Bis(2-ethylhexyl) maleate

Toxicity to reproduction

Administrative data

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was evaluated under the OECD SIDS program and scored as reliability 1b: Reliable without restriction; comparable to guideline study read across rationale is attached in IUCLID section 13 Assessment reports

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

publication

Title:

Teratology and multigeneration reproduction studies with maleic anhydride in rats

Author:

Short RD, Johannsen FR, Levinskas G J, Rodwell DE, Schardein JL

Year:

1986

Bibliographic source:

Fundam. Appl. Toxicol. 7: 359-366

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 416 (Two-Generation Reproduction Toxicity Study)

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Maleic anhydride

EC Number:

203-571-6

EC Name:

Maleic anhydride

Cas Number:

108-31-6

Molecular formula:

C4H2O3

IUPAC Name:

furan-2,5-dione

Constituent 2

Reference substance name:

2,5-Furandione

IUPAC Name:

2,5-Furandione

Test material form:

other: briquettes

Details on test material:

- Name of test material (as cited in study report): Maleic anhydride
- Molecular formula (if other than submission substance): C4H2O3
- Molecular weight (if other than submission substance): 98.06 g/mol
- Smiles notation (if other than submission substance): O=C1OC(=O)C=C1
- InChl (if other than submission substance):
- Structural formula attached as image file (if other than submission substance): see Fig. 1
- Physical state: white solid (briquette)
- Analytical purity: >99%

Test animals

Species:

rat

Strain:

CD-1

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories
- Age at study initiation: (P) 5-6 wks; (F1) 22 days
- Housing: Besides mating: males were housed individually in wire-mesh cages, female were housed individually in plastic cages. During the mating period, each male was housed with two females
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: Animals were acclimated to for at least 10 days

ENVIRONMENTAL CONDITIONS
Animals were maintained in environmentally controlled rooms with a photoperiod of 12 hrs dark / 12 hrs light

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

The test substance was suspended in corn oil. The applied dose volume was 10 ml/kg

Details on mating procedure:

- M/F ratio per cage: 1/2
- Length of cohabitation: up to 15 days
- Proof of pregnancy: vaginal plug or sperm in vaginal smear referred to as day 0 of pregnancy
- After successful mating each pregnant female was caged individually in plastic cages with nesting material

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

A minimum of 80 days (each generation)

Frequency of treatment:

Daily treatment, 7 days / week

Details on study schedule:

Femals of the F0 generation were bred twice with males of the same generation to produce the genarations F1a and F1b. From the Fb1 generation, 10 males and 20 females were selected randomly to produce generations F2a and F2b.

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

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
0 mg/kg/day
Basis:
nominal conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
20 mg/kg/day
Basis:
nominal conc.

Doses / concentrations 3

Remarks:

Doses / Concentrations:
55 mg/kg/day
Basis:
nominal conc.

Doses / concentrations 4

Remarks:

Doses / Concentrations:
150 mg/kg/day
Basis:
nominal conc.

No. of animals per sex per dose:

10 males, 20 females

Control animals:

yes, concurrent vehicle

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes

DETAILED CLINICAL OBSERVATIONS: Yes

BODY WEIGHT: Yes

All parameters were recorded at intervals. No more details are given

Oestrous cyclicity (parental animals):

no data

Sperm parameters (parental animals):

no data

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: yes
- If yes, maximum of 10 pups/litter (5/sex/litter as nearly as possible).

Postmortem examinations (parental animals):

Yes

Postmortem examinations (offspring):

Yes

Statistics:

Analysis of variance and Dunnett's test for adult body weights and litter size
Fisher's exact probability test for mortality and fertility
Level of significance: p<0.05

Reproductive indices:

not reported

Offspring viability indices:

not reported

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

not specified

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

renal cortical necrosis in males and females of the F0 group from the high-dose group

Other effects:

effects observed, treatment-related

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not specified

Reproductive function: sperm measures:

not specified

Reproductive performance:

not specified

Details on results (P0)

With the exception of a few cases of respiratory rales, the clinical appearance and behavior of the F0 rats were not remarkably different from those of their controls. Respiratory rales also occurred in F1 rats, and the incidence and severity appeared to increase with dose. In addition, rats of the F1 generation often vigorously resisted handling at the time of dosing. This behavior may be related to irritating effects of maleic anhydride or a taste aversion to the test material. In the F0 and F1 generation, significant mortality occurred in adults of both sexes from the high-dose group, but the F1 generation had a greater number of deaths, many of which were attributed to gavage-related injuries. If these traumatic deaths are omitted, mortality in the F1 generation tended to parallel that of the F0 generation except for the increase recorded for low-dose males. One animal in the F0 group died of interstitial pneumonia. While no cause could be identified, the three other deaths in this group are not believed to be compound-related because no deaths among mid-dose males were attributed to the test material and characteristic compound-induced lesions discussed subsequently were not noted.
Adult body weights were not affected in the low-dose groups of F0 and F1. While there were some differences in mean body weights between control animals and those of the mid-dose group, none of the differences was statistically significant. In the high-dose group, mean body weights of both sexes of the F0 generation were significantly reduced by Week 11, and this reduction persisted for the remainder of the test. The F1 generation showed a pattern that was roughly similar, except that the only significantly depressed mean body weight occurred in high-dose males at 30 weeks.
Fertility was significantly reduced in the all experimental groups at several times. However, there was neither a dose-related reduction nor a pattern within a generation hat suggested the presence of a treatment-reated effect

Effect levels (P0)

1

Dose descriptor:

NOAEL

Effect level:

55 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: overall effects

Remarks on result:

other: Generation: for two generations (migrated information)

2

Dose descriptor:

NOAEL

Effect level:

55 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: fertility

Remarks on result:

other: Generation: two generations (migrated information)

3

Dose descriptor:

dose level: highest dose level

Effect level:

150 mg/kg bw/day

Based on:

test mat.

Sex:

not specified

Basis for effect level:

other: At the highest test concentration of 150 mg/kg/day, maleic anhydride was toxic to parental animals.

Remarks on result:

other: Generation: parental animals (migrated information)

Results: F1 generation

General toxicity (F1)

Clinical signs:

not specified

Mortality / viability:

not specified

Body weight and weight changes:

effects observed, treatment-related

Sexual maturation:

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Increase of kidney weights in females of tghe F1 generations at the low- and mid-dose group

Gross pathological findings:

no effects observed

Histopathological findings:

no effects observed

Details on results (F1)

Respiratory rales as recorded for F0 also occurred in F1 rats, and the incidence and severity appeared to increase with dose. The F1 generation had a greater number of deaths than F0, many of which were attributed to gavage-related injuries. If these traumatic deaths are omitted, mortality in the F1 generation tended to parallel that of the F0 generation except for the increase recorded for low-dose males. As for F0, adult body weights were not affected in the low-dose groups. While there were some differences in mean body weights between control animals and those of the mid-dose group, none of the differences was statistically significant. Fertility was significantly reduced in the experimental groups at several times. However, there was neither a dose-related reduction nor a pattern within a generation hat suggested the presence of a treatment-reated effect

Effect levels (F1)

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

150 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: litter size

Results: F2 generation

Effect levels (F2)

Dose descriptor:

NOAEL

Generation:

F2

Effect level:

55 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: litter size

Overall reproductive toxicity

Reproductive effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Under the conditions of the test it can be concluded that maleic anhydride does not show any reprotoxic effects at a test concentration up to 55 mg/kg bw/day.

Executive summary:

Microscopic (MC) examination of F0 showed changes in the kidneys (renal cortical necrosis) of rats at 150 mg/kg bw/day; F1 female adults had significant increase in absolute kidney weights at 20 and 55 mg/kg bw/day, without MC changes; F2a and b did not show organ weight changes or in incidences of MC lesions. MA was toxic at 150 mg/kg bw/day.

Based on lack of significant reduction in pregnant females or fertile males was observed NOEL (fertility) 55 mg/kg bw/day over two generations and NOEL (offsprings) 55 mg/kg/bw/day.

According to Annex IX, 8.7.3 column 1, the test is only required if the 28 day or 90 day study indicated adverse effects on reproductive organs or tissues. However there is no evidence of reproductive and developmental toxicity in any of the tests available including a 28-day (OECD 422) and 90-day (OECD 408) oral studies in rats. Thus further studies to cover this endpoint are not required.