Fatty acids, C18-(unsaturated) dimers and their monoesters and diesters with 2-ethylhexanol

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

No other studies are available.

Link to relevant study records

Reference

Endpoint:

screening for reproductive / developmental 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:

2003

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Robust summary of study published in official document submitted to US EPA. There the study was classified as Klimisch 1a. The study was GLP compliant and performed according to OECD guideline 421. As the robust study summary is taken from a secondary source the reliability was downgraded.

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Four groups of 10 male and 10 female Sprague-Dawley rats

Route of administration:

oral: feed

Duration of treatment / exposure:

4 weeks

Frequency of treatment:

Males were treated for at least 4 weeks overall, starting from 2 weeks prior to mating until termination; females were treated for 2 weeks prior to mating, then through mating until termination after Day 4 of lactation.

Remarks:

Doses / Concentrations:
200 ppm
Basis:

Remarks:

Doses / Concentrations:
2,000 ppm (appr. 180 mg/kg/day)
Basis:

Remarks:

Doses / Concentrations:
20,000 ppm (appr. 1,858 mg/kg/day)
Basis:

No. of animals per sex per dose:

10

Control animals:

yes

Parental animals: Observations and examinations:

The animals were monitored for clinical signs, body weight, food consumption, mating and litter performance.
All animals were submitted for necropsy, which included weighing male reproductive organs. Histopathology was conducted on the epididymides and testes of all control and high dose males and on the ovaries of all control and high dose females.

Paternal toxicity was exhibited at 20000 ppm as a slight decrease in weight gain and an increase in piloerection. There were no obvious maternal effects at this level. There were no obvious parental effects at 200 or 2,000 ppm, nor were there any effects of treatment on the reproductive parameters at any dose level applied. The testes and epididymides weights were essentially similar in all groups.
The mean number of implants per pregnancy was higher in all the treated groups compared to controls. However, historical data shows that the findings in the treated groups were within background ranges for animals of this age and strain. Rather, it was considered most likely that the control value was at the lower end of the background range. There were no obvious effects of treatment on litter size, litter survival, or pup weights at any dose level and no abnormalities noted among pups.

Dose descriptor:

NOEL

Effect level:

180 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: slight decrease in weight gain and an increase in piloerection

Dose descriptor:

NOEL

Effect level:

1 858 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: reproductive parameters

Remarks on result:

not measured/tested

Reproductive effects observed:

not specified

Conclusions:

Under the conditions of this study, the parental No Observed Effect Level (NOEL) of fatty acid, C18-unsaturated dimers in rats was considered to be 2,000 ppm (approximately 180 mg/kg/day) and for reproductive parameters the NOEL was considered to be 20,000 ppm (approximately 1,858 mg/kg/day).

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

180 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

The study was GLP compliant and was performed according to OECD guideline 421.

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

The parental NOEL for fatty acids, C18-unsaturated dimers in rats was considered to be 2,000 ppm (approximately 180 mg/kg/day) and for reproductive parameters the NOEL was considered to be 20,000 ppm (approximately 1,858 mg/kg/day).

A supporting long-term and multigenerational study with rats feed with medium chain triclycerides (MCT) (75% octanoic acid, 25% decanoic acid) showed normal reproduction, as indicated by litter size and number. After weaning, growth of the rats fed MCT was similar to animals on the oleo oil diet. No specific toxic effects in mice were observed.

No studies on the toxicity to reproduction of 400160 are available. However studies on the developmental toxicity are available for 2-ethylhexanol applied orally to mice and dermally to rats. These studies were used as read-across to structural analogues. In accordance with REACH Annex VIII, column 2 (8.7.1) a screening test for reproductive/developmental toxicity does not need to be conducted if a pre-natal developmental toxicity study (Annex IX, 8.7.2) or a two-generation reproductive toxicity study (Annex IX, section 8.7.3) is available.

Short description of key information:
No effects on reproductive parameters for fatty acids, C18-unsaturated dimers (main raw material of 400160) and medium-chain triglycerides were observed in rats.
No experimental study on toxicity to reproduction of 400160 is available. However experimental studies on developmental toxicity/ teratogenicity of 2-ethylhexanol can be used as read across based on similar structure.

Effects on developmental toxicity

Description of key information

Information on developmental toxicity is available for 2-ethylhexanol, a raw material of 400160. The NOAEL of dermal application was 840 and ≥ 2520 mg/kg/day for maternal and developmental toxicity. For oral application the NOAEL for maternal and developmental toxicity was each 191 mg/kg bw/day. A lower NOAEL of 130 mg/kg/day was determined in another oral study with 2-ethylhexanol in rats. This study showed significant maternal toxicity at higher doses and a lower number of animals were used as recommended in the guideline.
A supporting feeding study of cuphea oil to three generations showed no effects on reproduction in mice.

Link to relevant study records

Reference

Reference 1

Endpoint:

developmental toxicity

Type of information:

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

Adequacy of study:

key study

Study period:

1990-05-18 to 1990-08-22

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP - Guideline study, tested with the source substance 2-EH (CAS No. 104-76-7)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

not specified

Limit test:

no

Species:

mouse

Strain:

CD-1

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Raleigh, NC
- Weight at study initiation: 23.52-31.59 g
- Housing: Plug-positive females were individually housed in solid-bottom polycarbonate cages with stainless steel wire lids (Laboratory Products, Rochelle Park, NJ) and Ab-Sorb-Dri® cage litter (Laboratory Products, Garfield, NJ
- Diet (e.g. ad libitum): Ground Purina Certified Rodent ChoW® (#5002) available ad libitum throughout gestation
- Water (e.g. ad libitum): deionized/filtered water were available ad libitum throughout gestation
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22.2
- Humidity (%): 48
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

oral: feed

Vehicle:

other: food grade modified corn starch microcapsules

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:

DIET PREPARATION
- Rate of preparation of diet (frequency): Fresh supplies of dosed feed were obtained from refrigerated stock on the mornings of gestational day 0, 3, 6, 9, 12 and 15

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analysis by gas chromatography prior to use verified the formulations to be within 99-108% of the theoretical concentrations. 2-ethylhexanol/feed mixes were determined to be stable throughout the period of use for each study replicate.

Details on mating procedure:

- Impregnation procedure: cohoused
- M/F ratio per cage:1/1
- Length of cohabitation: overnight
- Proof of pregnancy: vaginal plug referred to as day 0 of pregnancy
- Verification of same strain and source of both sexes: yes

Duration of treatment / exposure:

continuously exposure to 2-ethylhexanol (0, 0.009, 0.03, or 0.09%) microencapsulated in the feed from gestational day 0-17

Frequency of treatment:

continuously ad libitum feed

Duration of test:

sacrifice at gestational day 17

Remarks:

Doses / Concentrations:
0.009, 0.03 and 0.09%
Basis:
nominal in diet

Remarks:

Doses / Concentrations:
0, 17, 59 and 191 mg/kg bw/d
Basis:
other: calculated consumption, based on gestational food consumption

No. of animals per sex per dose:

28

Control animals:

yes, plain diet

Details on study design:

- Dose selection rationale: di-(2-ethylhexyl)phthalate (DEHP9 was previously evaluated for potential developmental toxicity in timed-pregnant Swiss (CD-I) mice exposed via the diet throughout gestation (gestational day 0 to 17) (Tyl et al. 1988). An average dose of 44 mg/kg/day (0.025% DEHP in feed) was the maternal and embryo/fetal NOAEL. An increased incidence of malformations was observed at 91 mg/kg/day (0.05% DEHP in feed) in the absence of other indications of maternal and embryo/fetal toxicity. At 191 and 292 mg/kg/day (0.10% and 0.15% DEHP in feed), maternal toxicity (reduced weight gain during treatment and increased relative liver weight) was observed, as well as decreased fetal weight and an increased incidence of prenatal mortality and fetal malformations. Based upon these findings, additional studies were designed to characterize the developmental toxicity of DEHP's principal metabolites (MEHP and 2-ethylhexanol) at approximately equimolar doses and under comparable experimental conditions as those from the study of DEHP in mice (Tyl et al., 1988). Accordingly, the concentrations of MEHP in feed included 0% (control), 0.017%, 0.035%, 0.070%, and 0.140%, with the average daily intake of 0, 35, 73, 134, and 269 MEHP mg/kg/day, respectively (NTP, 1990), approximately equivalent on a molar basis to the dose levels of DEHP used by Tyl et al. (1988). The target concentrations of 2-EH in feed employed for this study included 0.00% (control), 0.009%, 0.030%, and 0.090%. The expected average daily intake of 2-EH at the proposed dietary concentrations were 0, 15, 52.5, and 157.5 mg/kg/day, respectively. The actual intake was 0, 17, 59 and 191 mg/kg/day. Therefore, the target dietary dose levels of 2-EH employed for this study were intended to encompass the range of intakes obtained with DEHP.

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily from gestational day 0-17

BODY WEIGHT: Yes
- Time schedule for examinations: on gestational days 0, 3, 6, 9, 12, 15, and 17

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Time schedule for examinations: on gestational days 0, 3, 6, 9, 12, 15, and 17

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestational day 17
- Organs examined: The maternal body, liver, and intact uterus were weighed and ovarian corpora lutea were counted

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:

- Body weight: Yes
- 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:

General Linear Models (GLM) procedures were applied for the analyses of variance (ANOVA) of maternal and fetal parameters (SAS Institute, 1989a,b; 1990 a,b,c). Prior to GLM analysis, an arcsine-square root transformation was performed on all litter-derived percentage data (Snedecor and Cochran, 1967) and Bartlett's test for homogeneity of variance was performed on all data to be analyzed by ANOVA (Winer, 1962). GLM analysis determined the significance of dose-response relationships and the significance of dose effects, replicate effects and dose x replicate interactions. Dose x replicate interactions were nonsignificant (p>0.05) for all maternal and embryo/fetal endpoints analyzed by ANOVA, thus indicating that the results were consistent across replicates. When ANOVA revealed a significant (p<0.05) dose effect, Dunnett's Multiple Comparison Test (Dunnett, 1955; 1964) compared each 2-ethylhexanol-exposed group to the control group. One-tailed tests were used for all pairwise comparisons except maternal body and organ weights and fetal body weight .
Nominal scale measures were analyzed by a χ² test for independence and by a test for linear trend on proportions. When a χ² test showed significant group differences, a one-tailed Fisher's exact probability test was used for pairwise comparisons of each 2-ethylhexanol group with the control group.

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
No females died, delivered early or were removed from the study. Pregnancy rates were high and equivalent across all groups (93-96%); maternal weight change for the gestational (and treatment) period, gestational day 0-17, was unaffected, as was weight change corrected for gravid uterine weight; maternal organ weights and food consumption were also unaffected; Treatment related clinical signs of toxicity were limited to hyperactivity observed in one dam on gestational day 6, 9 and 12 at 0.090% and in one dam on gestational day 6 at 0.030%

Dose descriptor:

NOAEL

Effect level:

191 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

191 mg/kg bw/day

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:
There were no effects of exposure on the number of ovarian corpora lutea, or of uterine implantation sites (resorptions, dead fetuses or live fetuses) per litter. Live litter size and fetal body weight per litter (all fetuses, males or females) were equivalent across all groups.
There were also no effects of treatment on the incidence of malformations (external, visceral, skeletal or total) or variations, whether expressed as number or percentage of fetuses per litter or of litters with one or more affected fetuses. Examination of individual fetal findings also indicated no specific malformations or variations with a dose-related incidence.

Remarks on result:

not measured/tested

Abnormalities:

not specified

Developmental effects observed:

not specified

Conclusions:

2-ethylhexanol administered in the diet during gestation (gestational day 0-17) in CD1 mice at concentrations of 0, 0.13, 0.46, and 1.49 mmol/kg (corresponding to 0, 17, 59, and 191 mg/kg/day) resulted in no maternal or developmental toxicity.
In conclusion, 2-ethylhexanol plays essentially no role in the expression of di-(2-ethylhexyl)phthalate (DEHP)-induced maternal and developmental toxicity.

Executive summary:

Microencapsulated 2-ethylhexanol (2 -EH) (0%, 0.009%, 0.03%, or 0.09% in feed, corresponding to an average intake of 0, 17, 59, and 191 mg/kg/day) was provided on gestational days 0 to 17 ad libitum to timed-mated CO-1 mice (28/group). At sacrifice (gestational day 17), the number of ovarian corpora lutea and uterine implantation sites, including resorptions, and dead or live fetuses, were recorded. Live and dead fetuses were weighed. Live fetuses were sexed and examined for external, visceral and skeletal malformations and variations.

 

No dams died, delivered early or were removed from the study. Pregnancy rate was high and equivalent across all groups. There was no treatment-related maternal toxicity observed in this study.

 

There were no effects of exposure to dietary 2-EH on any gestational parameter. The number of corpora lutea, uterine implantation sites, pre- and postimplantation loss, sex ratio and live fetal body weight per litter were all equivalent across all groups. There were also no treatment-related changes in the incidence of individual, external, visceral, skeletal or total malformations or variations. In conclusion, there were no maternal or developmental toxic effects of 2-EH dietary exposure throughout gestation up to a concentration of 191 mg/kg/day. 

Reference 2

Endpoint:

developmental toxicity

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: Peer-reviewed publication, study according to OECD 414

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

not specified

Limit test:

no

Species:

rat

Strain:

Fischer 344

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories (Kingston, NY)
- Age on arrival: males: 70d; females: 63d
- Weight at study initiation: males: 175-200g; females: 130-150g
- Housing: pregnant females were housed singly in stainless steel wiremesh cages
- Diet ( ad libitum): ProLab Certified Ground Rodent Chow, Agway Inc., St. Mary´s, OH
- Water (ad libitum)
- Acclimation period: 2 weeks

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 68-73
- Humidity (%): 42-65 %
- Photoperiod (hrs dark / hrs light): 12/12

Route of administration:

dermal

Vehicle:

unchanged (no vehicle)

Details on exposure:

In the main study there were three treatment Ievels of 2-ethylhexanol, one of 2-ME (2-methoxyethanol), and a deionized water control, all applied dermally. Eight plug-positive females were used per treatment level in the range-finding study, and 25 per Ievel in the main study. Dermal test and reference compounds were applied undiluted; VPA (valproic acid; gavage reference compound) was given at a concentration of 200 mg/ml in corn oil. Treatment volumes were based on the animal body weight on gestational day 6 and were not adjusted for subsequent weight changes. Treatment days were gestational days 6 through 15.
For dermal treatment the appropriate volume of test or reference compound was dispensed from a 1.0 cm³ syringe on to the clipped and shaved dorsal skin (ca. 1.5 in²) between the scapulae, under a 2 in² gauze square. The application site was occluded with a Lycra-Spandex jacket with Velcro closures. A 1.5 x 2.5 inch polyethylene patch was attached at the application site under the jacket. After a 6-h exposure period the gauze and jacket were removed, and the application site was wiped gently with moist gauze and blotted dry. For oral gavage of VPA in com oil a dose volume of 2.0 mL was administered with an 18-gauge ball-end 3 inch needle attached to a 1.0 cm³ syringe.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The test substance 2-ethylhexanol had purity of 99.7% at the outset and at the end of an 84-day period by gas chromatographic analysis. It is thus stable over the treatment period. The dosing solution of the gavage reference compound (valproic acid) was stable and homogeneous at the 200 mg/ml Ievel over a 16-day period by gas chromatographic analysis.

Details on mating procedure:

After a 2-week quarantine period animals were mated 1:1. Gestational Day 0 was dated from the appearance of a copulatory plug.

Duration of treatment / exposure:

6 h

Frequency of treatment:

Treatment days were gestational days 6 through 15.

Duration of test:

gestational days 0-21

Remarks:

Doses / Concentrations:
0, 252, 840, 2520 mg/kg/d
Basis:
nominal conc.

No. of animals per sex per dose:

25

Control animals:

yes, sham-exposed

other: reference: 2-methoxyethanol

Maternal examinations:

CAGE SIDE OBSERVATIONS: No data

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: gestational days 0, 6, 9, 12, 15, and 21

FOOD CONSUMPTION: Yes
- Food consumption was measured for each 3-day interval from gestational days 0 through 21

WATER CONSUMPTION: No data

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestational day 21
- Organs examined: maternal uterine, liver weights and spleen, adrenals, kidneys, and thymus weight

OTHER: Skin irritation was measured before and after each 6-h treatment period, Irritation was scored according to FHSA standard (1985)

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
- Other: Ovaries, cervices, vaginas, and abdominal and thoracic cavities were examined grossly. Uteri were examined externally, removed, and dissected
The ovaries and uterine content was examined after termination: Yes / No / No data
Examinations included:
- Gravid uterus weight: Yes / No / No data
- Number of corpora lutea: Yes / No / No data
- Number of implantations: Yes / No / No data
- Number of early resorptions: Yes / No / No data
- Number of late resorptions: Yes / No / No data
- Other:

Fetal examinations:

- External examinations: Yes: [all per litter]
- Soft tissue examinations: Yes: [half per litter]
- Skeletal examinations: Yes: [half per litter]
- Head examinations: No data

Statistics:

The units of comparison were the pregnant rat or the litter. Quantitative continuous variables such as maternal body and organ weights were compared between 2-EH and sham control groups, between dermal reference and sham control groups, and between gavage reference and naive control groups. Levene's test for equal variances (Levene, 1960), ANOVA, and t-tests with Bonferroni probabilities for pairwise comparisons were used. The pooled t-test was used when Levene's test indicated homogeneous variances and ANOVA was significant. When Levene's test indicated heterogeneous variances, all groups were compared by an ANOVA for unequal variances (Brown and Forsythe, 1974) followed when necessary by the separate variance t-test. Nonparametric data following laparohysterectomy were evaluated using the Kruskal-Wallis test followed by the Mann-Whitney test when appropriate (Sokal and Rohif, 1969). Incidence data were compared using Fisher's exact test (Sokal and Rohif, 1969). The fiducial limit of 0.05 (two-tailed) was used as the criterion for significance.

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
No females died. In the main study two females in the sham control and two in the low dose group delivered early, and their data were omitted. Pregnancy rates at laparotomy for sham controls and for 2-ethylhexanol (2-EH)-treated animals were 75-92%. All females in 2-EH-treated groups had a 100% viability.
Clinical findings:
Body weight: Gestational weight changes (gestational days 0 through 21) not significantly different from sham controls. Weight gain was significantly reduced for gestational days 6 through 9 at 2520 mg/kg/day compared with the sham control.
Food consumption: There were no significant changes in food consumption at any treatment Ievel throughout gestation.
other: Treatment-related effects attributable to 2-EH at the application site were exfoliation, encrustation, and erythema. There was no edema. Exfoliation and encrustation occurred at all treatment Ievels of 2-EH; erythema occurred during treatment with 2-EH at levels of 840 mg/kg/day and above. Irritation (Draize scores) was essentially mild. There was no exacerbation by continued treatment. Erythema subsided immediately after the cessation of treatment.
Necropsy Findings:
Treatment-related findings were residual exfoliation and crusting at the application site at mid and high treatment Ievels. There were no differences from controls for any treatment Ievel of 2-EH, in maternal body weights, gravid uterine or corrected body weights, or in relative or absolute liver, thymus, spleen, adrenal and kidney weights.
Gestational Parameters:
2-EH was without adverse effect at any treatment Ievel, compared with controls, on total and nonviable implants, early or late resorptions, live or dead fetuses, fetal sex ratio, and mean fetal body weights per litter.

Dose descriptor:

NOAEL

Effect level:

840 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Dose descriptor:

NOAEL

Effect level:

>= 2 520 mg/kg bw/day (nominal)

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:
2-ethylhexanol (2-EH) was without adverse effect at any treatment Ievel, compared with controls, on total and nonviable implants, early or late resorptions, live or dead fetuses, fetal sex ratio, and mean fetal body weights per litter.
Fetal Malformations and Variations:
There were no external, visceral, or skeletal malformations and no increases in external, visceral, or skeletal variations associated with any treatment Ievel of 2-EH.

Dose descriptor:

NOAEL

Effect level:

2 520 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: teratogenicity

Abnormalities:

not specified

Developmental effects observed:

not specified

Conclusions:

No developmental toxicity by dermal route noted at and below dose levels producing maternal toxicity.

Executive summary:

The developmental toxicity of 2 -ethylexanol (2 -EH) following dermal absorption was examined in a OECD TG 414 rat study that was conducted under GLP. 2 -EH was applied to the skin of 25 females at 252, 840, and 2520 mg/kg bw/day under an occlusive dressing during gestational days 6 -15 for 6 hours per day.

2-EH is essentially without developmental or teratogenic effects in the presence of demonstrable maternal toxicity, when administered by dermal route to pregnant F344 rats on gestational days 6 through 15. Maternal toxicity was limited to reduced body weight gain at 1680 and 2520 mg/kg/day and to mild or moderate skin irritation at 840 and 2520 mg/kg/day. Both effects occurred during treatment and were transient or ameliorated after treatment ceased. There were no other clinical findings and no effects on selected organs at necropsy. There were no effects on gestational parameters and no significant differences from controls in the incidence of fetal malformations and variations.

Therefore, the NOAEL for maternal systemic toxicity was 840 mg/kg bw/day, based on the effects on body weight gain; the NOAEL for skin irritation was 252 mg/kg bw/day. The NOAEL for developmental toxicity and teratogenicity was 2520 mg/kg bw/day.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

191 mg/kg bw/day

Study duration:

subchronic

Species:

mouse

Quality of whole database:

The study was GLP compliant and was performed according to OECD 414 with 2-ethylhexanol.

Effect on developmental toxicity: via inhalation route

Endpoint conclusion:

no study available

Effect on developmental toxicity: via dermal route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

840 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

Peer-reviewed publication, study according to OECD 414

Additional information

Several pivotal studies have been performed with structural analogues of UVCB 400160 (CAS No. 68334-05-4; typically consisting of 16% diesters, 43.3% monoesters, and 40.7% C18–unsaturated fatty acid dimers), in particular with 2-ethylhexanol (2-EH), the alcoholic moiety of the mono- and diesters included in 400160 as well as with medium-chain fatty acids.

Fatty acids

Originally, fatty acids (e.g. C16-C18 and C18-unsatturated) (CAS No. 67701-08-0) were exempted from the obligations to register in accordance with article 2(7)(a) according to Annex IV of Regulation (EC) No 1907/2006. However, a review of the criteria for inclusion in Annex IV (“sufficient information is known about these substances that they are considered to cause minimum risk because of their intrinsic properties”) in 2008 led to the deletion of fatty acids in Annex IV because some of the substances did not fulfil all criteria for inclusion (Commission of the European Communities, 2009). For saturated C16-C18 and C18-unsatturated fatty acids this decision was mainly based on ecotoxicological concerns and a slight skin and eye-irritating potential (DHI 2009). Data available on reproductive toxicity were considered sufficient to fulfil the Annex IV inclusion criteria. In particular, a three-generation reproductive study on a C10 fatty acid did not reveal any safety effects concerning reproduction (Hendrich et al. 1993).

Ethylhexanol

The dermal application of 2 -EH resulted in a NOAEL of 840 and ≥2520 mg/kg/day for maternal and developmental toxicity (Tyl et al. 1992). For oral application the NOAEL for maternal and developmental toxicity was 191 mg/kg bw/day for both effect types (NTP study). A lower NOAEL of 130 mg/kg/day was determined in another oral study with 2-EH in rats. This study showed significant maternal toxicity at higher doses and a lower number of animals were used as recommended in the guideline which invalidates this study to some extent.

In view of the available reproductive toxicity data, the long history of safe use of fatty acids in diet, and the fact that available reproductive toxicity data were considered sufficient to fulfil the Annex IV inclusion criteria of regulation (EC) No 1907/2006, no further developmental toxicity study with 400160 is justified.

Justification for selection of Effect on developmental toxicity: via oral route:
The study with the highest reliability was selected.

Justification for selection of Effect on developmental toxicity: via dermal route:
Only one study available

Justification for classification or non-classification

No concern arises from both raw materials of 400160 (2-ethylhexanol and dimer fatty acids) on sexual function and fertility or on development.

Therefore no classification is required for 400160.