reaction products of acetic anhydride and adipic acid

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Link to relevant study records

Reference

Endpoint:

toxicity to reproduction

Remarks:

other: chronic two-year study

Type of information:

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

Adequacy of study:

weight of evidence

Study period:

1957

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

No GLP, short documentation, unclear number of animals examined histopathologically, only one dose for females, purity not specified. Read-across justification: The available toxicological data for the target and source substances is outlined in the data matrix (Annex I). The toxicological properties of the target substance are related mainly to acetic acid/acetate since the anhydride components of the substance are hydrolytically unstable. When the target substance comes in contact with water or moisture a complete hydrolysis will take place to form no other hydrolysis products than acetic acid/acetate and adipic acid. Thus, the use of data from acetic acid and adipic acid is justified to evaluate toxicological properties of the target substance. Furthermore, data from acetic anhydride is used in the assessment. Experimental data obtained with the source substances indicate that the substances has low oral (LD50 > 1780 – 3310 mg/kg bw) and inhalation (LC50 1680 - 7700 mg/m3) acute toxicity. Furthermore, the acetic acid and acetic anhydride are irritating to skin at concentration < 25% and corrosive to skin at ≥ 25%. Acetic anhydride and acetic acid are not tested for sensitisation due corrosive properties; adipic acid did not show any evidence of sensitising in an animal study. The source substances did not show positive response in genetic toxicity studies available. Repeated toxicity studies via oral route conducted for acetic acid showed NOAEL values ≥ 210 mg kg bw/day and via inhalation route for acetic anhydride 4.2 mg/m3.. Reproduction toxicity studies conducted for acetic acid did not show any adverse effects on reproduction at the highest concentration tested (1600 mg/kg bw/day).

Principles of method if other than guideline:

Rats were fed either the basal laboratory diet, or the basal diet to which adipic acid was added. Body weights, food consumption, and general appearance were recorded weekly throughout the experimental period. Whenever possible, gross autopsy was performed on those animals that died during the course of the experiment. After two years, surviving rat were weighed, killed, and examined grossly. Organs were weighed. Microscopic examination of several organs, including testis or ovaries and uterus was performed on a representative number of animals.

GLP compliance:

no

Species:

rat

Strain:

other: Carworth Farm strain

Sex:

male/female

Route of administration:

oral: feed

Details on mating procedure:

no mating

Duration of treatment / exposure:

Exposure period: 2 years

Frequency of treatment:

diet ad libitum

Details on study schedule:

2 year cancer study

Remarks:

Doses / Concentrations:
male rats: 0, 0.1, 1, 3, and 5%; (ca. 75, 750, 2250, 3750 mg/kg bw/day) female rats: 0, 1%; (ca. 750 mg/kg bw/day)
Basis:

No. of animals per sex per dose:

19-20 per sex and dose

Control animals:

yes

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

eight gains for the male rats receiving 3 or 5% adipic acid was significantly less than the controls.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

eight gains for the male rats receiving 3 or 5% adipic acid was significantly less than the controls.

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

histopathologic examination of the testes, ovaries and uterus revealed no evidence of an adverse effect on the reproductive organs.

Dose descriptor:

NOAEL

Effect level:

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

Sex:

female

Dose descriptor:

NOAEL

Effect level:

3 750 mg/kg bw/day (actual dose received)

Sex:

male

Reproductive effects observed:

not specified

Conclusions:

In an two-years feeding study in rats histopathological examination of testes, ovaries and uterus revealed no evidence of an adverse
effect on the reproductive organs up to the highest doses tested (males approx. 3750 mg/kg bw/day, females approx. 750 mg/kg bw/day).

Executive summary:

Studies on fertility are not available. In the two-years feeding study in rats histopathological examination of testes, ovaries and uterus revealed no evidence of an adverse effect on the reproductive organs up to the highest tested doses (3750 mg/kg bw/day in males, 750 mg/kg bw/day in females). Soft edematous testes were observed at least as frequent in the controls as in the adipic acid dosed animals. Two of the surviving control female animals and one of the experimental females had ovarian

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

750 mg/kg bw/day

Study duration:

chronic

Species:

rat

Effect on fertility: via inhalation route

Endpoint conclusion:

no adverse effect observed

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Acetic anhydride

In the subchronic study male and female rats were exposed to acetic anhydride vapor (0, 1, 5, or 20 ppm) for 13 weeks for 6 hrs/day, 5 days/week OECD; SIDS (1997). No significant adverse effects were observed on comprehensive, microscopic examination of the reproductive organs of male rats.

 

Adipic acid

In the two-years feeding study in rats histopathological examination of testes, ovaries and uterus revealed no evidence of an adverse effect on the reproductive organs up to the highest tested doses (3750 mg/kg bw/day in males, 750 mg/kg bw/day in females) (Horn et al. 1957). Soft edematous testes were observed at least as frequent in the controls as in the adipic acid dosed animals. Two of the surviving control female animals and one of the experimental females had ovarian tumors, ovarian cysts were noted in both control and experimental rats.

Short description of key information:
No studies were identified to assess the potential impact of the target substance on reproduction/fertility. Further relevant information to evaluate the toxicity to reproduction is available from the studies conducted for the components/hydrolysis products of the target substance.

The data from a subchronic study conducted for acetic anhydride (OECD; SIDS 1997), from a chronic study conducted for adipic acid (OECD; SIDS, 2004; Horn, et al. 1957) and from the toxicokinetic evaluation of the target substance, indicates that this substance has no effects on fertility. Furthermore, as shown by Morfareidge (1974), acetic acid did not cause developmental toxicity in oral studies with rabbits, rats or mice at dose levels up to 1.6g when 5 % acetic acid/kg/day administered during days 6-18 (rabbit) or 6-15 (rats, mice) of gestation.

The available studies are sufficient in their design and quality to draw the conclusion that there is no evidence to suggest that the target substance would present adverse effects on fertility.

Justification for selection of Effect on fertility via oral route:
No oral study conducted for the substance itself. A reliable chronic study is available for the degradation product of the target substance.

Justification for selection of Effect on fertility via inhalation route:
No inhalation study available for the substance itself. No study was selected since WoE approach was used to assess the effects on fertility via inhalation route.

Justification for selection of Effect on fertility via dermal route:
No dermal study available for the substance itself or constituents/degradation products. Not a likely exposure route. As the substance is classified for skin corrosive appropriate RMMs need to be worn to prevent dermal exposure.

Effects on developmental toxicity

Description of key information

No studies were identified to assess the potential impact of the target substance on reproduction/development. Thus, further relevant information to evaluate the toxicity to reproduction is available from the studies conducted for the constituents/hydrolysis products of the target substance.
Acetic acid did not cause developmental toxicity in oral studies with rabbits, rats or mice at dose levels up to 1.6g 5% acetic acid/kg/day administered during days 6-18 (rabbit) or 6-15 (rats, mice) of gestation (Morfareidge, K. (1974). 
No Systemic effects were observed when rats were exposed to acetic anhydride for 13 weeks at 5 or 20 ppm (OECD; SIDS 1997).
Adipic acid did not show any fetotoxic or teratogenic properties in chronic study in mice, rats and rabbits (OECD; SIDS,2004)
The available studies are sufficient in their design and quality to draw the conclusion that there is no evidence to suggest that the target substance would present adverse effects on development.

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:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP status not known, near guideline study, published in peer reviewed literature, limitations in design and/or reporting but otherwise adequate for assessment. Read-across justification: The available toxicological data for the target and source substances is outlined in the data matrix (Annex I). The toxicological properties of the target substance are related mainly to acetic acid/acetate since the anhydride components of the substance are hydrolytically unstable. When the target substance comes in contact with water or moisture a complete hydrolysis will take place to form no other hydrolysis products than acetic acid/acetate and adipic acid. Thus, the use of data from acetic acid and adipic acid is justified to evaluate toxicological properties of the target substance. Furthermore, data from acetic anhydride is used in the assessment. Experimental data obtained with the source substances indicate that the substances has low oral (LD50 > 1780 – 3310 mg/kg bw) and inhalation (LC50 1680 - 7700 mg/m3) acute toxicity. Furthermore, the acetic acid and acetic anhydride are irritating to skin at concentration < 25% and corrosive to skin at ≥ 25%. Acetic anhydride and acetic acid are not tested for sensitisation due corrosive properties; adipic acid did not show any evidence of sensitising in an animal study. The source substances did not show positive response in genetic toxicity studies available. Repeated toxicity studies via oral route conducted for acetic acid showed NOAEL values ≥ 210 mg kg bw/day and via inhalation route for acetic anhydride 4.2 mg/m3.. Reproduction toxicity studies conducted for acetic acid did not show any adverse effects on reproduction at the highest concentration tested (1600 mg/kg bw/day).

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method B.31 (Prenatal Developmental Toxicity Study)

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

Virgin adult female albino rats (Wistar derived stock) were individually housed in mesh bottom cages in temperature and humidity controlled quarters with free access to food and fresh tap water.

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

The females were dosed with the indicated dosages by oral intubations. The controls were sham treated with the vehicle at a level equivalent to the group receiving the highest test dose. The test material was prepared and doses calculated according to the following table:

Dosage Dose Concentration
(mg/kg) (ml/kg) (mg/ml)
250 1 250
251 - 540 2 125 - 250
501 - 750 3 133 - 250
751 - 1000 4 187 - 250
1001 - 1250 5 200 - 250
1251 - 1500 6 208 - 250
1501 - 1600 6.4 235 - 250

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

The females were mated with young adult males, and observation of the vaginal sperm plug was considered Day 0 of gestation.

Duration of treatment / exposure:

Days 6 - 15 of gestation

Frequency of treatment:

Daily

Duration of test:

Days 0-20 of gestation

Remarks:

Doses / Concentrations:
0, 16, 74.3, 345, 1600 mg/kg/day
Basis:
nominal conc.

No. of animals per sex per dose:

25 mated females

Control animals:

yes, sham-exposed

Details on study design:

An additional group of mated females was dosed with 150 mg/kg aspirin and served as a positive control

Maternal examinations:

Body weights were recorded on Days 0, 6, 11, 15, and 20 of gestation.
All animals were observed daily for appearance and behaviour with particular attention to food consumption and weight, in order to rule out any abnormalities which may have occurred as a result of anorexic effects in the pregnant female animal

Ovaries and uterine content:

On Day 20 all dams were subjected to Caesarean section under surgical anesthesia, and the numbers of implantation sites, resorption sites, and live and dead fetuses were recorded. The urogenital tract of each dam was examined in detail for anatomical normality.

Fetal examinations:

The body weights of the live pups were recorded. All fetuses were examined grossly for the presence of external congenital abnormalities. One-third of the fetuses of each litter underwent detailed visceral examinations employing the Wilson technique. The remaining two-thirds were cleared in potassium hydroxide, stained with alizarin red S dye and examined for skeletal defects.

Details on maternal toxic effects:

Details on maternal toxic effects:
The administration of up to 1600 mg/kg (body weight) of the test material to pregnant rats for 10 consecutive days had no clearly discernible effect on nidation or on maternal survival.

Dose descriptor:

NOAEL

Effect level:

1 600 mg/kg bw/day

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
The administration of up to 1600 mg/kg (body weight) of the test material to pregnant rats for 10 consecutive days had no clearly discernible effect on fetal survival. The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the number occurring spontaneously in the sham-treated controls.

Abnormalities:

not specified

Developmental effects observed:

not specified

Conclusions:

The administration of up to 1600 mg/kg (body weight) to pregnant rats for 10 consecutive days had no clearly discernible effect on nidation or on maternal or fetal survival. The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the number occurring spontaneously in the sham-treated controls.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 600 mg/kg bw/day

Study duration:

chronic

Species:

rat

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no adverse effect observed

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Acetic anhydride

Pregnant female rats were exposed to acetic anhydride at concentration of 0, 25, 100 or 400 ppm for 6 hrs/day, during days 6-15 of gestation (OECD; SIDS, 1997). Acetic anhydride caused fetotoxicity at maternally toxic dose of 100 ppm. At 100 ppm, severe respiratory tract irritation and bodyweight reduction were observed in the maternal animals. No developmental or reproductive effects were seen at 25 ppm even though substantial irritation of the respiratory tract was observed in maternal animals. The NOEL for developmental/reproductive effects was considered to be 25 ppm.

In the subchronic study male and female rats were exposed to acetic anhydride vapor (0, 1, 5, or 20 ppm)for 13 weeks for 6 hrs/day, 5 days/week. Clinical observations of eye and respiratory tract irritation and reduced body weights were observed primarily at 20 ppm. Microscopic examination of tissue revealed signs of irritation of minimal severity in the respiratory tract (nasal passages; larynx) in most animals at the 5 ppm level. Systemic effects were not observed at 5 or 20 ppm. No significant adverse effects were observed on comprehensive, microscopic examination of the reproductive organs of male rats.

 

Acetic acid

Apple cider vinegar (5 % acetic acid) was administered at doses 16, 74.3, 345 and 1600 mg/kg (body weight) to pregnant mice, rats and rabbits for 10, 10 and 13 consecutive days, respectively Morfareidge, K. (1974). The test substance had no clearly discernible effect on nidation or on maternal or fetal survival at any dose levels studied. The number of abnormalities seen in either soft or skeletal tissues of the test groups did not differ from the number occurring spontaneously in the sham-treated controls.

 

Adipic Acid

Adipic acid was not embryo- or fetotoxic and not teratogenic up to the highest tested doses of 288, 263 and 250 mg/kg bw/day via oral administration to rats, mice and rabbits, respectively. In none of these studies signs of maternal toxicity have been observed (OECD; SIDS, 2004).

Justification for selection of Effect on developmental toxicity: via oral route:
No oral study conducted for the substance itself. A reliable chronic study is available for the constituent/hydrolysis product of the target substance.

Justification for selection of Effect on developmental toxicity: via inhalation route:
No inhalation study available for the substance itself. No study was selected since WoE approach was used to assess the effects on development via inhalation route.

Justification for selection of Effect on developmental toxicity: via dermal route:
Not a likely exposure route. As the substance is classified for skin corrosive appropriate RMMs need to be worn to prevent dermal exposure.

Justification for classification or non-classification

Based on the results available of the constituents/hydrolysis products of the target substance there is no evidence to suggest that it would present adverse effects on fertility or development. Therefore, the target substance will not be classified for reproductive toxicity in accordance with the criteria of CLP Regulation 1272/2008.