Calcium di(octanoate)

Endpoint summary

Description of key information

There were no changes in the sex ratio, weight, and survival rate of offspring attributed to the effects of docosanic acid administration. In addition, morphological abnormalities in offspring were not observed in any docosanic acid administration group. These results conclude that under these test conditions, the NOAEL for repeated administration of docosanic acid in regard to toxicity is 1000 mg/kg/day.

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose 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:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

1. HYPOTHESIS FOR THE ANALOGUE APPROACH
The target substance consists of calcium salts of fatty acids. Since the test item is an organic salt which dissociates in an aqueous solute, only the carboxylate (i.e. octanoate) has been considered therefore the chosen source substance consists of C22 fatty acids, rather than metal salts of fatty acids. The fatty acids differ by chain length, with the source substance being C22 and the target substance being C8. However, these will all break down to intermediate fatty acids, including glycerol, and finally carbon dioxide and water.

2. SOURCE AND TARGET CHEMICAL(S) (INCLUDING INFORMATION ON PURITY AND IMPURITIES)
See Test material sections of the source and target records for details.

3. ANALOGUE APPROACH JUSTIFICATION
In experimental tests for organic salts, the concentration of the counter-ion is usually not measured and only the organic ion (or its neutral form) is monitored. Moreover the medium used to conduct toxicological and ecotoxicological assays is buffered at a pH between 6 – 9, where there is an equilibrium between the non-ionized form (free acid) and the ionised form (carboxylate), and both are present in the test medium, no matter if the acid or a salt of it was introduced first. In fact, at this pH, most of the substance will be in its ionized form (carboxylate). Consequently, the toxicity properties of the test item are based on those of octanoic acid, which is a C8 fatty acid. The toxicological properties of fatty acids in general are therefore relevant to this substance.
Fatty acids are an endogenous part of every living cell and are absorbed, digested and transported in animals and humans. When taken up by tissues, they can either be stored as triglycerides or can be oxidised via the ß-oxidation and tricarboxylic acid pathways. The fatty acid moieties of calcium salts of fatty acids are natural constituents of the human body and essential components of a balanced human nutrition. Fatty acids, through their inclusion in REACH Annex V, are excluded from REACH registration requirements provided they are obtained from natural sources and not chemically modified, are not PBT or vPvB or give rise to an equivalent level of concern, and do not meet the criteria for classification as dangerous, except those classified only as flammable or skin or eye irritants.

Further information is included in the read-across justification attached to Section 13 of IUCLID.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Details on species / strain selection:

Crj: CD,SPF

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Japan, Hino, Tokyo
- Age at study initiation: 8 weeks
- Weight at study initiation: male: 312.1 - 363.7 g; female: 205.3 - 230.8 g
- Housing: metal wire floor cages
- Diet: ad libitum CE-2, CLEA Japan
- Water: ad libitum tap water
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 ± 1
- Humidity (%): 50 - 65
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
prepared more frequently than once a week; aliquots were kept by each concentration refrigerated in airtight conditions

VEHICLE
- Justification for use and choice of vehicle (if other than water): due to insolubility in water
- Amount of vehicle (if gavage): 5 mL/kg bw
- Lot/batch no. (if required): V6H2050

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

- males: 42 days
- females: from 14 days prior to mating to day 3 of lactation

Frequency of treatment:

Once daily

Dose / conc.:

100 mg/kg bw/day (actual dose received)

Dose / conc.:

300 mg/kg bw/day (actual dose received)

Dose / conc.:

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

No. of animals per sex per dose:

13

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: based on preliminary result in a 14 day-repeated dose toxicity study, where no signs of toxicity were found

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: at least once a day

DETAILED CLINICAL OBSERVATIONS: No

BODY WEIGHT: Yes
- Time schedule for examinations: males: days 1, 8, 15, 22, 29, 36, 42; pregnancy females: premating days 1, 8, 15; pregnancy days: 0, 7, 14, 20; lactation days: 0, 4; non pregnancy females: day 1, 8, 15, 22, 25

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

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes (males only)
- Time schedule for collection of blood: prior to autopsy
- Anaesthetic used for blood collection: Yes (identity): pentobarbital sodium
- Animals fasted: 18 - 24 hours before sacrifice
- How many animals: all surviving animals
- Parameters checked: red blood cell count (RBC), white blood cell count (WBC), haemoglobin content (Hb), mean corpuscular volume (MCV), haematocrit (Ht), mean corpuscular haemoglobin content (MCH), mean corpuscular haemoglobin concentration (MCHC)

CLINICAL CHEMISTRY: Yes (males only)
- Animals fasted: 18 - 24 hours before sacrifice
- How many animals: all surviving animals
- Parameters checked: total protein, albumin, total cholesterol concentration, glucose, urea nitrogen, creatinine, alkaline phosphatase activity, GOT, GPT, γ-GTP, triglyceride concentration, inorganic phosphorus, total bilirubin, calcium, sodium, potassium, chlorine, A/G ratio

URINALYSIS: No

Sacrifice and pathology:

Animals were fasted for 24 hours after the final administration.

Gross Pathology
Organ weights:
male: heart, liver, kidneys, thymus, testes, epididymides
female: heart, liver, kidneys, thymus, ovaries and uterus

Pathology and histopathology (control and 1000 mg/kg bw/day group):
male: heart, liver, spleen, kidney, adrenal, testis, epididymis, brain, thymus, bladder
Testes and epididymides were stored by fixing in buan solution, all other organs were fixed in 10% formalin. Paraffin sections were produced and histopathological examination was performed using hematoxylin-eosin staining.

female: brain,heart, liver, spleen, kidney, bladder, adrenal glands, thymus, uterus, ovaries
Ovaries were stored by fixing in buan solution, all other organs were fixed in 10% formalin. Sections were prepared and histopathological examination was performed.

Blood chemistry:
Males: blood was taken from a vein in the abdomen under sodium pentobarbital anesthesa.
The numbder of red blood cells (RBC), leukocytes (WBC), blood pigment (Hb), average red blood cell volume (MCV) were calculated. Platelet count was carried out using a Coulter Counter Model S-PLUS IV.
Average erythrocyte blood pigment (MCH), average erythrocyte blood pigment concentration (MCHC) were also examined. The leukocyte percentile ratio was calculated by staining the specimens with Geisma and Wright stain and examined under and optical microscope.
Following blood collection the presence of peptides was determined using the Biuret method. Albumin concentration (BCG), total cholesterol levels (COD), glucose concentration (Glucokinase G6PD), urea nitrogen concentration (UreaseGt.DH), creatinine concentration (Jaff), alkaline phosphatase activity (Paranitophenyl phosphate substrate method), GOT/GPT activity (SSCC) - (y-GTPActivityCGlutamyl-3-Carboxy-4-Nitroanirid substrate method), triglyceride concentration (GPO), inorganic phosphorus concentration (Molybdate Direct method), total bilirubin concentration (Bilirubin [Roche' KitSSeries), calcium concentration (OCPC), potassium concentration (ion electrode method), chlorine concentration (ion electrode method) were examined.

Statistics:

Yates test, Mann-Whitney U test, Fisher exact test, Bartlett test, Dunnett test, Scheffe test, Kruskal-Wallis test

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

significant increase was observed in 100 mg/kg bw/day group, not considered to be related to treatment

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

significant decrease was observed in 100 mg/kg bw/day group during lactation, not considered to be related to treatment

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, non-treatment-related

Description (incidence and severity):

significant decrease of mean corpuscular haemoglobin concentration in the 300 and 1000 mg/kg bw/day groups; fndings are not dose-dependent

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

significant decreased ALP level in all dose groups; significant decreased glucose level in the 1000 mg/kg bw/day group; signifant increase in chloride, decrease in calcium content and in total protein in the 300 mg/kg bw/day group; fndings are not dose-dependent and considered incidental

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

kidney weight significantly reduced (p<0.05) in the 300 mg/kg bw group in females; significant increased actual weight ratio of liver weight (p <0.05) in the 100 mg/kg bw/day group; considered as incidental

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

observations were considered incidential

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

observations were considered incidential

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
- Males: No deaths or abnormalities in general condition were observed in any of the treated groups
- Females: No deaths were observed in any treated group

BODY WEIGHT AND WEIGHT GAIN
- Males: significant increase (p<0.01) compared to control was observed in 100 mg/kg bw/day group between 8 - 15 days and between 15 - 29 days. However, since no change was observed in other groups, it was considered not related to the dosing of compound.
- Females: no significant changes in body weight were noted

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
- Males: no changes in food consumption related to the dosing of compound
- Females: significant decrease (p<0.01) compared to control was observed during lactation in 100 mg/kg bw/day group. However, since no other changes in food consumption were noted in 300 mg/kg bw/day and 1000 mg/kg bw/day, it was not related to the dosing with the compound.

HAEMATOLOGY
- Males: a significant decrease (p<0.01) of mean corpuscular haemoglobin concentration (MCHC) compared to control was found in the 300 and 1000 mg/kg bw/day dose group, respectively (control: 34.7 ± 0.5%; 100 mg/kg bw/day: 34.4 ± 0.2%; 300 mg/kg bw/day: 33.9 ± 0.4%**; 1000 mg/kg bw/day: 33.9 ± 0.3%**; **p<0.01). No other differences were noted.

CLINICAL CHEMISTRY
- Males: a significant decreased ALP level (p<0.05) compared to control was found in all dosing groups (control: 237 ± 45 U/L; 100 mg/kg bw/day: 200 ± 35 U/L*; 300 mg/kg bw/day: 195 ± 35 U/L*; 1000 mg/kg bw/day: 197 ± 41 U/L*; *p<0.05). A significant decreased glucose level (p<0.05) compared to control was found in the high dose group (control: 152 ± 16 mg/dL; 1000 mg/kg bw/day: 135 ± 14 mg/dL*; *p<0.05). While a significant increase in chloride (p<0.05) was found in the 300 mg/kg bw/day group, a significant decrease in calcium content (p<0.01) and in total protein (p<0.05) was noted in this group. However, all the findings lack a dose-dependency and were regarded as incidental.

ORGAN WEIGHTS
- Males: in 100 mg/kg bw/day males, the actual weight ratio of liver weight compared to control values were increased (p <0.05) . No other significant differences were found in all groups. Thus, this finding lacks a dose-dependency and was regarded as incidental.
- Females: actual kidney weight was significantly reduced (p<0.05) in the 100 mg/kg bw/day group. No other weight changes were noted. Thus, this finding lacks a dose-dependency and was regarded as incidental.

GROSS PATHOLOGY
Males:
- Heart: myocardial degeneration was noted in one animal of the control group and the 1000 mg/kg bw/day group, respectively
- Liver: periportal fatty change of the liver was found in all animals of the control and the high dose group. Focal necrosis was noted in one animal of the high-dose group.
- Spleen: all animals of the control and the high-dose group showed brown pigment deposits of the spleen as well as extramedullary hematopeiosis
- Kidney: while fibrosis was only found in 1/13 animals of the control group, eosinophilic bodies and basophilic tubules in the cortex were noted in animals of both control and 1000 mg/kg bw/day groups
- Adrenal gland: one animal of the high-dose group showed fibrosis
- Testis: atrophy of the seminiferous tubules was observed in two animals of the 1000 mg/kg bw/day dose group, with one animal affected on both sides and one side affected in the other animal. No other abnormalities were noted.
- Epididymis: abnormal sperm granuloma was found in one animal of the control group
- Brain: no abnormal findings noted
- Thymus: no abnormal findings noted
- Bladder: no abnormal findings noted

Females:
- Brain: one animal of the high-dose group showed abnormal mineral deposition in the thalamus
- Liver: focal necrosis and fibrosis was found in one animal of the control group, while one animal of the high-dose group showed only focal necrosis
- Spleen: brown pigmentation and extramedullary hematopeiosis was found in animals of the control and the high-dose group, but no varying degrees of frequency was observed
- Thymus: atrophy and bleeding was observed in animals of both groups, control and high-dose group, respectively
- Kidney: basophilic tubules of the cortex and a dilatation of the renal pelvis was seen in the control and high-dose group
- Adrenal gland: cortical necrosis was observed in one animal of the control group
- Heart: no abnormal findings noted
- Bladder: no abnormal findings noted

Key result

Dose descriptor:

NOAEL

Remarks:

repeared dose toxicity

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no adverse substance-related systemic effects were noted

Critical effects observed:

no

Conclusions:

No deaths were observed in any group, and no changes in general conditions, weight and feeding were observed. After 42 doses there were some decreases noted in the average red blood pigment concentration in males in the 300 mg/kg group, glucose levels decreased significantly in the 1000 mg/kg group. However, since both changes were mild and there were no associated changes in other test items, including pathological examinations, these were considered to be incidental changes and of no toxicological significance. In histopathological examination, two of the animals in the1000 mg/kg group showed very mild microtubule atrophy. As these were very mild and localized, and there were no other changes, these were note considered to be of concern.
The results conclude that under the test conditions, the NOAEL for repeated administration of docosanic acid in regard to toxicity is 1000 mg/kg/day.

Executive summary:

Docosanic acid is a mixture of high-grade saturated fatty acids contained in the constituent fatty acids of carasi oil and rapeseed oil. Industrially, it is distilled and purified after the rapeseed oil is hydrolyzed mainly as a raw material, but it has recently come to be used as a raw material for cosmetics. There is very little information in regard to the toxicity and hazards associated with docosanic acid. A study was conducted to evaluate docosanoic acid. 0 (solvent control), 100, 300 and 1000 mg/kg of docosanoic acid was administered to Sprague-Dawley (Crj:CD) rats, male and female, (13 animals / group), started 2 weeks before mating and 42 days in total for males. For females administration started 2 weeks before mating and continued until 3 days after the start of lactation. Parent animals and infants were examined for effects of repeated administration on the toxicity, fertility, as well as development of the next-generation infants.

No abnormalities or death were observed in any docosanic acid administration group in males. In addition, there was no observed changes in weight and feeding . Autopsy results from histopathological, hematology, hematology and hemobiochemistry tests showed no indications of toxicity or abnormal values attributed to the administration of docosanoic acid.

In females, there were no deaths in any of the docosanic acid administration groups. In addition, changes in general condition, weight, and feeding amount were not observed. In the autopsy and histopathological examination four days after delivery, there were no findings suggesting of effects as a result of docosanic acid administration.

Furthermore, docosanic acid administered in doses up to 1000 mg/kg did not affect mating rate and conception rate. In addition, there were no changes to suggest effects of docosanic acid administration on pregnancy, birth rate, delivery, and baby-care by the mother.

There were no changes in the sex ratio, weight, and survival rate of offspring attributed to the effects of docosanic acid administration. In addition, morphological abnormalities in offspring were not observed in any docosanic acid administration group. These results conclude that under these test conditions, the NOAEL for repeated administration of docosanic acid in regard to toxicity is 1000 mg/kg/day.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

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

The source and target substances are likely to dissociate after administration into metals ions and fatty acids due to the ionic bond between the metal cation and fatty acid ion being disrupted by polar aqueous media. The fatty acid component is not expected to be hazardous as it is potentially exempt from REACH under Annex V. 

Justification for classification or non-classification

No classification is required for calcium dioctanoate based on read across from docosanoic acid administration.