Fatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol

Endpoint summary

Description of key information

Oral (OECD 407), 28 days, rat: 
NOAEL (systemic) = 1450 mg/kg bw/day

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

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

Adequacy of study:

key study

Study period:

Nov. 1992 - Dec. 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

GLP - Guideline study, tested with the source substance CAS 68424-31-7. According to the ECHA guidance document “Practical guide 6: How to report read-across and categories (March 2010)”, the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Species:

rat

Strain:

other: Alpk:APfSD

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Zeneca Pharmaceuticals, Alderly Park, Macclesfield, Cheshire, UK
- Age at study initiation: 28 d
- Weight at study initiation: Males: 148.45 g; Females: 122.6 g
- Housing: sexes separately, five per cage, Cages had measurements of 26.5x50.0x20.0 cm and were constructed of stainless steel mesh with one solid side.
- Diet: ad libitum (Based on CT1 diet; Special Diets Services Limited, Witham, Essex, UK
- Water: ad libitum
- Acclimation period: approx. 1 week


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23
- Humidity (%): 45-65 (71 at one occasion)
- Air changes (per hr): 25-30
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: November 1992 To: December 1992

Route of administration:

oral: feed

Vehicle:

other: ethyl acetate

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: All diet were based on CT1 diet (Special Diets Services Limited, Witham, Essex, UK). They were prepared by grinding the appropriate amount of test substance with 1 kg of milled CT1 diet. This premix was then added to 14 kg of diet and mixed thoroughly with a Pharma Blender Model PMA 100S (T K Filder).

DIET PREPARATION
- Rate of preparation of diet (frequency): 15 kg batches
- Mixing appropriate amounts with (Type of food): CT1 diet (Special Diets Services Limited, Witham, Essex, UK)
- Storage temperature of food: - 20°C, stored at RT for usage up to 14 days

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Chemical stability was determined for diets over a period of 5 weeks following storage at RT or at -20°C.
Samples were extracted by chemical shaking with ethyl acetate. The supernatant was diluted with ethyl acetate to give solutions containing appropriate concentrations of the test substance. Extracts were analysed by gas chromatography using flame ionisation detection. The extract concentration was calculated by reference to data from a standard containing a known concentration.

Duration of treatment / exposure:

daily

Frequency of treatment:

28 d

Remarks:

Doses / Concentrations:
0 ppm, 1000 ppm, 5000 ppm, 12500 ppm
Basis:
nominal in diet

Remarks:

Doses / Concentrations:
112 mg/kg/d, 562 mg/kg/d, 1450 mg/kg/d
Basis:
other: actual ingested for males

Remarks:

Doses / Concentrations:
119 mg/kg/d, 586 mg/kg/d, 1613 mg/kg/d
Basis:
other: actual ingested for females

No. of animals per sex per dose:

5

Control animals:

yes

Details on study design:

- Dose selection rationale: Based on results of preliminary feeding studies
- Rationale for animal assignment (if not random): The sexes were randomised separately.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Daily
- Cage side observations checked: changes in clinical condition and behaviour and significant changes were recorded.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: on days 8, 15, 22, 29
- observations included, but were not limited to the assessment of autonomic function (e.g. lachrymation, salivation, piloerection, exophthalmus, urination, defecation, pupillary function, ptosis), description, incidence and severity of any convulsions, tremors, abnormal motor function, alteration in respiration, reactivity to stimuli, changes in the level of arousal, sensorimotor responses

BODY WEIGHT: Yes, measurement in replicate order immediately before feeding and at the same day once a week until termination.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Food consumption for each animal determined and mean daily diet consumption calculated as mg food/kg body weight: Yes, on a weekly basis
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: 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: At termination, all rats were bled by cardiac puncture and samples were collected. Parameters determined: Hemoglobin, red cell count, haematocrit, mean cell volume, mean cell haemoglobin, mean cell haemoglobin concentration, platelet count, white blood cell count, neutrophil count, lymphocyte count, monocyte count, eosinophil count, prothrombin time and kaolin-cephalin time

CLINICAL CHEMISTRY: Yes, At termination, all rats were bled by cardiac puncture and samples were collected. Parameters determined: Albumin, total protein, cholesterol, triglycerides, urea, creatinine, glucose, total bilirubin and alkaline phosphatase, plasma gamma-glutamyl transferase, plasma alanine aminotransferase, plasma aspartate aminotransferase, plasma creatine kinase, plasma sodium, plasma potassium, plasma chloride, plasma calcium and plasma phosphorus

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: on days 8, 15, 22, 29
- Dose groups that were examined: All
- Battery of functions tested: sensory activity / grip strength

Sacrifice and pathology:

GROSS PATHOLOGY: Yes

HISTOPATHOLOGY: Yes (Adrenals, Aorta, Bladder, Bone and Bone marrow (femur), Brain, Caecum, Colon, Cervical lymph node, Cervix, Colon, Duodenum, Epididymis, Eye and harderian gland, Heart, Ileum, Jejunum, Kidney, Liver, Lungs, Mammary gland, Mesenteric lymph node, Nasal passages, Oesophagus, Oral cavity, Ovaries, Pancreas, Parathyroid glad, Pituary gland, Prostate gland, Rectum, Salivary glands, Sciatic nerve, Seminal vesicles, Skin, Spinal chord, Spleen, Sternum, Stomach, Testes, Thymus, Thyroid gland, Trachea, Uterus, Voluntary muscle)

Statistics:

Bodyweights were considered by analysis of covariance on initial body weight, separately for males and females.
Time to tail flick and fore and hindlimb grip strength at weeks 2, 3, 4 and 5 were considered by analysis of variance, separately for both sexes.
Haematological and clinical blood parameters were considered by analysis of variance.
Organ weights were considered by analysis of variance and covariance on final body weight separately for both sexes.

Details on results:

DIET ANALYSIS:
All diets prepared were found to be within 4 % of the target concentration. The homogeneity of the test material in the diet, determined at 1000 and 12500 ppm inclusion levels was within 2 % of the overall mean concentration for both levels. Chemical stability of the test material , assessed at the 1000 and 12500 ppm inclusion levels stored at room temperature or at -20 °C was satisfactory over the period of use.
Dose rates (based on nominal dietary levels) were highest at the start of the study and declined rapidly during the period of rapid growth to week 4.

MORTALITY
There were no mortalities.

FUNCTIONAL OBSERVATION BATTERY
There were no mortalities.
A slightly reduced splay reflex was observed in one female on the 1000 ppm group (on days 29 and 30), one male in the 5000 ppm group (on day 29) and one male in the 12500 ppm group (on day 29). As isolated observations, these were considered to be incidental to treatment.
There were no differences in time to tail flick in either sex which could be attributed to treatment. The statistically significant increase in time to response observed on day 22 for males (5000 ppm) and day 8 for females (1000 ppm) were considered to be incidental to treatment in the absence of similar changes at higher dose levels.
There was no evidence of any treatment related effects on forelimb or hindlimb grip strength.
Any other statistically significant changes were considered spurious and unrelated to treatment with the test material.

BODY WEIGHT AND WEIGHT GAIN
There were no statistically significant effects on body weight and all final bodyweights were within 3% of the respective controls, after adjusting for initial weight differences.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Food consumption in all treated groups remained similar to, or exceeded that, of the respective control group throughout the study.

HAEMATOLOGY
There were statistical significant reductions in haemoglobin and haematocrit at 12500 ppm in male rats. Statistically significant reductions in haemoglobin and haematocrit were seen in females at 1000 and 5000 ppm and in white blood cell count at 1000 ppm. In the absence of a coherent dose-response relationship, these differences were considered incidental to treatment.
Any other statistically significant changes were considered spurious and unrelated to treatment with the test material.

CLINICAL CHEMISTRY
There were minor reductions in plasma cholesterol, triglyceride and total protein levels and plasma alanine transferase activities in males at 12500 ppm compared to controls. Any other statistically significant changes were considered spurious and unrelated to treatment with the test material.
ORGAN WEIGHTS
Kidney weights adjusted for body weight were statistically significant increased in males at 5000 and 12500 ppm. All the females in the treatment groups had slightly raised kidney weights compared to control, but none achieved statistical significance, and there was no evidence of a coherent dose response relationship.
Liver weights adjusted for body weight were statistically significant increased in both sexes at 12500 ppm and in males at 5000 ppm.
Any other statistically significant changes were considered spurious and unrelated to treatment with the test material.

PATHOLOGY:
Macroscopic findings:
No treatment-related macroscopic findings were apparent at the end of the study.
Microscopic findings:
Treatment related findings were present in the kidney of male rats from all dose groups. In the 5000 and 12500 ppm dose group these comprised increased tubular hyaline droplet formation and tubular basophilia in all animals, and granular cast formation in four of the 5000 ppm animals and all of the 12500 ppm animals; the latter occurring at the cortico-medullary injection. In the 1000 ppm group, increased renal hyaline droplet formation and/or tubular basophilia were seen, but not granular cast formation.
In the liver, there was minimal hepatocyte hypertrophy in four out of five male rats in the 12500 ppm group.

The increased kidney weights and microscopic findings of renal tubular basophilia, granular cast formation and increased hyaline droplet formation present in male rats at 5000 and 10000 ppm are clearly treatment related. These findings are consistent with the well characterized light hydrocarbon nephropathy described for male rats, following to a variety of chemicals including light hydrocarbons such as unleaded gasoline and trimethyl pentane. The characteristics include an increased accumulation of hyaline droplets in male rat kidneys, the main constituent of which is alpha 2µ-globulin (Alden et al. Adv. Modern Environ Toxicol 7: 107-120 (1984); Stonard et al. Renal Heterogeneity and Target Cell Toxicity. Bach PH and Lock EA Eds, John Wiley and Sons (1985)). It is widely accepted that this phenomenon is specific to male rat and as such appears to have no relevance for man (Swenberg et al. Toxicol and App. Pharmacol. 97: 35-46 (1989)).

Dose descriptor:

NOAEL

Effect level:

12 500 ppm

Based on:

test mat.

Sex:

female

Basis for effect level:

other: No effects observed in female rats

Dose descriptor:

NOAEL

Effect level:

1 613 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: No effects observed in female rats

Dose descriptor:

NOAEL

Effect level:

12 500 ppm

Based on:

test mat.

Sex:

male

Basis for effect level:

other: Treatment related histopathological changes and changes in kidney and liver weight in male rats at 5000 ppm and above are considered species-specific effects which are not relevant for humans and therefore not considered for NOAEL determination.

Dose descriptor:

NOAEL

Effect level:

1 450 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: Treatment related histopathological changes and changes in kidney and liver weight in male rats at 5000 ppm and above are considered species-specific effects which are not relevant for humans and therefore not considered for NOAEL determination.

Critical effects observed:

not specified

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 450 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The available information comprises an adequate and reliable study (Klimisch score 2) from a reference substance with similar structure and intrinsic properties. Read-across is justified based on common functional groups, common precursors/breakdown products and similarities in physicochemical and toxicological properties (refer to endpoint discussion for further details). The selected study is thus sufficient to fulfil the standard information requirements set out in Annex VIII, 8.5, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006.

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

Justification for grouping of substances and read-across

There are no data available for repeated dose toxicity of Fatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol (CAS 92113-48-9). In order to fulfil the standard information requirements set out in Annex IX, 8.6.2, in accordance with Annex XI, 1.5, of Regulation (EC) No 1907/2006, read-across from a structurally related substance was conducted.

In accordance with Article 13 (1) of Regulation (EC) No 1907/2006, "information on intrinsic properties of substances may be generated by means other than tests, provided that the conditions set out in Annex XI are met.” In particular, information shall be generated whenever possible by means other than vertebrate animal tests, which includes the use of information from structurally related substances (grouping or read-across).

Having regard to the general rules for grouping of substances and read-across approach laid down in Annex XI, 1.5, of Regulation (EC) No 1907/2006, whereby physicochemical, toxicological and ecotoxicological properties may be predicted from data for reference substance(s) by interpolation to other substances on the basis of structural similarity, Fatty acids, C5-10, esters with pentaerythritol (CAS 68424-31-7) is selected as source substance for assessment of repeated dose toxicity.

Repeated dose toxicity

CAS	92113-48-9 (a)	68424-31-7 (b)
Chemical name	Fatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol	Fatty acids, C5-10, esters with pentaerythritol
MW	512.8 – 975.5	472.62 - 753.14 g/mol
Repeated dose toxicity, oral	RA: CAS 68424-31-7	Experimental result: NOAEL(subacute, rat, m) = 1450 mg/kg bw/day NOAEL (subacute, rat, f) = 1613 mg/kg bw/day
Repeated dose toxicity, inhalation	--	--
Repeated dose toxicity, dermal	--	--

(a) The substance subject to the REACh Phase-in registration deadline of 31 May 2013 is indicated in bold font. Only for this substance a full set of experimental results and/or read-across is given.

(b) Reference (read-across) substances are indicated in normal font. Lack of data for a given endpoint is indicated by “--“.

The above mentioned substances are considered to be similar on the basis of the similarities in structure, properties and/or activities. The available endpoint information is used to predict the same endpoint for Fatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol (CAS 92113-48-9).

A detailed analogue approach justification is provided in the technical dossier (see IUCLID Section 13).

Furthermore, based on exposure considerations no further data for the endpoints “Repeated dose toxicity” and “Toxicity to reproduction” were included in the dossier. In order to put the main focus on human health, a very conservative approach was followed. The exposure assessment is based on the reproductive toxicity of 2-ethylhexanoic acid, which is assumed to be the most sensitive endpoint (LOEL = 100 mg/kg bw/day for reproductive toxicity). No further adverse effects after repeated exposure of the test substance itself is supposed. This is supported by a subchronic toxicity study (Brammer, 1993) with the analogue substance Fatty acids, C5-10, esters with pentaerythritol (CAS 68424-31-7), in which no adverse effects were found, revealing NOAEL values of 1450 and 1613 mg/kg bw (highest dose tested) in male and female rats, respectively.

 

Discussion

Repeated dose toxicity

A 28-day GLP-compliant study was conducted with Fatty acids, C5-10, esters with pentaerythritol (CAS 68424-31-7) according to OECD Guideline 407 (Brammer, 1993). Groups of male and female rats (5 per sex and dose) were orally exposed to 1000 ppm, 5000 ppm, 12500 ppm in food (corresponding to 112, 562, and 1450 mg/kg bw/day for male and 119, 586, and 1613 mg/kg bw/day for female rats, respectively) for 28 consecutive days. There were no toxicologically significant effects on body weight, food consumption and clinical condition up to and including the highest dose level. Changes in some clinical chemistry and red cell-related parameters were observed in male rats at 12500 ppm, but these were minor and considered not to be of toxicological significance. There were no clinical signs indicative of neurological dysfunction in any of the treatment groups, nor was there any evidence of neuropathological changes in the brains of the 12500 ppm group. A minimal hepatocyte hypertrophy, present in males in the 12500 ppm group, was considered to be evidence of an adaptive response. Microscopic examination of the kidneys from male animals from all dose groups revealed an increase in hyaline droplet formation (the main constituent of which is alpha-2µ-globulin) and tubular basophilia; this phenomenon is widely accepted to be specific to the male rat and as such is considered to have no relevance to humans. A NOAEL of 1450 and 1613 mg/kg/day could be identified for male and female rats, respectively.

Conclusion

No adverse effects were observed after a 28-day treatment of rats with Fatty acids, C5-10, esters with pentaerythritol (CAS 68424-31-7) in diet and a NOAEL of 1450 (male) and 1613 mg/kg/day (female) was identified, respectively. In conclusion, based on read-across data from an analogue substance, Fatty acids, C14-18 and C16-18-unsatd., mixed esters with castor oil, castor oil fatty acids, 2-ethylhexanoic acid and 2,2-bis(hydroxymethyl)-1-butanol is expected not to induce adverse effects after repeated oral exposure.

In addition, a substance-tailored exposure-driven testing was followed for the hazard assessment of repeated dose toxicity. No significant exposure is expected throughout all relevant exposure scenarios according to Annex XI, section 3.2(a) (i), therefore additional testing for repeated dose toxicity is omitted in accordance with Annex VIII column 2 section 8.6.1. The justification is based on an exposure assessment in accordance with section 5 of Annex I.

Further details are given in the endpoint itself, as well as in the chapter "Toxicological information" and in chapter 9 and 10 of the CSR.

Justification for selection of repeated dose toxicity via oral route - systemic effects endpoint:
Hazard assessment is conducted by means of read-across from a structural analogue. The selected study is the most adequate and reliable study based on the identified similarities in structure and intrinsic properties between source and target substance and overall assessment of quality, duration and dose descriptor level (refer to the endpoint discussion for further details).

Justification for classification or non-classification

Based on read-across from a structurally similar substance, the available data on repeated dose toxicity do not meet the classification criteria according to Regulation (EC) 1272/2008 or Directive 67/548/EEC, and are therefore conclusive but not sufficient for classification.