2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate

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

Justification for read-across

There are no data on the reproduction toxicity of 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate (CAS 68258-72-0). The assessment was therefore based on studies conducted with analogue substances as part of a read-across approach, which is in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5. For each specific endpoint the source substance(s) structurally closest to the target substance is/are chosen for read-across, with due regard to the requirements of adequacy and reliability of the available data. Structural similarities and similarities in properties and/or activities of the source and target substance are the basis of read-across. A detailed justification for the read-across approach is provided in the technical dossier (see IUCLID Section 13).

Toxicity to reproduction

A screening study for reproductive/developmental toxicity is not available. Referring to Column 2 of Annex VIII, Section 8.7.1, Regulation (EC) No 1907/2006 suitable data is included to cover the toxicity to reproduction endpoint. A pre-natal developmental toxicity study performed with a source substance according to OECD 414 is available via read-across (Trimmer, 1995). No treatment-related effects were observed on any of the assessed reproductive and developmental parameters. Two 90-day oral repeated dose toxicity studies, performed with two source substances, are available (McRae, 2004; Müller, 1998). In these studies no treatment-related effects were observed on the weight and histopathological structure of reproductive organ and tissues.

Justification for selection of Effect on fertility via oral route:
No study required since an adequate and reliable pre-natal dvelopmental toxicity study (OECD 414) is available and no adverse effects were seen on reproductive organs and tissues in a 90-day repeated dose toxicity study (OECD408).

Effects on developmental toxicity

Description of key information

Oral: OECD 414, rat, NOAEL development ≥ 1000 mg/kg bw/day
Oral: OECD 414, rat , NOAEL systemic ≥ 1000 mg/kg bw/day

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions; lack of data on test substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

- lack of data on test substance

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

other: Crl:CD BR VAF/Plus

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Stone Ridge, NY, USA
- Age at study initiation: approximately 9 - 10 weeks
- Weight at study initiation: 200 - 274 g (female)
- Housing: The animals were housed in suspended stainless steel and wire mesh cages with absorbent paper below the cages. The females were housed separately during the study period except during mating.
- Diet: Purina Certified Rodent Chow No. 5002, ad libitum
- Water: tap water, ad libitum
- Acclimation period: 13 d

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.0 - 24.4
- Humidity (%): 40 - 70
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES:
From: 03 Oct 1994
To: 08 Nov 1994

Route of administration:

oral: gavage

Vehicle:

other: polyethylene glycol (PEG 400)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: The undiluted test substance was thoroughly mixed in vehicle prior to dispensing. The dosing solutions were prepared weekly.

VEHICLE
- Lot/batch no. (if required): 122H1109
- Physical state: colorless liquid

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analysis for homogenity of the test substance dilutions were performed on the lowest and the highest concentrations expected during the course of the study. The relative standard deviation ranged from 0.72 to 3.19%. Concentrations were analysed in the first and the third dosing mixture preparation. The analytical results for all test solutions were within 7% of the nominal concentrations for weeks 1 and 3.

Details on mating procedure:

- Impregnation procedure: cohoused
- M/F ratio per cage: 1/1
- Verification of same strain and source of both sexes: yes
- Proof of pregnancy: vaginal plug and/or sperm in vaginal smear referred to as day 0 of pregnancy
After confirmation of pregnancy, each mated female was returned to its cage and new females were placed into the males' cages until a required number of pregnant females was obtained.

Duration of treatment / exposure:

gestation days (GD) 6 - 15

Frequency of treatment:

daily, 7 d/week

Duration of test:

21 d (GD 0 - 21)

No. of animals per sex per dose:

25 females per dose, 50 males in total

Control animals:

yes, concurrent vehicle

Details on study design:

- Rationale for animal assignment: Mated females were assigned to dose groups in the order of mating. Accordingly, the first confirmed mated female was assigned to Group 1, the next to Group 2 and so on until all mated animals for a given day were assigned to dose groups. On subsequent days, the next group in sequence was filled by the first confirmed mated female on that day and so on. Assignments were made until all groups were filled with confirmed mated females.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily during the treatment period and once daily at all other times during the study period

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: prior to selection and daily during gestation

BODY WEIGHT: Yes
- Time schedule for examinations: prior to selection and on GD 0, 6, 9, 12, 15, 18 and 21

FOOD CONSUMPTION: Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Time schedule for examinations: concurrently with body weight examinations

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on GD 21
- all females were examined by gross necropsy

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
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

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

Statistics:

Bartlett's Test was performed to determine if the dose groups had equal variance (1% level of significance). If equal, the testing was done using parametric methods, otherwise nonparametric techniques were used. Parametric procedures: a standard one way ANOVA (F distribution) was used. If significant differences among the means were indicated, Dunnett's Test was used to determine which treatment groups differed significantly from control. In addition to the ANOVA, a standard regression analysis for linear response in the dose groups was performed that also tested for linear lack of fit in the model. Nonparametric procedures: the test of equality of means was performed using the Kruskal-Wallis Test. If significant differences among the means were indicated, Dunn's Summed Rank Test was used to determine which treatment groups differed significantly from the control. In addition, Jonckheere's Test for monotonic trend in the dose response was performed. All tests were conducted at the 5% and 1% level of significance.
Fetal weight was analyzed by a standard nested analysis of covariance (fetuses nested within dams and dams nested within doses and litter size (both sexes combined)). If differences in groups were identified, the Least Significant Difference technique was used to determine which groups differed from the control group. Male and female fetuses were tested separately (the covariate was combined sexes in each analysis). Fetal malformation and variation incidence data were analyzed for statistical significance as follows: a standard chi-square analysis was performed to determine if the proportions of incidences differ between the groups tested. If any one cell had an expected value less than 5, this step was not reported. Next, each treatment group was compared to the control group using a 2x2 Fisher Exact Test. Thirdly, Armitage's test for linear trend in the dosage groups was performed. All tests were reported at the 5% or 1% level of significance.

Indices:

Preimplantation loss = (no. of Corpora Lutea - no. of Implantation Sites) / no. of Corpora Lutea * 100

Postimplantation loss = (no. of Implantation Sites - no. of live foetuses) / no. of Implantation Sites * 100

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
Mortality:
No treatment-related mortality occurred. On GD 7, one female of the 500 mg/kg bw/d group was found dead. At necropsy, discolored and consolidated lungs were the only findings. The death of this female was probably a result of an accidental gavage error.

Clinical signs:
No treatment-related clinical signs were observed during the study period. The most frequently observation was soft stool, that occurred in treated and control animals and was therefore considered as a response to the vehicle rather than to the test substance. Other findings were scabs, little sign of stool, rales and alopecia in one or more groups. One female of the high dose group had a subcutis mass in the cervical area on GD 21. In summary, these clinical findings were considered to be incidental and unrelated to treatment with the test substance.

Body weight:
Treatment with the test substance had no statistically significant effect on mean body weight and mean body weight change at any interval.

Food consumption:
There were no statistically significant differences in mean food consumption between treated and control animals at any interval.

Post-mortem examinations:
There were no necropsy findings that were considered to be treatment-related. One high dose female had a subcutaneous mass in the cervical area and one control and one high dose female had dilated renal pelvis. In summary, these necropsy findings were considered to be incidental and unrelated to treatment.

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: NOAEL is corresponding to the highest dose tested

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Fetal body weight:
There were no statistically significant differences between treated and control mean fetal body weights of either sex (see Table 1).

Implantation data:
There were no statistically significant differences in the mean live fetuses, mean live male or female fetuses, mean resorptions, mean implantation sites, mean corpora lutea, mean total dead fetuses, mean fetuses per implantation sites, mean dead fetuses per implantation sites, mean resorptions per implantation sites, % pre-implantation loss, % post-implantation loss, mean malformed fetuses, mean fetuses with variations, or mean affected (resorptions + dead + malformed fetuses per litter) fetuses between treated and control groups. (see Table 1)

Fetal observations:
No biologically or statistically significant differences in total or individual variations or malformations were observed between the litters of test substance groups and control group (see Table 2). In the control, 100, 500 and 1000 mg/kg bw/d group, 5, 2, 6 and 1 fetuses, respectively, were stunted.
External observations regarded as malformations were found in one fetus of the 100 mg/kg bw/d group (agnathia, astomia, low set ears, anophthalmia) and single findings of cleft palate, syndactyly and kinked tail in three foetuses of separate litters of the 500 mg/kg bw/d group. External variations were not observed in any group.
Visceral observations regarded as malformations were limited to single occurrences of anophthalmia in one foetus each of the low and mid dose group, cleft palate and dilated brain ventricles in the 100 mg/kg bw/d group and two occurrences of folded retina in the control group. Visceral variations included a single or low incidence of dilated renal pelves, distended ureters and/or convoluted ureter.
Skeletal observations regarded as malformations were limited to multiple skull bones malformed in one foetus of the 100 mg/kg bw/d group, short pubis in one foetus of the 1000 mg/kg bw/d group and one less presacral vertebrae in one foetus of the control, two foetuses in the low dose and one foetus in the high dose groups. Skeletal variations were observed throughout the groups and consisted primarily of hypoplastic, misshapen or unossified stemebrae, hypoplastic skull bones or pubis and rudimentary or misshapen ribs.
In summary and without a clear pattern of response, all malformations were considered incidental and not to be treatment-related. Statistically significant differences in incidences of variations were limited to a decrease in hypoplastic skull bones of the mid dose group and a decrease in unossified stemebrae of the high dose group compared with controls. All variations were of no biological importance.

Skeletal ossification:
There were no statistically significant differences in mean ossification sites between treated and control groups.

Dose descriptor:

NOAEC

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse effects observed

Abnormalities:

not specified

Developmental effects observed:

not specified

Table 1: Litter data and fetal body weight

 

	Control	dose groups [mg/kg bw/day]
		100	500	1000
No. of dams/litters examined	25	21	23	25
Mean no. of Corpora Lutea	16.8	16.8	17.7	16.8
	± 2.28	± 2.50	± 3.50	± 1.82
	n=25	n=20	n=23	n=25
Mean no. of Implantation Sites	15.76	15.9	16.09	15.52
	± 2.24	± 2.62	± 2.25	± 2.49
	n=25	n=21	n=23	n=25
Mean no. of resorptions	0.88	0.81	0.91	0.56
	± 1.05	± 1.29	± 1.12	± 0.82
	n=25	n=21	n=23	n=25
Pre-implantation loss [%]	5.7	6.7	8	7.7
	± 8.1	± 8.2	± 8.2	± 12.9
	n=25	n=20	n=23	n=25
Post-implantation loss per litter [%]	5.4	4.9	6	4.4
	± 6.4	± 7.7	± 7.3	± 6.4
	n=25	n=21	n=23	n=25
Mean no. of live fetuses	14.88	15.1	15.13	14.88
	± 2.19	± 2.64	± 2.46	± 2.64
	n=25	n=21	n=23	n=25
Mean no. of dead fetuses	0	0	0.04	0.08
			± 0.21	± 0.28
	n=25	n=21	n=23	n=25
Mean no. of female fetuses	7.72	7.48	8.04	7.8
	± 2.28	± 3.11	± 2.29	± 1.78
	n=25	n=21	n=23	n=25
Mean no. of male fetuses	7.16	7.62	7.09	7.08
	± 1.93	± 2.25	± 2.09	± 2.58
	n=25	n=21	n=23	n=25
Mean body weight (female fetuses) (g)	5.04	5.05	5.06	5.2
	± 0.44	± 0.32	± 0.46	± 0.37
	n=188	n=157	n=185	n=195
Mean body weight (male fetuses) (g)	5.33	5.27	5.39	5.44
	± 0.52	± 0.39	± 0.38	± 0.38
	n=175	n=160	n=163	n=177

Table 2: Fetal variations and malformations

 

	Control	dose groups [mg/kg bw/day]
		100	500	1000
No. of fetuses with external variations	0	0	0	0
	n=372	n=317	n=347	n=358
No. of fetuses with external malformations	0	1	3	0
	n=372	n=317	n=347	n=358
No. of fetuses with visceral or head variations	0	0	1	2
	n=187	n=161	n=173	n=186/187*
No. of fetuses with visceral or head malformations	2	2	1	0
	n=187	n=161	n=173	n=186/187*
No. of fetuses with skeletal variations	45	39	29	35
	n=185	n=156	n=176	n=185
No. of fetuses with skeletal malformations	1	3	0	2
	n=185	n=156	n=176	n=185

  

*186 visceral examinations performed, 187 head examinations performed

Conclusions:

The test substance was not considered embryotoxic under the conditions of this study. Accordingly, the maternal and developmental NOAELs were established at 1000 mg/kg bw/d under the conditions of this study. The results indicate that test substance was not a selective developmental toxicant and was not embryotoxic or teratogenic under the conditions of this study.

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 precursors and breakdown products of hydrolysis and consistent trends in environmental fate, ecotoxicological and toxicological profile (refer to the endpoint discussion for further details).
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 read-across

Data on developmental toxicity of of 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate (CAS 68258-72-0) are not available. The assessment was therefore based on studies conducted with analogue substances as part of a read-across approach, which is in accordance with Regulation (EC) No. 1907/2006, Annex XI, 1.5. For each specific endpoint the source substance(s) structurally closest to the target substance is/are chosen for read-across, with due regard to the requirements of adequacy and reliability of the available data. Structural similarities and similarities in properties and/or activities of the source and target substance are the basis of read-across. A detailed justification for the analogue read-across approach is provided in the technical dossier (see IUCLID Section 13).

Developmental toxicity/teratogenicity

CAS 189200-42-8

The potential of fatty acids C8-10, mixed esters with dipentaerythritol, isooctanoic acid, pentaerythritol and tripentaerythritol to cause developmental toxicity was assessed in a prenatal developmental toxicity study performed according to OECD guideline 414 and under GLP conditions (Trimmer, 1995). 25 pregnant dams/dose were administered 100, 500 and 1000 mg/kg bw/day by gavage during gestation day 6 to 15. On day 21 of gestation the animals were euthanized and examined. No treatment-related systemic effects were observed in the P-females. One female in the 500 mg/kg bw/day group died, most likely due to a dosing error. No treatment-related effects on the dam reproductive parameters (number of corpora lutea, implantation sites, pre-implantation loss, resorptions) were observed. There were no significant differences between the control and treatment pups in the developmental parameters (post-implantation loss, body weight, sex ratio, viability). The incidence of malformations and variations in the offspring was comparable between the control and treatment groups. The NOAEL for developmental toxicity and teratogenicity was set at ≥ 1000 mg/kg bw/day.

Overall conclusion for developmental toxicity/teratogenicity

There are no available studies on the developmental toxicity and teratogenicity of 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate. Therefore analogue read-across from a source substance was applied. No hazard to development was identified. Based on the available data and following the analogue approach, the target substance 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate is considered to be not toxic to development.

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 the source and target substance and overall assessment of quality, duration and dose (refer to the endpoint discussion for further details).

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 2,2-bis(hydroxymethyl)propane-1,3-diyl didocosanoate (CAS 68258-72-0), data will be generated from data for 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.

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

An OECD Guideline 414 study will not provide evidence for definite claims of no fertility effects. However, since no adverse effects on reproduction and development was noted up to and including the limit dose of 1000 mg/kg bw/day in the available study, the conclusion of no classification (conclusive but not sufficient for classification) is considered to be justified.