Bis(16-methylheptadecyl) malate

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Effect on fertility: via oral route

Endpoint conclusion:

no study available

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

Toxicity to reproduction

According to Regulation (EC) No 1907/2006, Annex VIII, 8.7.1., column 2, a screening test for reproductive/developmental toxicity is not required as a test for prenatal developmental toxicity (Annex IX, 8.7.2) is available for the structural related substance Bis(2-ethylhexyl) adipate (CAS 103-23-1) which will be used for read-across. On the basis of this prenatal developmental toxicity study slight maternal toxicity was observed at the highest dose tested (1080 mg/kg bw/day) based on a small but statistically significant reduction in maternal bodyweight gain and food consumption. No signs of developmental toxicity were observed at any dose level resulting in a NOAEL of ≥1080 mg/kg bw/day.

Short description of key information:
Data waiving - Screening test for reproductive/developmental toxicity

Effects on developmental toxicity

Description of key information

Developmental Toxicity / teratogenicity (OECD 414), rat NOAEL (maternal) = 170 mg/kg bw/day; NOAEL (developmental) ≥1080 mg/kg bw/day (RA from CAS 103-23-1)

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:

15 Sep - 16 Oct 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP - guideline study. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (December 2012)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

other: Alpk:APfSD (Wistar derived)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: SPF colony maintained at the Animal Breeding Unit, ICI Pharmaceuticals, Alderley Park, Cheshire, UK.
- Age at study initiation: 12 weeks
- Weight at study initiation: 218-278 g
- Housing: individually in stainless steel cages with absorbent paper over collecting trays.
- Diet (e.g. ad libitum): CTI diet, Special Diets Services Ltd., Essex, UK.
- Water (e.g. ad libitum): yes

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-24
- Humidity (%): 44-70
- Air changes (per hr): 12
- Photoperiod (hrs dark / hrs light):12/12

IN-LIFE DATES: From: 15 Sept - 16 Oct 1987.

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The experimental diets were prepared in 30 kg batches from premixes.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Chemical stability was observed at 300 ppm up to at least 32 days. This interval was in excess of the maximum period of use of the first batch of diet (21 days from preparation). The achieved concentration was within 8% of target and the doses received by the test groups were approximately 28, 170 and 1080 mg/kg bw/day.

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: not reported
- Length of cohabitation: overnight
- Proof of pregnancy: sperm in vaginal smear referred to as day 1 of pregnancy

Successfully mated females were delivered to the experimental unit.
A total of 96 mated females was supplied over a two week period.

Duration of treatment / exposure:

days 1-22 of gestation.

Frequency of treatment:

Continuous feeding

Duration of test:

22 days

No. of animals per sex per dose:

24

Control animals:

yes, plain diet

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: on arrival and daily

BODY WEIGHT: Yes
- Time schedule for examinations: daily during days 1-22 of gestation

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 22
- Organs examined: uterus, ovaries, liver, spleen, kidney, stomach, rectum, abdominal cavity, pelvic cavity,

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes, in each ovary.
- Number of implantations: Yes
- Number of early resorptions: Yes (early intra-uterine deaths)
- Number of late resorptions: Yes (late intra-uterine deaths)
- Other: Each foetus was weighed and individually identified within the litter by means of a cardboard tag. After weighing the foetuses were killed with an intra-cardiac injection of pentobarbitone.

Fetal examinations:

- External examinations and cleft palate: Yes, each foetus
- Soft tissue examinations: Yes, all
- Skeletal examinations: Yes, all
- Head examinations: Yes, the head of each foetus was cut along the fronto-parietal suture line and the brain was examined for macroscopic abnormalities.

Statistics:

Analysis of variance, Student's t-test, Fisher's Exact Test

Indices:

- Pre-implantation loss (No. of corpora lutea / No. of implantations)
- Post implantation loss (No. of implantations / No. of live foetuses)

Historical control data:

Yes, data on variants and frequency of occurence in rats of this strain were given.
Defects like bipartite 5th sternebrae, slightly dilated ureters and kinked ureters were seen in historical controls of this strain.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
At 12000 ppm a small but statistically significant reduction in maternal bodyweight gain was observed.
There was also a small but statistically significant reduction in food consumption at this dose level from days 2-18 inclusive of gestation.
There was no evidence of maternal toxicity at 300 or 1800 ppm.

Dose descriptor:

NOAEL

Effect level:

ca. 170 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

LOAEL

Effect level:

ca. 1 080 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

>= 1 080 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Dose descriptor:

NOEL

Effect level:

ca. 28 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Dose descriptor:

LOEL

Effect level:

ca. 170 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes. Remark: (non-adverse)

Details on embryotoxic / teratogenic effects:
There was no effect at any dose on foetal weight, litter weight, gravid uterus weight, numbers of intra-uterine deaths or numbers of external abnormalities. At 12000 ppm there was a minimal increase of pre-implantation loss with an associated decrease in litter size.
Six major abnormalities (in five foetuses) were seen in the treated groups and eight in the control group (of which seven consisted of multiple minor skull defects in one litter). There was no evidence that the type or distribution of these abnormalities was related to treatment with the test substance.
Overall, minor skeletal defects were increased in a dose-related manner at 1800 and 12000 ppm of the test substance, while skeletal variants (as a percentage of foetuses affected) were increased at the top dose only. These findings indicated slightly poorer ossification at dose levels of 1800 and 12000 ppm, which were considered to be the result of slight fetotoxicity. However, the slightly poorer ossification is not considered as adverse effect.

Abnormalities:

not specified

Developmental effects observed:

not specified

Table 1: Foetal defects and variants - Intergroup comparison of foetal defects and variants

	Dietary conc. of DEHA (ppm)
	0	300	1800	12000
No. of litters examined	24	23	24	23
External and visceral defects
No. of foetuses examined	282	263	278	243
No. of foetuses showing major defects	1	2	0	2
No. of foetuses showing minor defects only	7	8	9	3
Variants
No. of foetuses showing variants	69	69	81	78*
Skeletal defects
No. of foetuses examined	282	263	278	243
No. of foetuses showing major defects	7	0	1	1
No. of foetuses showing minor defects only	70	78	97**	120**
Variants
No. of foetuses showing variants	270	257	268	243**

 

Table 2: Summary of the type and incidence of major defects

	Dietary conc. of DEHA (ppm)
	0	300	1800	12000
External/Visceral
Situs inversus totalis	0	0	0	1
Left adrenal, kidney and ureter absent	1	0	0	0
Cysts attached to liver	0	1	0	0
Small right kidney	0	1	0	0
Umbilical hernia	0	0	0	1
Skeletal
Skull: Multiple minor defects	7	0	0	0
3^rdand 7^thribs (left) not ossified0	0	0	0	1
1^strib (right) partially ossified	0	0	1	0

 There was no evidence that the test substance is teratogenic to the rat at any of the dose levels tested (up to 12000 ppm -approximately 1000 mg/kg/day). Administration of 12000 ppm DEHA resulted in slight maternal toxicity and slight foetotoxicity.

At 1800 ppm, there was no evidence of maternal toxicity although minimal foetotoxicity was observed. A dietary level of 300 ppm DEHA was a clear no-effect level for embryonic development. 

Conclusions:

CLP: not classified

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Quality of whole database:

The available information comprises an adequate and reliable study (Klimisch score 2 due to read-across) from a reference substance with similar structure and intrinsic properties. Read-across is justified based on common functional group(s), similar precursors/breakdown products and similarities in PC/ECO/TOX properties. The selected study is thus sufficient to fulfil the standard information requirements set out in Annex VIII-IX, 8.7, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no study available

Additional information

Justification for grouping of substances and read-across

There are only limited data available on toxicity to reproduction of Diisooctadecyl malate (CAS 67763-18-2). In order to fulfil the standard information requirements set out in Annex VIII, 8.7, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from structurally related substances was conducted. In accordance with Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met.” In particular for human toxicity, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across). Having regard to the general rules for grouping of substances and read-across approach laid down in Annex XI, Item 1.5, of Regulation (EC) No 1907/2006 whereby substances may be predicted as similar provided that their physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity.

Overview of toxicity to reproduction

CAS	Chemical name	Molecular weight [g/mol]	Toxicity to reproduction	Developmental toxicity / teratogenicity
67763-18-2 (a)	Diisooctadecyl malate	639.06	--	RA: CAS 103-23-1
103-23-1 (b)	Bis(2-ethylhexyl) adipate	370.57	--	Experimental result: NOAEL (maternal) = 170 mg/kg bw/day NOAEL (developmental)≥1080 mg/kg bw/day

(a) The substance subject to registration is indicated in bold font.

(b) Reference (read-across) substances are indicated in normal font. Lack of data for a given endpoint is indicated by “--“.

The above mentioned substances are considered to be similar on the basis of the structural similar properties and/or activities. The available endpoint information is used to predict the same endpoints for Diisooctadecyl malate (CAS 67763-18-2). A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Discussion

Developmental toxicity/teratogenicity

No data on developmental/teratogenicity is available with Diisooctadecyl malate (CAS 67763-18-2). Therefore, read across from the structurally analogue substance Bis(2-ethylhexyl) adipate (CAS103-23-1)was applied.

CAS 103-23 -1

A reliable key developmental toxicity study performed according to OECD TG 414 with Bis(2-ethylhexyl) adipate (CAS103-23-1) is available (Hodge, 1988). Groups of 24 female mated Alpk:APfSD (Wistar derived) rats received the test substance at dietary concentrations of 300, 1800 and 12000 ppm, corresponding to dose levels of 28, 170 and 1080 mg/kg bw/day during Days 1 to 22 of gestation. A further group of 24 mated females received the plain diet and served as controls. On Day 22 of gestation, dams were sacrificed and maternal as well as foetal examinations were performed. Maternal toxicity occurred at 12000 ppm and involved a small, but statistically significant decrease in body weight gain compared to controls. This effect was accompanied by slight, statistically significant reduction in food consumption between Days 2 to 18 of gestation. No treatment-related clinical signs were observed during the study and no adverse findings were noted at macroscopic examination of dams. There was no effect at any dose level on fetal weight, litter weight, gravid uterus weight, numbers of intra-uterine deaths or numbers of external abnormalities. At 12000 ppm, a minimal increase of pre-implantation loss associated with a decrease in litter size was observed. Six major abnormalities (in five fetuses) were seen in the treated groups and eight in the control group (of which seven consisted of multiple minor skull defects in one litter). There was no evidence that the type or distribution of these abnormalities was related to test substance treatment. Overall, minor skeletal defects were increased in a dose-related manner at 1800 and 12000 ppm, while skeletal variants (as a percentage of fetuses affected) were increased at the 12000 ppm only. These findings indicated slightly poorer ossification at dose levels of 1800 and 12000 ppm, which were considered to be the result of slight fetotoxicity. However, the slightly poorer ossification is not considered as adverse effect. There was no evidence at any dose level, that the test substance was teratogenic in rats. Based on the results of the study, the NOAEL for maternal and developmental toxicity was considered to be 1800 ppm (170 mg/kg bw/day) and ≥12000 ppm (≥1080 mg/kg bw/day), respectively.

Justification for selection of Effect on developmental toxicity: via oral route:
Hazard assessment is conducted by means of read-across from a structural analogue. The selected study is the most adequate and reliable study based on the identified similarities in structure and intrinsic properties between source and target substance and overall assessment of quality, duration and dose.

Justification for classification or non-classification

According to Article 13 of Regulation (EC) No. 1907/2006 "General Requirements for Generation of Information on Intrinsic Properties of substances", information on intrinsic properties of substances may be generated by means other than tests e.g. from information from structurally related substances (grouping or read-across), provided that conditions set out in Annex XI are met. Annex XI, "General rules for adaptation of this standard testing regime set out in Annexes VII to X” states that “substances whose physicochemical, toxicological and ecotoxicological properties are likely to be similar or follow a regular pattern as a result of structural similarity may be considered as a group, or ‘category’ of substances. This avoids the need to test every substance for every endpoint". Since the analogue concept is applied to Diisooctadecyl malate (CAS 67763-18-2), data will be generated from information on reference source substance(s) to avoid unnecessary animal testing. Additionally, once the analogue read-across concept is applied, substances will be classified and labelled on this basis.

Therefore, based on the analogue read-across approach, the available data on toxicity to reproduction do not meet the classification criteria according to Regulation (EC) 1272/2008, and are therefore conclusive but not sufficient for classification.