Hydroxyoctadecanoic acid, monoester with glycerol

Endpoint summary

Key value for chemical safety assessment

Effects on fertility

Description of key information

No adverse effects observed for the analogue, castor oil

Link to relevant study records

Reference

Endpoint:

fertility, other

Remarks:

based on test type (migrated information)

Type of information:

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

Adequacy of study:

key study

Study period:

April 1988-July 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Reason / purpose for cross-reference:

read-across source

Qualifier:

equivalent or similar to guideline

Guideline:

other: Fertility measures added to a 13 week repeated dose toxicity study

Principles of method if other than guideline:

Fertility measures and pathology assessment of reproductive organs added to a guideline 13-week repeated dose toxicity study

GLP compliance:

not specified

Remarks:

Peer reviewed

Limit test:

no

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

Simonsen Laboratories, Gilroy, CA
6 weeks of age
held 14-15 days in quaranteen after receipt and before dosing
Rats housed 5/cage, mice housed individually
Polycarbonate with heat-treated wood chips
NIH-07 diet, ad libitum. Water ad libitum
Temp-68-76°F; relative humidity-42-72%; fluorescent light 12 h/d; 10 room air changes/h.
Animals were observed twice daily, weighed initially and weekly thereafter.
10 rats/sex/group in the core study.

Route of administration:

oral: feed

Vehicle:

other: rat chow (NIH 07 diet)

Details on exposure:

Formulated diets were prepared from a premix of castor oil with a small quantity of feed (NIH-07 diet). The premix was then blended with additional food using a twin shell blender. Homogeneity of castor oil in feed was documented by gravimetric analysis or HPLC. Diets were found to be stable for at least 21 days when stored in the dark at 5°C, and for 3 days when stored open to air and light in the rodent cages. Formulated diets were stored for no longer than 3 weeks at 5°C, and food in hoppers were changed twice weekly.

Details on mating procedure:

No mating

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Periodic analysis of castor oil-formulated diets was conducted by HPLC. All but a single sample were within specifications (± 10% of target concentration); the one sample was remixed before being given to animals. The range of analyses was 97% to 106% of target concentration.

Duration of treatment / exposure:

Food with added test material was available ad libitum, daily

Frequency of treatment:

daily

Details on study schedule:

Dosing was performed daily for 13 weeks

Dose / conc.:

0.62 other: % in diet

Remarks:

Approximately equivalent to 400 mg/kg bw/d (nominal)

Dose / conc.:

1.25 other: % in diet

Remarks:

Approx equal to 800 mg/kg bw/d (nominal)

Dose / conc.:

2.5 other: % in diet

Remarks:

Approx equal to 1500 mg/kg bw/d (nominal)

Dose / conc.:

5 other: % in diet

Remarks:

approximately equal to 3000 mg/kg bw/d (nominal)

Dose / conc.:

10 other: % in diet

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
- Cage side observations checked were included.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No. By cage, with 5 animals/cage.
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

Oestrous cyclicity (parental animals):

In Females, vaginal cytology was evaluated on core-study animals during the week just preceding necropsy, using the procedure of Morrissey, et.al., 1988. For the 12 days prior to termination, females were subject to vaginal lavage with saline. The aspirated cells were air-dried onto slides, stained with Toluidine Blue O and cover slips applied. The relative preponderance of leukocytes, nucleated epithelial cells and large squamous cells were used to identify the stages of the estrual cycle.

Sperm parameters (parental animals):

In males, sperm motility and morphology were evaluated on core-study at necropsy, according to Morrissey, et.al., 1988. The left epididymis was removed and quickly weighed; the cauda epididymis was removed at the junction of the vas deferens and the corpus epididymis, then weighed. A small cut was made in the distal cauda epididymis, from which the sperm were removed, and dispersed. The number of moving and non-moving sperm were counted in 5 fields of 30 sperm or less on each slide. After sperm sampling, the cauda was placed in phosphate buffered saline (PBS) and gently chopped. The solution was mixed gently and heat fixed at 65 deg C. Sperm density was then determined using a hemocytometer.

The left testes was frozen and stored. After thawing, testicular spermatid head count was determined by removing the tunica albuginea and homogenizing in PBS containing 10% DMSO. Homogenization spermatid nuclei were counted using a hemocytometer; the data were expressed as spermatid heads per total testis and per gram of testis.

Litter observations:

not applicable

Postmortem examinations (parental animals):

The following reproductive tissues were routinely processed for preparation of histologic sections and microscopic examination: epididymis, seminal vesicles, prostate and testes in males, and ovaries and uterus in females. A complete histopathologic examination was conducted on all rats and mice from the control and 10% dose groups.

Postmortem examinations (offspring):

not applicable

Statistics:

Body weight and organ weight data were statistically analyzed within each sex by one-way Analysis of Variance tests, followed by Dunnett's t-test if pair-wise comparisons were indicated (p < 0.05)(Dunnett, 1955).

Offspring viability indices:

not applicable

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not specified

Description (incidence and severity):

Not specifically examined, although clinical chemistry values are consistent with a high lipid diet.

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Hematological: males: statistically significant decrease in males in MCV in the 10% group, transient decrease in MCHC in males in the 10% group, decrease in the MCH in males of the 5 and 10% group, decreased platelets in the 1.25%, 5.0% and 10% groups. In females, there was a transient decrease in reticulocytes in the 0.62% and 10.0% groups. These effects were not biologically significant.

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

At days 5, 21 and 90, in males and females, there was a consistent dose-related increase in serum alkaline phosphatase activity in the 5 and 10% groups. Total bile acids were also statistically significantly elevated in males of the 5 and 10% groups at 5, 21 and 90 days. This is likely an adaptation to increased absorption and metabolism of lipids from the intestinal tract.

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

no effects observed

Reproductive performance:

no effects observed

No toxicologically relevant adverse effects were observed in any treatment group. Absolute liver weight and liver-to-body ratio were increased in male rats at the high dose (10% group). In males, there was a slight decrease in epididymal weight (< 10%) in the middle and high dose groups, but this was not dose-related. The small magnitude and the absence of changes in other reproductive endpoints suggested that there was little or no evidence of any reproductive toxicity associated with castor oil exposure. There were no adverse effects on sperm morphology or function. There were no adverse effects on estrous cycling in females.

In males in the highest dose group (10%), there was a statistically significant decrease in MCV; this was not considered biologically significant. Also in this group, there was a slight decrease in MCH and the MCHC was transiently decreased at day 21. Other minor effects were observed in hematologic parameters: at 90 days, the platelet count in males of the 1.25, 5 and 10% groups was significantly increased. These variations were evaluated as not biologically significant by the study authors.

Serum alkaline phosphatase activity was increased in a treatment- and dose-related manner at days 5, 21 and 90, in both males and females in the 5 and 10% groups. Total bile acids were also statistically significantly elevated in males of the 5 and 10% groups at 5, 21 and 90 days. This is likely an adaptation to increased absorption and metabolism of lipids from the intestinal tract.

Histological examination revealed an absence of compound related lesions in any organ or tissue of rat exposed to castor oil in the diet.

The NOAEL was 10% in the diet, equivalent in females to 5725 mg/kg bw/d, and in males to 5835 mg/kg bw/d.

Key result

Dose descriptor:

NOAEL

Effect level:

6 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No adverse effects were observed at the highest dose tested (10% Castor oil in the diet, equivalent to 6000 mg/kg bw/d). The NOAEL is > 6000 mg/kg bw/d.

Key result

Critical effects observed:

no

Clinical signs:

not examined

Mortality / viability:

not examined

Body weight and weight changes:

not examined

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Other effects:

not specified

Behaviour (functional findings):

not examined

Developmental immunotoxicity:

not examined

No F1 generation was established.

Key result

Dose descriptor:

other: No F1 generation established

Remarks on result:

not measured/tested

Key result

Critical effects observed:

no

Key result

Reproductive effects observed:

no

There were no observed clinical effects of dietary administration of castor oil to F344 rats for 13 weeks. The administration of diets containing up to 10% castor oil was not associated with toxicity to any specific organ, organ system or tissue, including reproductive organs, under the conditions of this study. There were no effects on sperm morphology or function in males, nor on estrous cycling in females.

Actual Dosage of Test Material in Rats

Sex	Target Concentration (% in feed)	Feed Consumption (g/kg bw/d)	Test Material Consumption (mg/kg bw/d)
Males	0	65	0
	0.62	65	404
	1.25	65	809
	2.5	63	1583
	5	61	3067
	10	58	5835
Females	0	64	0
	0.62	65	401
	1.25	64	797
	2.5	63	1569
	5	61	3045
	10	57	5725

 

Conclusions:

The effects of dietary administration of an analogue, castor oil, on the reproductive organs and estrous cycle of F344 rats were investigated in a U.S. NTP guideline repeated dose toxicity study. Diets containing up to 10% castor oil for 13 weeks were not associated with toxicity to reproductive organs, organ systems/ tissues, or reproductive function, under the conditions of this study. The NOAEL is greater than 10% in the diet, equivalent to 5725 mg/kg bw/d in females, 5835 mg/kg bw/d in males (actual). Therefore, it is reasoned that, based on a strong theoretical basis and empiric data, GMHS has no significant systemic toxicity including for reproductive toxicity.

Effect on fertility: via oral route

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

5 725 mg/kg bw/day

Study duration:

subchronic

Species:

rat

Quality of whole database:

adequate

Effect on fertility: via inhalation route

Endpoint conclusion:

no study available

Effect on fertility: via dermal route

Endpoint conclusion:

no study available

Additional information

No adverse effects observed in sperm morphology or function or oestrus cycle assessment, nor in gross or histopathologic analysis of reproductive organs in rats or mice exposed to castor oil in the diet at over 5000 mg/kg bw/d for 13 weeks.

Effects on developmental toxicity

Description of key information

No adverse effects observed

Link to relevant study records

Reference

Endpoint:

developmental toxicity

Type of 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:

guideline study with acceptable restrictions

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

yes

Limit test:

yes

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

Animals: mated Charles River Crl:CD VAF/Plus female rats, 12.5 weeks of age, weight 211 to 289 g.

Route of administration:

dermal

Details on exposure:

The test substance was applied (with gloved finger) to dorsal skin (clipped free of hair) of each animal, on gestation days 6-15, once daily, and left on for 6 hours each day. The test sites were covered (but not occluded) to prevent ingestion during the study. The control article (described as a clear liquid; no details on its composition were provided) was similarly applied to an additional group rats of the same strain.

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

received pre-mated

Duration of treatment / exposure:

Days 6-15

Frequency of treatment:

once daily, 6 hours per day

Duration of test:

20 days of gestation

Dose / conc.:

7 other: %

Remarks:

in formulation 7000 mg/kg or mg/L

No. of animals per sex per dose:

30 per formulation in 2 formulation groups

Control animals:

yes

Maternal examinations:

clinical signs, condition of skin (especially of exposed area), body weight, gross pathology, reproductive parameters (number of implantations, post-implantation loss, number of corpora lutea, number of resorptions)

Fetal examinations:

fetal sex ratio, fetal body weight, uterine weight, number of viable fetuses, number of malformations (skeletal and soft tissue), fetal variations.

Statistics:

yes, significance level p < 0.05.

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

effects observed, treatment-related

Description (incidence and severity):

Both experimental groups displayed increases in the severity of erythema and desquamation at the application sites, compared to controls. Desquamation was observed in 20 of 30 control rats, along with very slight erythema (1 control animal had weel-defined erythema).

Mortality:

no mortality observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Description (incidence and severity):

There were no significant differences between experimental and control groups in clinical or necropsy observations. There were no differences between experimental and controls groups in reproductive parameters. In both experimental and control groups, the dermal erythema and desquamation at the application site increased through the 5th and 6th days, then diminished. There was no edema noted in any group. In the control group, 10 rats had very slight erythema and one had well-defined erythema; 20 of 30 had desquamation. In one experimental group, 10 rats had very slight erythema, 10 rats had well defined erytherma, and one rat had moderate to severe erythema; desquamation occurred in 26 rats. In the other experimental group, 16 rats had very slight erythema, 6 had well-defined erythema, and 3 had moderate to severe erythema. Desquamation in this group occurred in 28 of 30 animals.

Details on maternal toxic effects:

There were no significant differences between experimental and control groups with respect to implantations, postimplantation losses, corpora lutea, fetal sex ratio, mean fetal body weight or uterine weight. The incidence of postimplantation losses/resorptions was 14 of 325 viabile fetuses in the first experimental group and 20 of 316 viable fetuses in the second experimental group.

Key result

Dose descriptor:

NOAEL

Effect level:

> 7 000 other: % in formulation

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Abnormalities:

effects observed, treatment-related

Details on embryotoxic / teratogenic effects:

There were no test article-related or statistically significant differences between experimental and control groups. The total number of litters with any malformation was comparable between experimental and control groups. In the first experimental group, the incidence of malformations was 2 of 325 viable fetuses, and in the second group, was 1 of 316 viable fetuses. Fetal variations occurred in 88 of 325 viable fetuses, in Group 1, and in 80 of 316 viable fetuses in Group 2. There were no increases in fetal malformations or variations in the experimental versus control groups.

Key result

Dose descriptor:

NOAEL

Effect level:

> 7 000 other: %; 7000 mg/kg or mg/L

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Key result

Abnormalities:

no effects observed

Key result

Developmental effects observed:

no

Conclusions:

A dermal reproductive toxicity/teratology study (OECD 414) in rats was undertaken on two formulations which included the analogue substance,12-hydroxystearic acid, at 7.0%.applied (7000 mg/kg or mg/L) for 6 hours per day, non-occlusive, during organogenesis (days 6-15). There were no increases in deaths, clinical signs, gross pathology or female reproductive parameters, compared to controls. There were no increases in fetal death, malformations or variations over control values. There were increases in erythema but not edema of the skin in experimental groups compared with controls. The dermal NOAEL for systemic maternal toxicity and fetal effects is > 7000 mg/kg or mg/L in the formulation.

Effect on developmental toxicity: via oral route

Endpoint conclusion:

no study available

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

5 725 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

adequate

Additional information

In a dermal teratology study of an analogue substance, 12 -hydroxystearic acid at 7% composition (7000 mg/kg or mg/L of formulated product), no systemic toxicologic effects were observed in parent or offspring. The critical NOAEL for risk assessment is the subchronic rat toxicity NOAEL of 5725 mg/kg be/d.

Justification for classification or non-classification

No systemic toxicity was seen with castor oil or hydrogenated castor oil in repeated dose dietary toxicity studies of at least 13-weeks duration, specifically focusing on reproductive organs and function. A NOAEL of 5725 mg/kg bw/d or higher is estimated from the NTP rat study. A teratology study (OECD 414) by the dermal route on another analogue, 12 -HSA, was found to result in no systemic parental toxicity nor adverse fetal effects when applied as a 7% formulation. The CIREP (CIR 1999, 2005) provided an assessment of the bioavailability and metabolism of analogue substances (including 12 -HSA and numerous members of a category of castor oil derivatives), concluding that there is no basis for concern for toxic effects on the reproductive system. Review of the body of existing data on the repeated dose toxicity of castor oil by the expert consulting group, DHI, on behalf of ECHA, resulted in a decision to confirm castor oil on Annex IV (later moved to Annex V).  This reflects the decision that the NOAEL is sufficiently high to warrant no concern for reproductive effects from repeated dose exposure. The OECD, when reviewing the body of data on monoglyceryl monoesters, concluded that there were no indications of toxicological effects which would warrant further hazard testing (OECD 2014).

As there is no evidence for reproductive toxicity, the substance is not classified, according to criteria in Regulation EC No, 1272/2008.