours/day, seven days/week, resulting in actual average concentrations of 0, 5.3 ± 0.2, 25.7 ± 0.3, and 75.4 ± 0.6 ppm, respectively (corresponding to approx. 0, 0.019, 0.092, and 0.269 mg/L).Rats were exposed daily for approximately ten weeks prior to breeding, and continuing through breeding, gestation and lactation for two generations. Maternal rats were not exposed after GD 20 through LD 4 in order to allow for parturition and initiation of lactation. Exposure of maternal rats continued from LD 5 – LD 28. In-life parameters included clinical observations, feed consumption, body weights, estrous cyclicity, reproductive performance, pup survival, pup body weights, and puberty onset.In addition, post-mortem evaluations included gross pathology, histopathology, organ weights, oocyte quantitation and sperm count, motility and morphology in adults, and gross pathology and organ weights in weanlings. Treatment-related effects in parental rats exposed to 75 ppm included decreased body weight and feed consumption in males and females throughout most of the two generation study. There were no effects on body weight or feed consumption at 25 or 5 ppm. Treatment-related, adverse histopathologic effects were present in the nasal tissues of P1 and P2 males and females exposed to 25 or 75 ppm. The incidence and severity of the nasal effects were concentration dependent. Degeneration with regeneration of the olfactory epithelium (very slight to moderate) occurred in all P1 and P2 males and females exposed to 75 ppm. Very slight olfactory epithelial degeneration, without accompanying regenerative hyperplasia, was noted in some of the P1 and P2 females and P2 males exposed to 25 ppm. There were several histopathologic effects that accompanied the degeneration of the olfactory epithelium. Very slight or slight degeneration of the olfactory nerve was present in most of the P1 and P2 males and females exposed to 75 ppm, and one P1 male exposed to 25 ppm. Very slight or slight chronic-active inflammation was present in 16/27 P1 males, 20/27 P1 females, 14/27 P2 males, and 8/27 P2 females exposed to 75 ppm, and in one or two males and females from both generations exposed to 25 ppm. Very slight necrosis of individual olfactory epithelial cells was present in most of the P1 and P2 males and females exposed to 75 ppm, and a few P1 and P2 animals (one to four per sex) exposed to 25 ppm. Very slight mineralization of the olfactory epithelium was present in one or two P1 and P2 animals exposed to 25 ppm, and in 6/27 P1 males, 4/27 P1 females, 16/27 P2 males and 14/27 P2 females exposed to 75 ppm. Other nasal effects consisted of an increase in the incidence of very slight or slight hyperplasia of the transitional epithelium in P1 and P2 males and females exposed to 25 or 75 ppm, and an increase in the incidence of very slight or slight hyperplasia and hypertrophy of the respiratory epithelium in P1 males and females exposed to 25 or 75 ppm, and in P2 males and females exposed to 75 ppm. There were no treatment-related histopathologic effects in P1 or P2 animals exposed to 5 ppm.

No treatment-related effects were seen in reproductive function or pup survival. However, pup body weights of the 75 ppm exposure group were decreased on postnatal day 14-28 in both generations. There were no effects on pup body weight in rats exposed to 25 or 5 ppm. The effects on pup body weight, as well as the changes in parental body weight and feed consumption, likely were secondary changes all stemming from nasal irritation and resultant stress.

In summary, the no-observed-effect concentration (NOAEC) for parental systemic toxicity was determined to be 5 ppm (= ca. 0.019 mg/L) and was based on histologic changes in the nasal tissues seen at higher concentrations.The NOAEC for developmental toxicity was 25 ppm (= ca. 0.092 mg/L), based on decreases in pup body weight at 75 ppm which were secondary to parental toxicity. The NOAEC for reproductive toxicity was 75 ppm (= ca. 0.269 mg/L), the highest concentration tested.  

Short description of key information:
No reproductive toxicity studies are available for 2-propylheptyl acrylate. From the structurally analogous substance methyl acrylate (CAS No. 96-33-3) a 2-generation-study is available, in which groups of rats were whole-body exposed to methyl acrylate vapours, no effects on reproductive function (i.e. fertility) were observed. The NOAEC for reproductive function was 75 ppm (= ca. 0.269 mg/L).

Justification for selection of Effect on fertility via inhalation route:
GLP and guideline compliant study.

Effects on developmental toxicity

Description of key information

No developmental toxicity studies are available for 2-propylheptyl acrylate. From the structurally analogous substances 2-Ethylhexyl acrylate (CAS No. 103-11-7) and methyl acrylate (CAS No. 96-33-3) developmental toxicity studies are available in rats and rabbits. No indications of a developmental toxic / teratogenic effect were seen in animal studies with 2-ethylhexyl acrylate and its structural analogue methyl acrylate.

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2008-05-21 to 2009-04-07

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP and guideline study. Read across was performed with methyl acrylate. Please refer to IUCLID section 13 for read across justification.

Qualifier:

according to guideline

Guideline:

other: OECD Guideline for Testing of Chemicals; Proposal for updating Guideline 414: Prenatal Developmental Toxicity Study (22 Jan 2001)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rabbit

Strain:

Himalayan

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services, Germany GmbH
- Age at study initiation: 16-24 weeks
- Weight at study initiation (pregnant animals): 2202-2829 g
- Housing: Singly in type 12.2395.C stainless steel wire mesh cages. During exposure, the animals were kept singly in special mesh cages (40x13x16cm) from BASF SE.
- Diet: Pelleted “Kliba maintenance diet for rabbit & guinea pig, GLP” (Provimi Kliba SA, Kaiseraugst, Switzerland) ad libitum. During exposure, no food was supplied.
- Water: Tap water ad libitum. During exposure, no drinking water was supplied.
- Acclimation period: approx. 7-14 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 30-70
- Air changes (per hr): 15 times
- Photoperiod (hrs dark / hrs light): 12 / 12

Route of administration:

inhalation: vapour

Type of inhalation exposure (if applicable):

whole body

Vehicle:

other: conditioned supply air

Details on exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: glass steel inhalation chamber, volume of 1.4 m³ (BASF SE)
- Method of holding animals in test chamber: animals were kept singly in wire cages located in the inhalation chamber
- System of generating inhalation atmospheres: Generator systems: two-component atomizers (BASF SE); continuous infusion pumps PERFUSOR (B. Braun); Glass mixing stages (BASF SE); glass vaporizers with thermostat (BASF SE). Generation procedure: The test substance was used unchanged. For each concentration, the test substance was supplied to the two-component atomizer of a thermostated vaporizer at a constant rate by means of the piston metering pump. The vapor was generated by spraying the substance with compressed air into a counter current of conditioned supply air (about 50% ± 20% relative humidity, 22°C ± 2°C). Thereafter it was further mixed with conditioned supply air and passed into the inhalation system.


TEST ATMOSPHERE
- Brief description of analytical method used: GC analysis of absorption samples
- Samples taken from breathing zone: yes, immediately adjacent to the animals' noses

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Calculation of nominal concentrations: The nominal concentration was calculated from the study means of the test pump rates and the supply air flows used during exposure to generate the respective concentrations.
Online monitoring of the atmospheric concentration: The constancy of concentrations in the inhalation atmospheres were monitored continuously by calibrated online total hydrocarbon analyzer (TESTA FID 2010T in test group 0 and TESTA FID 123 in test groups 1-3) in all test groups including control. Using line recorders the measurements were recorded (see examples in Figure 003 in the APPENDIX) and the signals were transferred to the automated measuring system. The long-term drift of the online devices were checked by a weekly measurement of certificated test gas. To control the correctness of the calibrated devices and the identity of the test substance in the atmosphere, weekly two absorption samples per concentration were drawn from the atmospheres and were analyzed by gas chromatography (GC). The measured values of test group 0 served as blind control. The blind values were mainly the animals' gas emission and, in minor amount, directly from the atmosphere. Therefore, the concurrent blind values were substracted from the measured values. From the corrected daily mean values of each concentration, mean concentrations and standard deviations for the entire study were calculated.

Details on mating procedure:

- Impregnation procedure: artificial insemination
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: [vaginal plug / sperm in vaginal smear] referred to as [day 0 / day 1] of pregnancy
- Any other deviations from standard protocol:

Duration of treatment / exposure:

6 hours on workdays over a time period of 23 consecutive days (gestation days (GD) 6–28)

Frequency of treatment:

daily on workdays

Duration of test:

Until GD 29

Remarks:

Doses / Concentrations:
0, 5, 15, 45 ppm
Basis:
other: target concentration

Remarks:

Doses / Concentrations:
0, 17.6, 52.8, 158.4 mg/m³
Basis:
other: target concentration

Remarks:

Doses / Concentrations:
4.9, 15.7, 44.2 ppm
Basis:
analytical conc.

Remarks:

Doses / Concentrations:
17.4, 55.3, 155.6 mg/m³
Basis:
analytical conc.

Remarks:

Doses / Concentrations:
21.9, 57.2, 176.5 mg/m³
Basis:
nominal conc.

No. of animals per sex per dose:

25 inseminated female Himalayan rabbits

Control animals:

yes, sham-exposed

Details on study design:

- Dose selection rationale: Dose selection was requested by the sponsor.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Mortality was checked in the females twice a day on working days or once a day on Saturdays, Sundays or on public holidays (GD 0 29). During pre-flow period and on the day of necropsy the animals were examined for clinical symptoms at least once a day. During the exposure period, a clinical inspection of each animal was performed at least three times a day (before, during and after exposure). During the exposure procedure a groupwise examination was conducted.


BODY WEIGHT: Yes
- Time schedule for examinations: All animals were weighed on GD 0, 2, 4, 6, 9, 11, 14, 16, 19, 21, 23, 25, 28 and 29. The body weight change of the animals was calculated.
- Corrected (net) body weight gain: The corrected body weight gain was calculated after terminal sacrifice (terminal body weight on GD 29 minus weight of the unopened uterus minus body weight on GD 6).


FOOD CONSUMPTION: Yes
- The food consumption was determined daily on GD 1–29. Because of the malfunction of a balance, the food consumption was not properly recorded on 24 June 2008and the values from this day were not used for the calculation of means and were specified as “not measured / no value determinable”.


WATER CONSUMPTION AND COMPOUND INTAKE: No


POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 29
- Organs examined: weight assessment: lungs; histopathology: nasal cavities, larynx, trachea, lungs, mediastinal lymph nodes, all gross lesions

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Weight of the unopened uterus
- Number of corpora lutea
- Number and distribution of implantation sites classified as: 1) live fetuses; 2) dead implantations: a) early resorptions (only decidual or placental tissues visible or according to SALEWSKI (Salewski, 1964) from uteri from apparently non pregnant animals and the empty uterus horn in the case of single horn pregnancy); b) late resorptions (embryonic or fetal tissue in addition to placental tissue visible); c) dead fetuses (hypoxemic fetuses which did not breathe spontaneously after the uterus had been opened)
- Calculations of conception rate and pre- and postimplantation losses were carried out:
The conception rate (in %) was calculated according to the following formula: (number of pregnant animals)/(number of fertilized animals) x 100
The preimplantation loss (in %) was calculated based on each individual pregnant animal with scheduled sacrifice according to the following formula: (number of corpora lutea – number of implantations)/(number of corpora lutea) x 100
The postimplantation loss (in %) was calculated based on each individual pregnant animal with scheduled sacrifice from the following formula: (number of implantations – number of live fetuses)/(number of implantations) x 100

Fetal examinations:

- External examinations: Yes, all per litter
- Soft tissue examinations: Yes, all per litter
- Skeletal examinations: Yes, all per litter
- Head examinations: Yes, half per litter

Statistics:

DUNNETT-test (two-sided), FISHER'S EXACT test (one-sided), WILCOXON-test (one-sided), KRUSKAL-WALLIS test (two-sided)

Indices:

Calculations of conception rate and pre- and postimplimantation losses were carried out.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Only pregnant does were used for the calculations of mean maternal food consumption, body weight and body weight change. Only pregnant does with scheduled sacrifice (GD 29) were used for the calculation of mean gravid uterine weights, corrected (net) body weight gain and summary of reproduction data. On female each of test group 0 (0 ppm), test group 2 (15 ppm), and test group 3 (45 ppm)were excluded from the above-mentioned calculations since they were not pregnant. Thus, according to the requirements of the corresponding test guidelines, each test group including the controls contained a sufficient number of females with implantation sites at necropsy (approximately 20, but not fewer than 16 females with implantation sites).

- Mortality: There were no test substance-related or spontaneous mortalities in any group.
- Clinical symptoms: No test substance-related clinical signs or any disturbances of the general behavior were observed in any rabbit during the entire study period.
- Food consumption: The average food consumption was comparable to the control group in all test groups (5, 15 and 45 ppm) and did not show a test substance-related impairment. Differences between control rabbits and test substance-treated rabbits did not show a relation to dosing and were considered to be without biological relevance. This overall statement is true in spite of the slightly but significantly lower high-dose value on GD 23-24.
- Body weight data: The average body weights and body weight gain were comparable among control and treated groups (5, 15 and 45 ppm) during the entire study. All observable differences in the treated groups in comparison to the controls are without any biological relevance. This statement includes the statistically significatly decreased body weight gain in test group 3 on GD 9-11.
- Corrected (net) body weight gain: The results of the corrected body weight gain (terminal body weight on GD 29 minus weight of the unopened uterus minus body weight on GD 6) revealed no difference of biological relevance between the test substance-treated groups and the control group. Mean carcass weights remained also unaffected by the treatment.
- Uterus weight: The mean gravid uterus weights of the animals of all test groups (5, 15 and 45 ppm) were not influenced by the test substance. The differences between these groups and the control group revealed no dose-dependency and were assessed to be without biological relevance. Considering the fluctuations in the mean number of live fetuses/doe, they reflect the normal degree of variation for rabbits of the strain used in this study.
- Reproduction data of does: The conception rate reached 96% in test groups 0, 2 and 3 (0, 15 or 45 ppm) and 100% in test group 1 (5 ppm). Importantly, a sufficient number of pregnant females was available for the purpose of the study, as 24-25 pregnant rabbits per group had implantation sites in the uterus. There were no test substance related and/or biologically relevant differences between the different test groups in conception rate, in the mean number of corpora lutea and implantation sites or in the values calculated for the pre- and the postimplantation losses, the number of resorptions and viable fetuses. Generally, gestational parameters in the various test groups were within the normal range for animals of this strain and age, see also Part III (Supplement) for historical control data.

Dose descriptor:

NOAEC

Effect level:

0.055 mg/L air (analytical)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEC

Effect level:

0.156 mg/L air (analytical)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
- Sex distribution of fetuses: The sex distribution of the fetuses in test groups 1-3 (5, 15 and 45 ppm) was comparable to the control fetuses. Observable differences were without biological relevance.
- Weight of placentae: The mean placental weights in test groups 1, 2 and 3 (5, 15 and 45 ppm) were comparable to the controls.
- Weight of fetuses: The mean fetal weights of all treated groups were not influenced by the test substance. Neither female nor male fetal weights showed statistically significant or biologically relevant differences between the test substance-treated groups and the controls.
- Fetal external malformations: Three external malformations, which were associated with corresponding soft tissue and skeletal malformations, were recorded for single fetuses of test groups 1 and 2 (5 or 15 ppm). Because a dose-response relationship was missing these findings were considered to be spontaneous in nature.
- Fetal external variations: One external variation (paw hyperflexion) occurred in single fetuses of all treated groups and the control. The incidences did not demonstrate a dose-response relationship and were comparable to the historical control data. Thus an association of this finding to the treatment is not assumed.
- Fetal external unclassified observations: One unclassified external observation, i.e. blood coagulum around placenta, was recorded for one fetus of the control group and was spontaneous in nature.
- Fetal soft tissue malformations: The examination of the soft tissues revealed three malformations in single fetuses of all treated groups (5, 15 and 45 ppm). Although no findings were observed in the control and the rate of affected fetuses per litter was significantly higher in the low- and mid-dose groups, no dose related increase of the incidence of soft tissue malformations was noted. Apart from the single incidental case of small cerebrum the findings occurred at incidences comparable to the historical control data. Thus an association of the soft tissue findings to the treatment is not assumed.
- Fetal soft tissue variations: Three soft tissue variations, such as absent lung lobe (lobus inferior medialis), malpositioned carotid branch and dilated cerebral ventricle, were detected in each test group including the controls without relation to dosing. Neither statistically significant differences between the test groups nor differences to the historical control data were noted.
- Fetal soft tissue unclassified observations: Unclassified soft tissue observations, such as discolored kidney, blood coagulum around urinary bladder and hemorrhagic ovary, were recorded for some fetuses of all test groups (0, 5, 15 and 45 ppm). A relation to dosing is not present if normal biological variation is taken into account. Therefore, a test substance-induced effect is not assumed.
- Fetal skeletal malformations: Malformations of the fetal skeletons were observed in fetuses of all test groups including the controls (0, 5, 15 and 45 ppm). Neither statistically significant differences between treated groups and control nor a dose-response relationship were noted. When calculated on a fetus per litter basis, the overall incidence of skeletal malformations was comparable to the historical control data. This is also true for the severely fused sternebrae (bony plate), where the incidence of affected fetuses per litter in the high-dose group was also slightly but statistically significantly higher than the concurrent control.
- Fetal skeletal variations: For all test groups, variations were detected in different skeletal structures with or without effects on corresponding cartilaginous structures. The observed skeletal variations were related to various parts of the fetal skeleton and appeared without a relation to dosing. The overall incidences of skeletal variations were comparable to the historical control data. Two isolated skeletal variations were statistically significantly higher than the concurrent and/or outside the historical control (on a fetus per litter basis). These findings are delays of ossification which is reversible and does not affect the morphology of the cervical vertebra as it becomes obvious by the unchanged underlying cartilage. Such slight retardations of the ossification process occur very frequently in gestation day 29 rabbit fetuses of this strain. Also, the increased incidences are not at all related to the dose. Thus, these findings are regarded to be of no biological relevance.
- Fetal skeletal unclassified cartilage observations: Additionally, some isolated cartilage findings without impact on the respective bone structures, which were designated as unclassified cartilage observations, occurred in all groups including the control. The observed unclassified cartilage findings did not show a relation to dosing and were considered to be spontaneous in nature.
- Summary of all classified fetal external, soft tissue and skeletal observations: Various external, soft tissue and skeletal malformations occurred throughout all test groups including the control. They did neither show a consistent pattern since a number of morphological structures of different ontogenic origin were affected nor a clear dose-response relationship. Furthermore, the overall incidences were comparable to the historical control data. Thus, non of the malformations was considered to be related to the treatment. One external (paw hyperflexion), three soft tissue (absent lobus inferior medialis, malpositioned carotid branch and dilated cerebral ventricle) and a broad range of skeletal variations occurred in all test groups including the controls. All fetal and litter incidences for these variations and the corresponding mean percentages of affected fetuses/litter did not show a relation to dosing. In addition, they can be found at a comparable frequency in the historical control data. Therefore, they were not considered to be related to the treatment.

Abnormalities:

not specified

Developmental effects observed:

not specified

- Study means and standard deviations of test substance concentrations:

Test group	Target concentration		Measured concentration (FID)				Nominal concentration (mg/m³)	Effectiveness of vapor generation (%)
			(ppm)		(mg/m³)
	ppm	mg/m³	Mean	SD	Mean	SD
0	0	0	-	-	-	-	-	-
1	5	17.6	4.9	1.1	17.4	3.9	21.9	79.5
2	15	52.8	15.7	1.8	55.3	6.2	57.2	96.8
3	45	158.4	44.2	1.2	155.6	4.3	176.5	88.2

- = not measured

- Occurrence of statistically significantly increased fetal skeletal variation (expressed as mean percentage of affected fetuses/litter):

Finding	Test group 0 0 ppm	Test group 1 5 ppm	Test group 2 15 ppm	Test group 3 45 ppm	HCD Mean % (range)
Incomplete ossification of cervical centrum; unchanged cartilage	1.9	8.9**	4.9	6.1	2.2 (0.0–5.0)
Incomplete ossification of sacral arch; cartilage present	0.0	0.7	1.9*	1.2	0.3 (0.0–2.2)

ppm = parts per million; HCD = Historical control data

* = p≤0.05, ** = p≤0.01 (Wilcoxon-Test [one-sided])

- Total fetal malformations: 

		Test group 0 0 ppm	Test group 1 5 ppm	Test group 2 15 ppm	Test group 3 45 ppm
Litter Fetuses	N N	24 144	25 171	24 150	24 136
Fetal incidence	N (%)	3 (2.1%)	8 (4.7%)	7 (4.7%)	6 (4.4%)
Litter incidence	N (%)	3 (13%)	6 (24%)	6 (25%)	6 (25%)
Affected fetuses/ litter	Mean%	1.9	4.0	4.6	3.7

ppm = parts per million; N = number; % = per cent

- Total fetal variations:

		Test group 0 0 ppm	Test group 1 5 ppm	Test group 2 15 ppm	Test group 3 45 ppm
Litter Fetuses	N N	24 144	25 171	24 150	24 136
Fetal incidence	N (%)	96 (67%)	123 (72%)	119 (79%)	83 (61%)
Litter incidence	N (%)	24 (100%)	25 (100%)	24 (100%)	23 (96%)
Affected fetuses/litter	Mean%	68.8	71.9	77.9	60.5

ppm = parts per million; N = number; % = per cent

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

155.6 mg/m³

Study duration:

subchronic

Species:

rabbit

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

No developmental toxicity studies are available for 2-propylheptyl acrylate.From the structurally analogous substances 2 -ethylhexyl acrylate (CAS No. 103-11-7) and methyl acrylate (CAS No. 96-33-3) developmental toxicity studies are available and read across approach was performed.

Saillenfait et al., 1999, rat

In a published developmental study the structural analogue 2-ethylhexyl acrylate was investigated. Groups of 25 pregnant rats inhaled 0, 50, 75 or 100 ppm 2-ethylhexyl acrylate (corresponding to approx.0.38, 0.56 and 0.75 mg/L) for 6 h/day from days 6 through 20 of gestation. Marked maternal toxicity was demonstrated at 100 ppm as pronounced decreases in maternal body weight gain and food consumption over the entire exposure period. There were no treatment related increases in embryo/fetal mortality and no fetal malformations were observed in any of the treatment groups (Saillenfait 1999). The NOAEC for maternal toxicity was 75 ppm (0.56 mg/L), and the NOAEC for developmental effects (teratogenicity) was the highest concentration tested of 100 ppm (0.75 mg/L).

In the same published study, groups of 25 pregnant rats inhaled 0, 25, 50 or 100 ppm methyl acrylate (corresponding to approx.0.089, 0.179, 0.357 mg/L) for 6 h/day from days 6 through 20 of gestation. Marked maternal toxicity was demonstrated at 50 and 100 ppm as pronounced decreases in maternal body weight gain and food consumption over the entire exposure period. There were no treatment related increases in embryo/fetal mortality and no fetal malformations were observed in any of the treatment groups. Fetal toxicity, indicated by significantly reduced fetal body weight, was observed after exposure to 100 ppm methyl acrylate in the presence of overt signs of maternal toxicity (Saillenfait 1999). The NOAEC for maternal toxicity was 25 ppm (0.089 mg/L), the NOAEC for developmental effects (fetotoxicity) was 50 ppm (0.179 mg/L), and the NOAEC for developmental effects (teratogenicity) was the highest concentration tested of 100 ppm (0.357 mg/L).

BASF SE, 2009, rabbit

Additionally, a prenatal developmental toxicity study in rabbits as second species was conducted with methyl acrylate according to OECD TG 414 for the Acrylate Task Force (BASF SE 2009). 25 inseminated female Himalayan rabbits per group were whole-body exposed for 6 hrs/day, 5 days/week over a time period of 23 consecutive days (gestation days (GD) 6–28) to methyl acrylate vapours at target concentrations of 0, 5, 15, and 45 ppm. Analytical concentrations of 4.9, 15.7, 44.2 ppm (corresponding to approx. 0.0174, 0.0553, 0.1556 mg/L) were measured. On gestation day 29 the does were sacrificed and submitted to gross and histopathological examination (nasal cavities, larynx, trachea, lungs, mediastinal lymph nodes, all gross lesions). Examinations of ovaries and uterine content of the does included: determination of the weight of the unopened uterus, of the number of corpora lutea, of the number and distribution of implantation sites, and calculations of conception rate and pre- and post-implantation losses.Fetal examinations were performed on all fetuses per litter (external, soft tissue, skeletal) except head examinations that were done on half of the fetuses per litter. There were no test substance-related effects concerning food consumption, gross/net body weight, gestational parameters, uterine, placental and lung weights, as well as necropsy observations up to and including a dose of 45 ppm. The test substance caused a severe degeneration and atrophy of the olfactory epithelium at at least one focal area in the nasal cavity (distal levels III and/or IV) at the high-dose level (45 ppm). Though being local effects, such massive findings in the respiratory tract are likely to cause a considerable amount of distress in the affected maternal animals. Since distress is supposed to influence maternal homeostasis, this is considered to be a significant adverse effect on the maternal organism. The NOAEC for maternal toxicity was 15 ppm (0.0553 mg/L). Fetal examinations revealed no influence of the test compound on sex distribution of the fetuses and fetal body weights. Methyl Acrylate (MA) had no adverse effect on prenatal development of offspring at any of the dose levels tested (5, 15 and 45 ppm). Thus, the NOAEC for developmental effects (fetotoxicity) and the NOAEC for developmental effects (teratogenicity) was the highest concentration tested of 45 ppm (0.1556 mg/L).

Conclusion

As no studies regarding developmental toxicity are available for propylheptyl acrylate, studies with analogous substances were used to assess the test substance. Methyl acrylate is the smallest analogue out of the series of acrylic acid esters. The read across statement (refer to IUCLID section 13) shows that a smaller alkyl tail leads to a higher reactivity regarding water solubility, log Pow, etc. Therefore it can be concluded that testing methyl acrylate is a worst case scenario. 100 ppm (357 mg/m^3) was the highest concentration tested in a study with pregnant rats and did not evolve developmental toxicological effects. Further a teratogenicity study with rabbits did not result in any effects up to the highest tested concentration of methyl acrylate (155.6 mg/m^3). A supporting argument is the result of the rat study with ethylhexyl acrylate, a structurally more related compound to propylheptyl acrylate. The highest tested dose was 100 ppm (750 mg/m^3) and did not lead to any developmental toxicity. Therefore it can be concluded that propylheptyl acrylate has no influence on the development of rat pups.

Justification for selection of Effect on developmental toxicity: via inhalation route:
GLP and guideline compliant study.

Justification for classification or non-classification

According to the results of the above mentioned studies, 2-propylheptyl acrylate is not subjected to classification and labelling according to Directive 67/548/EEC (DSD) and Regulation (EC) No 1272/2008 (CLP/GHS).