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A 90 day oral feeding study with Castor oil was performed equivalent to OECD Guideline 408 in F344/N rats and B6C3F1 mice. The test substance was mixed at concentrations of 0, 0.62, 1.25, 2.50, 5.00, 10.0 % (w/w) to the diet and the animals (10/sex/concentration) were fed ad libitum for 13 weeks. The highest concentration was equivalent to approximately 5.7 g/kg bw/day for rats and approximately 15 g/kg bw/day for mice. Exposure to castor oil at dietary concentrations as high as 10% in 13-week studies did not affect survival or body weight gains of rats or mice. There were no biologically significant effects noted in hematologic analyses in rats. Mild increases in total bile acids and in serum alkaline phosphatase were noted at various times during the studies in rats receiving the higher dietary concentrations of castor oil. Liver weights were increased in male rats receiving the 10% dietary concentration and in male and female mice receiving diets containing 5% or 10% castor oil. However, there were no histopathologic lesions associated with these liver changes, nor were there any compound-related morphologic changes in any organ in rats or mice. No significant changes were noted in a screening for male reproductive endpoints, including sperm count and motility, and no changes were observed in the length of oestrous cycles of rats or mice given diets containing castor oil. Thus, no significant adverse effects of castor oil administration were noted in these studies. A NOAEL of 5000 mg/kg bw/day for rats and a NOAEL of 15000 mg/kg bw/day for mice could be identified.

A 90 day oral feeding study with medium chain triglycerides (MCT,s) was performed similar to OECD 409 in adult beagle dogs. All dogs received on 91 consecutive days approximately 200 g of conventional feed with 0%, 5%, 10%, or 15% MCT for a three hour feeding regimen (4 animals per dose). Based on examination of clinical signs, body weight measurements, food consumption level, physical examinations, haematology and serum chemistry, ophthalmic examinations, and urinalysis the NOAEL for medium chain triglycerides was found to be greater than 15 % , which was calculated to be approximately 3750 mg/kg bw/day.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Referenceopen allclose all

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
April - July, 1988
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose for cross-reference:
reference to same study
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)
Deviations:
yes
Remarks:
: no ophthalmoscopy, no neurology
GLP compliance:
yes
Limit test:
no
Species:
mouse
Strain:
B6C3F1
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Simonsen Laboratories (Gilroy, CA, USA)
- Age at study initiation: 6 weeks
- Weight at study initiation: male: 22.6 - 23.0 g, female: 17.2 - 17.7 g
- Fasting period before study:
- Housing: individually in Polycarbonate cages lined with heat-treated hardwood chips, covered with polyester filter sheets.
- Diet (e.g. ad libitum): Control feed (NIH 07) or diet formulations of castor oil were available ad libitum; feeders were changed twice per week throughout the study.
- Water (e.g. ad libitum): automatic watering system
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 68-76°F
- Humidity (%): 42% to 72%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Formulated diets were prepared by blending the appropriate amount of castor oil with a small quantity of feed to prepare a premix. The premix then was layered between the required amount of feed in a twin-shell blender and blended for 15 minutes to achieve a uniform mix. The homogeneity of castor oil in feed at 10% (100 mg/g) was determined by gravimetric analysis, and blends at 0.5% (5 mg/g) were determined by HPLC analysis. These concentrations of chemical in feed were found to be homogeneously distributed by this mixing procedure. The stability of the 0.5% dose level was determined using HPLC; it was 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 a rodent cage. During the studies, formulated diets were stored for no longer than 3 weeks at 5°C; feed hoppers in the animal cages were changed twice weekly.

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The results of the analyses for all dose mixtures given to the animals ranged from 97% to 106% of the target concentrations.
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
daily ad libitum feeding
Remarks:
Doses / Concentrations:
0, 0.62, 1.25, 2.50, 5.00, 10.0 % (w/w)
Basis:
nominal in diet
Remarks:
Doses / Concentrations:
0, 917, 2022, 3800, 7823, 15017 mg/kg bw/day
Basis:
other: actual ingested: male mice
Remarks:
Doses / Concentrations:
0, 1153, 2282, 5009, 9627, 16786 mg/kg bw/day
Basis:
other: actual ingested: female mice
No. of animals per sex per dose:
10; 10 additional rats/sex were included at each dose level for evaluation of hematological and clinical chemistry parameters at days 5 and 21.
Control animals:
yes, plain diet
Positive control:
none
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS/ CLINICAL OBSERVATIONS: Yes
- Time schedule: twice a day

BODY WEIGHT: Yes
- Time schedule for examinations: initially and 1 x wk thereafter.

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: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: from additional rats at days 5 and 21, and at the end of study
- Anaesthetic used for blood collection: Yes, CO2
- Animals fasted: No data
- How many animals: 10 additional animals
- Parameters checked: red blood cell (RBC) count, red blood cell morphologic assessment, hematocrit (HCT), hemoglobin concentration (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), white blood cell count (WBC), white blood cell differential count, reticulocyte count (absolute), and platelet counts (absolute).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: from additional rats at days 5 and 21, and at the end of study
- Animals fasted: No data
- How many animals: 10 additional animals
- Parameters checked: alkaline phosphatase activity (ALP), albumin (ALB), urea nitrogen (UN), creatinine (CREA), alanine aminotransferase activity
(ALT), total bile acids (TBA), sorbitol dehydrogenase activity (SDH), total protein (TP), and creatinine kinase (CK).


URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Complete histopathology examinations were conducted from the control and 10% dose groups. Organ weights were determined to the nearest milligram for the liver, right kidney, right testicle, heart, thymus, and lungs. All tissues were preserved in 10% neutral buffered formalin.

The following tissues were routinely processed for preparation of histologic sections and microscopic examination: adrenal
glands, brain, cecum, colon, duodenum, epididymis/seminal vesicles/prostate/testes or ovaries/uterus, esophagus, eyes (if
grossly abnormal), femur (including marrow), heart, ileum, jejunum, kidneys, liver, lungs and mainstem bronchi, mammary
gland, mandibular and mesenteric lymph nodes, nasal cavity and turbinates, pancreas, parathyroid glands, pituitary gland,
preputial or clitoral glands, rectum, salivary glands, skin, spinal cord and sciatic nerve (if neurologic signs present), spleen,
forestomach and glandular stomach, thymus, thyroid gland, trachea, urinary bladder, zymbal glands, and all gross lesions
and tissue masses including regional lymph nodes. A complete histopathologic examination was conducted from the control and 10% dose groups.
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).
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
no adverse biologically significant effects
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:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
no adverse biologically significant effects
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
No effects

BODY WEIGHT AND WEIGHT GAIN
Mean body weights of exposed male mice generally were lower than controls, while mean body weights of exposed females generally were higher. There were no obvious indications that these differences were related to dietary concentrations of castor oil, except that mean body weights of male mice receiving the 10% castor oil diet were consistently lower than those of control mice from week 3 through the end of the study.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
No significant differences in average food consumption among each sex were observed, although food consumption by female mice receiving diets containing 10% castor oil was slightly lower than controls.

HAEMATOLOGY
No changes were observed.

CLINICAL CHEMISTRY
No changes were observed.

ORGAN WEIGHTS
Liver weights were increased in male and female mice that received diets containing 5% or 10% castor oil. Kidney weights were increased in female mice that received 5% or 10% diets. Using light microscopy, it was determined that there were no morphologic changes associated with the slight differences between groups in organ weights. Histopathologic examination revealed an absence of compound-related lesions in any organs or tissues of mice exposed to castor oil in the diet.

OTHER FINDINGS
Castor oil exposure produced no adverse effects on any male (testes weight, epididymal sperm motility, density, or testicular spermatid head count) or female (estrual cycle length, or time spent in each phase of the cycle) reproductive parameter among mice. The low value for sperm motility in control mice was attributed to poor preparative technique.
Dose descriptor:
NOAEL
Effect level:
ca. 15 000 mg/kg bw/day (actual dose received)
Based on:
other: calculated test material intake based on food consumption and body weight
Sex:
male/female
Basis for effect level:
other: mice; based on clinical signs; mortality; body weight; food consumption; haematology; clinical chemistry; gross pathology; organ weights; histopathology;
Critical effects observed:
not specified
Conclusions:
In a 90 days oral feeding study in mice the NOAEL was 15.000 mg/kg bw/d.
Executive summary:

Castor oil is a natural oil derived from the seeds of the castor bean, Ricinus communis. It is comprised largely of triglycerides with a high ricinolin content. Toxicity studies with castor oil were performed by incorporating the material at concentrations as high as 10% in diets given to B6C3F1 mice of both sexes for 13 weeks.

Exposure to castor oil at dietary concentrations as high as 10% in 13-week studies did not affect survival or body weight gains of mice (10 per sex and dose). Liver weights were increased in male and female mice receiving diets containing 5% or 10% castor oil. However, there were no histopathologic lesions associated with these liver changes, nor were there any compound-related morphologic changes in any organ. No significant changes were noted in a screening for male reproductive endpoints, including sperm count and motility, and no changes were observed in the length of estrous cycles of rats or mice given diets containing castor oil. Thus, no adverse effects of castor oil administration were noted in these studies.

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
April - July, 1988
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose for cross-reference:
reference to same study
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 408 (Repeated Dose 90-Day Oral Toxicity Study in Rodents)
Deviations:
yes
Remarks:
: no ophthalmoscopy, no neurology
GLP compliance:
yes
Limit test:
no
Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Simonsen Laboratories (Gilroy, CA, USA)
- Age at study initiation: 6 weeks
- Weight at study initiation: male: 126 - 132 g; female: 107- 110 g
- Housing: rats: 5 per cage
- Diet (e.g. ad libitum): Control feed (NIH 07) or diet formulations of castor oil were available ad libitum; feeders were changed twice per week throughout the study.
- Water (e.g. ad libitum): automatic watering system
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 68-76°F
- Humidity (%): 42% to 72%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Formulated diets were prepared by blending the appropriate amount of castor oil with a small quantity of feed to prepare a premix. The premix then was layered between the required amount of feed in a twin-shell blender and blended for 15 minutes to achieve a uniform mix. The homogeneity of castor oil in feed at 10% (100 mg/g) was determined by gravimetric analysis, and blends at 0.5% (5 mg/g) were determined by HPLC analysis. These concentrations of chemical in feed were found to be homogeneously distributed by this mixing procedure. The stability of the 0.5% dose level was determined using HPLC; it was 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 a rodent cage. During the studies, formulated diets were stored for no longer than 3 weeks at 5°C; feed hoppers in the animal cages were changed twice weekly.

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The results of the analyses for all dose mixtures given to the animals ranged from 97% to 106% of the target concentrations.
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
daily ad libitum feeding
Remarks:
Doses / Concentrations:
0, 0.62, 1.25, 2.50, 5.00, 10.0 % (w/w)
Basis:
nominal in diet
Remarks:
Doses / Concentrations:
0, 404, 809, 1583, 3067 and 5835 mg/kg bw/day
Basis:
other: actual ingested: male rats
Remarks:
Doses / Concentrations:
0, 401, 797, 1569, 3045, 5725 mg/kg bw/day
Basis:
other: actual ingested: female rats
No. of animals per sex per dose:
10; 10 additional rats/sex were included at each dose level for evaluation of hematological and clinical chemistry parameters at days 5 and 21.
Control animals:
yes, plain diet
Positive control:
none
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS/ CLINICAL OBSERVATIONS: Yes
- Time schedule: twice a day

BODY WEIGHT: Yes
- Time schedule for examinations: initially and 1 x wk thereafter.

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: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: from additional rats at days 5 and 21, and at the end of study
- Anaesthetic used for blood collection: Yes, CO2
- Animals fasted: No data
- How many animals: 10 additional animals
- Parameters checked: red blood cell (RBC) count, red blood cell morphologic assessment, hematocrit (HCT), hemoglobin concentration (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), white blood cell count (WBC), white blood cell differential count, reticulocyte count (absolute), and platelet counts (absolute).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: from additional rats at days 5 and 21, and at the end of study
- Animals fasted: No data
- How many animals: 10 additional animals
- Parameters checked: alkaline phosphatase activity (ALP), albumin (ALB), urea nitrogen (UN), creatinine (CREA), alanine aminotransferase activity
(ALT), total bile acids (TBA), sorbitol dehydrogenase activity (SDH), total protein (TP), and creatinine kinase (CK).


URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Complete histopathology examinations were conducted on all rats from the control and 10% dose groups. Livers were examined from male rats in all other dose groups; histologic sections of gross lesions were examined from all rats. Organ weights were determined to the nearest milligram for the liver, right kidney, right testicle, heart, thymus, and lungs. All tissues were preserved in 10% neutral buffered formalin.

The following tissues were routinely processed for preparation of histologic sections and microscopic examination: adrenal
glands, brain, cecum, colon, duodenum, epididymis/seminal vesicles/prostate/testes or ovaries/uterus, esophagus, eyes (if
grossly abnormal), femur (including marrow), heart, ileum, jejunum, kidneys, liver, lungs and mainstem bronchi, mammary
gland, mandibular and mesenteric lymph nodes, nasal cavity and turbinates, pancreas, parathyroid glands, pituitary gland,
preputial or clitoral glands, rectum, salivary glands, skin, spinal cord and sciatic nerve (if neurologic signs present), spleen,
forestomach and glandular stomach, thymus, thyroid gland, trachea, urinary bladder, zymbal glands, and all gross lesions
and tissue masses including regional lymph nodes. A complete histopathologic examination was conducted on all rats from the control and 10% dose groups. Liver was examined from male rats in all other dose groups, and histologic
sections of gross lesions were examined from all rats.
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).
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 examined
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):
no adverse biologically significant effects
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
no adverse biologically significant effects
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
no adverse biologically significant effects
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
No effects

BODY WEIGHT AND WEIGHT GAIN
Group mean body weights of rats receiving diets containing castor oil did not differ significantly from controls. Mean body weights of exposed female rats were slightly lower than the mean body weights of controls but the differences were not dose-related.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
No significant differences in average food consumption among each sex were observed, although food consumption of male and female rats receiving diets containing 10% castor oil was slightly lower than that of controls.

HAEMATOLOGY
Hematological effects of the castor oil diets among male rats included a slight decrease in MCHC at day 21 in those receiving the 10% diet; a statistically significant decrease in MCV among the 10% group; a decrease in MCH among the 5% and 10% groups; and an increase in platelets among the 1.25%, 5%, and 10% groups. The only change observed among female rats was a statistically significant decrease in reticulocyte counts at day 5 in groups receiving the 0.62% or 10% diets. None of these changes was considered biologically significant.

CLINICAL CHEMISTRY
A treatment- and dose-related increase in the activity of serum alkaline phosphatase was observed in male and female rats at days 5 and 21, and at study termination. Total bile acids were increased among males receiving the higher dietary levels at days 5 and 21 but were not increased at study termination. Other minor changes included increases in albumin observed at study termination in males receiving 5% diets and at day 5 in females receiving 10% diets, and an increase in urea nitrogen at study termination in males that received 0.62% diets and a decrease at day 5 in females that received castor oil at 10% in the diet.

ORGAN WEIGHTS
Absolute liver weights and the liver-to-body-weight ratio were increased in male rats that received diets containing 10% castor oil. Heart-to-body-weight ratios were increased in groups of male rats receiving 0.62%, 2.5%, and 10% diets; however, absolute heart weights were not increased, and the differences in body weight ratios were small and not considered treatment related. Using light microscopy, it was determined there were no morphologic changes associated with the slight differences in organ weights between groups.

In male rats, there was a slight decrease in epididymal weight (6-7%) which occurred in the middle- and high-dose groups, but this was not dose-related. There were no effects on any other male rat reproductive endpoint, or on any female rat reproductive endpoint. Although there was some variation in epididymal weights, their small magnitude and the absence of changes in other endpoints suggested that there was little or no evidence of any reproductive toxicity associated with castor oil exposure (Appendix A). Histopathologic examination revealed an absence of compound-related lesions in any organ or tissue of rats exposed to castor oil in the diet.
Dose descriptor:
NOAEL
Effect level:
ca. 5 000 mg/kg bw/day (actual dose received)
Based on:
other: calculated test material intake based on food consumption and body weight
Sex:
male/female
Basis for effect level:
other: rats; no effects observed based on clinical signs; mortality; body weight; food consumption; haematology; clinical chemistry; gross pathology; organ weights; histopathology;
Critical effects observed:
not specified
Conclusions:
In a 90 days oral feeding study in rats the NOAEL was 5000 mg/kg bw/d.
Executive summary:

Castor oil is a natural oil derived from the seeds of the castor bean, Ricinus communis. It is comprised largely of triglycerides with a high ricinolin content. Toxicity studies with castor oil were performed by incorporating the material at concentrations as high as 10% in diets given to F344/N rats of both sexes for 13 weeks.

Exposure to castor oil at dietary concentrations as high as 10% in a 13 -week study did not affect survival or body weight gains of rats (10 per sex and dose). There were no biologically significant effects noted in hematologic analyses in rats. Mild increases in total bile acids and in serum alkaline phosphatase were noted at various times during the studies in rats receiving the higher dietary concentrations of castor oil. Liver weights were increased in male rats receiving the 10% dietary concentration of castor oil. However, there were no histopathologic lesions associated with these liver changes, nor were there any compound-related morphologic changes in any organ. No significant changes were noted in a screening for male reproductive endpoints, including sperm count and motility, and no changes were observed in the length of estrous cycles. Thus, no adverse effects of castor oil administration were noted in these studies.

Endpoint:
sub-chronic toxicity: oral
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
Remarks:
Read-across to K1 study therefore K2 is the highest Klimisch score that can be assigned
Justification for type of information:
Please see the read-across report attached in section 13 of this dossier.
Reason / purpose for cross-reference:
read-across source
Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Simonsen Laboratories (Gilroy, CA, USA)
- Age at study initiation: 6 weeks
- Weight at study initiation: male: 126 - 132 g; female: 107- 110 g
- Housing: rats: 5 per cage
- Diet (e.g. ad libitum): Control feed (NIH 07) or diet formulations of castor oil were available ad libitum; feeders were changed twice per week throughout the study.
- Water (e.g. ad libitum): automatic watering system
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 68-76°F
- Humidity (%): 42% to 72%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Formulated diets were prepared by blending the appropriate amount of castor oil with a small quantity of feed to prepare a premix. The premix then was layered between the required amount of feed in a twin-shell blender and blended for 15 minutes to achieve a uniform mix. The homogeneity of castor oil in feed at 10% (100 mg/g) was determined by gravimetric analysis, and blends at 0.5% (5 mg/g) were determined by HPLC analysis. These concentrations of chemical in feed were found to be homogeneously distributed by this mixing procedure. The stability of the 0.5% dose level was determined using HPLC; it was 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 a rodent cage. During the studies, formulated diets were stored for no longer than 3 weeks at 5°C; feed hoppers in the animal cages were changed twice weekly.

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The results of the analyses for all dose mixtures given to the animals ranged from 97% to 106% of the target concentrations.
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
daily ad libitum feeding
Remarks:
Doses / Concentrations:
0, 0.62, 1.25, 2.50, 5.00, 10.0 % (w/w)
Basis:
nominal in diet
Remarks:
Doses / Concentrations:
0, 404, 809, 1583, 3067 and 5835 mg/kg bw/day
Basis:
other: actual ingested: male rats
Remarks:
Doses / Concentrations:
0, 401, 797, 1569, 3045, 5725 mg/kg bw/day
Basis:
other: actual ingested: female rats
No. of animals per sex per dose:
10; 10 additional rats/sex were included at each dose level for evaluation of hematological and clinical chemistry parameters at days 5 and 21.
Control animals:
yes, plain diet
Positive control:
none
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS/ CLINICAL OBSERVATIONS: Yes
- Time schedule: twice a day

BODY WEIGHT: Yes
- Time schedule for examinations: initially and 1 x wk thereafter.

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: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: from additional rats at days 5 and 21, and at the end of study
- Anaesthetic used for blood collection: Yes, CO2
- Animals fasted: No data
- How many animals: 10 additional animals
- Parameters checked: red blood cell (RBC) count, red blood cell morphologic assessment, hematocrit (HCT), hemoglobin concentration (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), white blood cell count (WBC), white blood cell differential count, reticulocyte count (absolute), and platelet counts (absolute).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: from additional rats at days 5 and 21, and at the end of study
- Animals fasted: No data
- How many animals: 10 additional animals
- Parameters checked: alkaline phosphatase activity (ALP), albumin (ALB), urea nitrogen (UN), creatinine (CREA), alanine aminotransferase activity
(ALT), total bile acids (TBA), sorbitol dehydrogenase activity (SDH), total protein (TP), and creatinine kinase (CK).


URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Complete histopathology examinations were conducted on all rats from the control and 10% dose groups. Livers were examined from male rats in all other dose groups; histologic sections of gross lesions were examined from all rats. Organ weights were determined to the nearest milligram for the liver, right kidney, right testicle, heart, thymus, and lungs. All tissues were preserved in 10% neutral buffered formalin.

The following tissues were routinely processed for preparation of histologic sections and microscopic examination: adrenal
glands, brain, cecum, colon, duodenum, epididymis/seminal vesicles/prostate/testes or ovaries/uterus, esophagus, eyes (if
grossly abnormal), femur (including marrow), heart, ileum, jejunum, kidneys, liver, lungs and mainstem bronchi, mammary
gland, mandibular and mesenteric lymph nodes, nasal cavity and turbinates, pancreas, parathyroid glands, pituitary gland,
preputial or clitoral glands, rectum, salivary glands, skin, spinal cord and sciatic nerve (if neurologic signs present), spleen,
forestomach and glandular stomach, thymus, thyroid gland, trachea, urinary bladder, zymbal glands, and all gross lesions
and tissue masses including regional lymph nodes. A complete histopathologic examination was conducted on all rats from the control and 10% dose groups. Liver was examined from male rats in all other dose groups, and histologic
sections of gross lesions were examined from all rats.
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).
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 examined
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):
no adverse biologically significant effects
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
no adverse biologically significant effects
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
no adverse biologically significant effects
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
No effects

BODY WEIGHT AND WEIGHT GAIN
Group mean body weights of rats receiving diets containing castor oil did not differ significantly from controls. Mean body weights of exposed female rats were slightly lower than the mean body weights of controls but the differences were not dose-related.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
No significant differences in average food consumption among each sex were observed, although food consumption of male and female rats receiving diets containing 10% castor oil was slightly lower than that of controls.

HAEMATOLOGY
Hematological effects of the castor oil diets among male rats included a slight decrease in MCHC at day 21 in those receiving the 10% diet; a statistically significant decrease in MCV among the 10% group; a decrease in MCH among the 5% and 10% groups; and an increase in platelets among the 1.25%, 5%, and 10% groups. The only change observed among female rats was a statistically significant decrease in reticulocyte counts at day 5 in groups receiving the 0.62% or 10% diets. None of these changes was considered biologically significant.

CLINICAL CHEMISTRY
A treatment- and dose-related increase in the activity of serum alkaline phosphatase was observed in male and female rats at days 5 and 21, and at study termination. Total bile acids were increased among males receiving the higher dietary levels at days 5 and 21 but were not increased at study termination. Other minor changes included increases in albumin observed at study termination in males receiving 5% diets and at day 5 in females receiving 10% diets, and an increase in urea nitrogen at study termination in males that received 0.62% diets and a decrease at day 5 in females that received castor oil at 10% in the diet.

ORGAN WEIGHTS
Absolute liver weights and the liver-to-body-weight ratio were increased in male rats that received diets containing 10% castor oil. Heart-to-body-weight ratios were increased in groups of male rats receiving 0.62%, 2.5%, and 10% diets; however, absolute heart weights were not increased, and the differences in body weight ratios were small and not considered treatment related. Using light microscopy, it was determined there were no morphologic changes associated with the slight differences in organ weights between groups.

In male rats, there was a slight decrease in epididymal weight (6-7%) which occurred in the middle- and high-dose groups, but this was not dose-related. There were no effects on any other male rat reproductive endpoint, or on any female rat reproductive endpoint. Although there was some variation in epididymal weights, their small magnitude and the absence of changes in other endpoints suggested that there was little or no evidence of any reproductive toxicity associated with castor oil exposure (Appendix A). Histopathologic examination revealed an absence of compound-related lesions in any organ or tissue of rats exposed to castor oil in the diet.
Dose descriptor:
NOAEL
Effect level:
ca. 5 000 mg/kg bw/day (actual dose received)
Based on:
other: calculated test material intake based on food consumption and body weight
Sex:
male/female
Basis for effect level:
other: rats; no effects observed based on clinical signs; mortality; body weight; food consumption; haematology; clinical chemistry; gross pathology; organ weights; histopathology;
Critical effects observed:
not specified
Conclusions:
In a 90 days oral feeding study in rats the NOAEL was 5000 mg/kg bw/d.
Executive summary:

Castor oil is a natural oil derived from the seeds of the castor bean, Ricinus communis. It is comprised largely of triglycerides with a high ricinolin content. Toxicity studies with castor oil were performed by incorporating the material at concentrations as high as 10% in diets given to F344/N rats of both sexes for 13 weeks.

Exposure to castor oil at dietary concentrations as high as 10% in a 13 -week study did not affect survival or body weight gains of rats (10 per sex and dose). There were no biologically significant effects noted in hematologic analyses in rats. Mild increases in total bile acids and in serum alkaline phosphatase were noted at various times during the studies in rats receiving the higher dietary concentrations of castor oil. Liver weights were increased in male rats receiving the 10% dietary concentration of castor oil. However, there were no histopathologic lesions associated with these liver changes, nor were there any compound-related morphologic changes in any organ. No significant changes were noted in a screening for male reproductive endpoints, including sperm count and motility, and no changes were observed in the length of estrous cycles. Thus, no adverse effects of castor oil administration were noted in these studies.

Endpoint:
sub-chronic toxicity: oral
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
guideline study
Remarks:
Read-across to K1 study therefore K2 is the highest score that can be assigned.
Justification for type of information:
Please see the read-across report attached in section 13 of this dossier.
Reason / purpose for cross-reference:
read-across source
Species:
mouse
Strain:
B6C3F1
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Simonsen Laboratories (Gilroy, CA, USA)
- Age at study initiation: 6 weeks
- Weight at study initiation: male: 22.6 - 23.0 g, female: 17.2 - 17.7 g
- Fasting period before study:
- Housing: individually in Polycarbonate cages lined with heat-treated hardwood chips, covered with polyester filter sheets.
- Diet (e.g. ad libitum): Control feed (NIH 07) or diet formulations of castor oil were available ad libitum; feeders were changed twice per week throughout the study.
- Water (e.g. ad libitum): automatic watering system
- Acclimation period: 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°F): 68-76°F
- Humidity (%): 42% to 72%
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:
Formulated diets were prepared by blending the appropriate amount of castor oil with a small quantity of feed to prepare a premix. The premix then was layered between the required amount of feed in a twin-shell blender and blended for 15 minutes to achieve a uniform mix. The homogeneity of castor oil in feed at 10% (100 mg/g) was determined by gravimetric analysis, and blends at 0.5% (5 mg/g) were determined by HPLC analysis. These concentrations of chemical in feed were found to be homogeneously distributed by this mixing procedure. The stability of the 0.5% dose level was determined using HPLC; it was 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 a rodent cage. During the studies, formulated diets were stored for no longer than 3 weeks at 5°C; feed hoppers in the animal cages were changed twice weekly.

Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
The results of the analyses for all dose mixtures given to the animals ranged from 97% to 106% of the target concentrations.
Duration of treatment / exposure:
13 weeks
Frequency of treatment:
daily ad libitum feeding
Remarks:
Doses / Concentrations:
0, 0.62, 1.25, 2.50, 5.00, 10.0 % (w/w)
Basis:
nominal in diet
Remarks:
Doses / Concentrations:
0, 917, 2022, 3800, 7823, 15017 mg/kg bw/day
Basis:
other: actual ingested: male mice
Remarks:
Doses / Concentrations:
0, 1153, 2282, 5009, 9627, 16786 mg/kg bw/day
Basis:
other: actual ingested: female mice
No. of animals per sex per dose:
10; 10 additional rats/sex were included at each dose level for evaluation of hematological and clinical chemistry parameters at days 5 and 21.
Control animals:
yes, plain diet
Positive control:
none
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS/ CLINICAL OBSERVATIONS: Yes
- Time schedule: twice a day

BODY WEIGHT: Yes
- Time schedule for examinations: initially and 1 x wk thereafter.

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: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: from additional rats at days 5 and 21, and at the end of study
- Anaesthetic used for blood collection: Yes, CO2
- Animals fasted: No data
- How many animals: 10 additional animals
- Parameters checked: red blood cell (RBC) count, red blood cell morphologic assessment, hematocrit (HCT), hemoglobin concentration (HGB), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), white blood cell count (WBC), white blood cell differential count, reticulocyte count (absolute), and platelet counts (absolute).

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: from additional rats at days 5 and 21, and at the end of study
- Animals fasted: No data
- How many animals: 10 additional animals
- Parameters checked: alkaline phosphatase activity (ALP), albumin (ALB), urea nitrogen (UN), creatinine (CREA), alanine aminotransferase activity
(ALT), total bile acids (TBA), sorbitol dehydrogenase activity (SDH), total protein (TP), and creatinine kinase (CK).


URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Complete histopathology examinations were conducted from the control and 10% dose groups. Organ weights were determined to the nearest milligram for the liver, right kidney, right testicle, heart, thymus, and lungs. All tissues were preserved in 10% neutral buffered formalin.

The following tissues were routinely processed for preparation of histologic sections and microscopic examination: adrenal
glands, brain, cecum, colon, duodenum, epididymis/seminal vesicles/prostate/testes or ovaries/uterus, esophagus, eyes (if
grossly abnormal), femur (including marrow), heart, ileum, jejunum, kidneys, liver, lungs and mainstem bronchi, mammary
gland, mandibular and mesenteric lymph nodes, nasal cavity and turbinates, pancreas, parathyroid glands, pituitary gland,
preputial or clitoral glands, rectum, salivary glands, skin, spinal cord and sciatic nerve (if neurologic signs present), spleen,
forestomach and glandular stomach, thymus, thyroid gland, trachea, urinary bladder, zymbal glands, and all gross lesions
and tissue masses including regional lymph nodes. A complete histopathologic examination was conducted from the control and 10% dose groups.
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).
Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
no adverse biologically significant effects
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:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Description (incidence and severity):
no adverse biologically significant effects
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
no effects observed
Histopathological findings: neoplastic:
no effects observed
Details on results:
CLINICAL SIGNS AND MORTALITY
No effects

BODY WEIGHT AND WEIGHT GAIN
Mean body weights of exposed male mice generally were lower than controls, while mean body weights of exposed females generally were higher. There were no obvious indications that these differences were related to dietary concentrations of castor oil, except that mean body weights of male mice receiving the 10% castor oil diet were consistently lower than those of control mice from week 3 through the end of the study.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
No significant differences in average food consumption among each sex were observed, although food consumption by female mice receiving diets containing 10% castor oil was slightly lower than controls.

HAEMATOLOGY
No changes were observed.

CLINICAL CHEMISTRY
No changes were observed.

ORGAN WEIGHTS
Liver weights were increased in male and female mice that received diets containing 5% or 10% castor oil. Kidney weights were increased in female mice that received 5% or 10% diets. Using light microscopy, it was determined that there were no morphologic changes associated with the slight differences between groups in organ weights. Histopathologic examination revealed an absence of compound-related lesions in any organs or tissues of mice exposed to castor oil in the diet.

OTHER FINDINGS
Castor oil exposure produced no adverse effects on any male (testes weight, epididymal sperm motility, density, or testicular spermatid head count) or female (estrual cycle length, or time spent in each phase of the cycle) reproductive parameter among mice. The low value for sperm motility in control mice was attributed to poor preparative technique.
Dose descriptor:
NOAEL
Effect level:
ca. 15 000 mg/kg bw/day (actual dose received)
Based on:
other: calculated test material intake based on food consumption and body weight
Sex:
male/female
Basis for effect level:
other: mice; based on clinical signs; mortality; body weight; food consumption; haematology; clinical chemistry; gross pathology; organ weights; histopathology;
Critical effects observed:
not specified
Conclusions:
In a 90 days oral feeding study in mice the NOAEL was 15.000 mg/kg bw/d.
Executive summary:

Castor oil is a natural oil derived from the seeds of the castor bean, Ricinus communis. It is comprised largely of triglycerides with a high ricinolin content. Toxicity studies with castor oil were performed by incorporating the material at concentrations as high as 10% in diets given to B6C3F1 mice of both sexes for 13 weeks.

Exposure to castor oil at dietary concentrations as high as 10% in 13-week studies did not affect survival or body weight gains of mice (10 per sex and dose). Liver weights were increased in male and female mice receiving diets containing 5% or 10% castor oil. However, there were no histopathologic lesions associated with these liver changes, nor were there any compound-related morphologic changes in any organ. No significant changes were noted in a screening for male reproductive endpoints, including sperm count and motility, and no changes were observed in the length of estrous cycles of rats or mice given diets containing castor oil. Thus, no adverse effects of castor oil administration were noted in these studies.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
5 000 mg/kg bw/day
Study duration:
subchronic
Species:
rat
Quality of whole database:
Sufficient to address requirements.

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion
Endpoint conclusion:
no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion
Endpoint conclusion:
no study available

Additional information

Citric acid esters of mono- and diglycerides are current EU approved food additives (= E 472c), and have been considered by the Scientific Committee on Food (SCF) on several occasions. In 1978, the SCF endorsed the “ADI not specified” for citric acid esters of mono- and diglycerides allocated by the Joint FAO/WHO Expert Committee on Food Additives (WHO, 1974; SCF, 1978). Subsequently, the Committee considered the use of E 472c was acceptable in weaning foods in biscuits, cereal-based and baby foods (SCF, 1990). In 1997, the SCF concluded that the use of E 472c was acceptable in products for infants and young children and in foods for special medical purposes (FSMPs) (SCF, 1998). This advice was implemented in Directive 95/2/EC as amended by Directive 98/72/EC and extended in 2002 (Opinion of the SCF on Citric acid esters of mono- and diglyglycerides (E472c): request for additional uses in foods for special medical purposes for infants and young children). In addition, Glycerol stearate; Glycerides, C 16-18 and C 18 –unsaturated; Glycerides, tallow mono-, di- and tri-, hydrogenated; and Glycerides, C 16-18 and C 18 -unsaturated, mono- and di- are listed on Annex IV to REACH as causing minimum risk because of their intrinsic properties.

Justification for classification or non-classification

Based on the findings of a reliable 13-week sub-chronic feeding toxicity study conducted on castor oil (a structural analogue) in rats and mice, classification of the substance is not justified.