Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Administrative data

Endpoint:
immunotoxicity: oral
Remarks:
other: OECD 443
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
02 Feb 2015 - 03 Dec 2015
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP Guideline Study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report date:
2016

Materials and methods

GLP compliance:
yes

Test material

Constituent 1
Reference substance name:
2-ethylhexanoic acid
EC Number:
205-743-6
EC Name:
2-ethylhexanoic acid
Test material form:
other: liquid
Details on test material:
- Name of test material (as cited in study report): 2-Ethylhexanoic acid
- Molecular formula (if other than submission substance): C8H16O2
- Molecular weight (if other than submission substance): 144.21
- Physical state: Liquid, colourless to yellow
- Analytical purity: 99.6%
- Lot/batch No.: 15667956P0
- Expiration date of the lot/batch: 25 July 2016
- Storage condition of test material: ambient temperature

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Harlan, Horst, the Netherlands
- Age at study initiation: (P) 9 weeks females; 10 weeks (males)
- Weight at study initiation: (P) Males: 373.39 - 375.26 g; Females: 200.68 - 203.17 g;
- Housing: During the premating period, the animals were, as far as possible, housed in groups of 4/sex. For mating, one male and one female
were housed together. Mated females were housed individually in macrolon cages, which were placed in another cage rack.After allocation to the
cohorts at weaning on PN day 21, the F1 animals were housed in groups of 5/sex/cage, except for the animals of cohort 2B that were housed per
lot (animals born on the same date) per dosing group until sacrifice on approximately PN day 22.
- Diet: ad libitum; cereal-based rodent diet (VRF-1) SDS, Witham, England
- Water: ad libitum
- Acclimation period:

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24
- Humidity (%): 45-65%; due to technical reasons, in animal room 5.1.08 of Cohort 1B animals, the relative humidity was higher than 65% from
29 June 2015 to 6 July 2015
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:
oral: feed
Details on exposure:
PREPARATION OF DOSING SOLUTIONS:
- The intake of the test item per kg body weight per day was calculated from the nominal dietary concentration, the feed consumption and the body
weight at the end of the pertaining period

DIET PREPARATION
- Rate of preparation of diet (frequency)::The diets were mixed in a mechanical blender. Fresh batches of the experimental diets were prepared once
per month and stored in a freezer (<-18°C) in plastic bags in portions sufficient for three or more days.
Duration of treatment / exposure:
Male animals received the test item via the diet during a 2-week premating period, during mating and up to and including the day of sacrifice.
Female animals were fed the diets during a 2-week premating period, and during mating, gestation and lactation and up to and including the day ofsacrifice.
Animals of Cohort 1B received the diets from weaning up to and including the day of sacrifice.
Frequency of treatment:
ad libitum ( daily, 7 days per week)
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
0, 80, 250, 800 mg/kg bw/day
Basis:
other: anticipated dose of test item
Remarks:
Doses / Concentrations:
0, 1231, 3845, 12308 mg/kg
Basis:
other: dietary level of test item
No. of animals per sex per dose:
Cohort 3: One male or one female pup per litter was selected (10/sex/group) and additionally, 6 pups/sex/control group as positive control group for the KLH-assay.

Examinations

Observations and clinical examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
Each animal was observed daily in the morning hours by cage-side observations and, ifnecessary, handled to detect signs of toxicity. All cages were checked again in the afternoon for dead or moribund animals. All abnormalities, signs of ill health or reactions to treatment were recorded. Any animal showing signs of severe debility or intoxication, particularly if death appears imminent, was humanely killed to prevent loss of tissues by cannibalism or autolytic degeneration

DETAILED CLINICAL OBSERVATIONS: Yes
Once weekly all animals were subjected to detailed clinical observations, e.g. during weighing.

BODY WEIGHT: Yes / No / No data
Body weights of male and female animals were recorded weekly. Additionally body weight was recorded on the day of attainment of vaginal patency or
balano-preputial separation.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
The food in the feeders was refreshed twice per week. Except for during the mating period, the food consumption was measured per cage over the
sameperiods as the body weight was measured. The results are expressed in g per animal per day.
Intake of the test item
The intake of the test item per kg body weight per day was calculated from the nominal dietary concentration, the feed consumption and the body
weight at the end of the pertaining period.

OTHER:
Sexual maturation
The following landmarks for sexual maturation were recorded in F1 animals in cohort 3:
- males: preputial separation from postnatal day 39 onwards
- females: vaginal opening from postnatal day 31 onwards
Daily checks were discontinued after 95% of the animals had reached sexual maturation. At the day the animals were scored positive for preputial
separation or vaginal opening, the body weight was measured.
KLH immunization
On postnatal day 56 (± 3 days) all Cohort 3 animals of each group were immunized with an intravenous injection of 600 μg keyhole limpet
hemocyanin (KLH) to evaluate T-cell dependent antibody response (TDAR). As a positive control, aiming to induce reduction of the KLHspecific
TDAR, an extra group of 6 male and 6 female animals were treated daily with 20 mg/kg Cyclosporine A via oral gavage, starting one week before
KLH immunization until, but not including, the day of sacrifice.
Terminal body weight
Terminal body weight was determined for all Cohort 3 animals prior to necropsy

Sacrifice and pathology:
Gross necropsy and histology of Cohort 3
All surviving male and female parent animals were sacrificed by exsanguination from the abdominal aorta whilst under CO2/O2 anaesthesia at
necropsy and then examined grossly for pathological changes.
Samples of the following tissues and organs of all parent animals were preserved in a neutral aqueous phosphate-buffered 4% solution of
formaldehyde: Spleen , Thymus
Specific cell-mediated immunity:
Determination of T-cell dependent antibody responses
Blood samples were collected during necropsy. After clotting serum was prepared by centrifugation. The prepared serum aliquots were stored
at ≤-18 oC until further use. To evaluate the T-cell dependent antibody responses elicited by the subcutaneous KLH immunization, the titre of
KLH-specific IgM antibodies in the sera was determined with an ELISA-based method.
Statistics:
Tests were generally performed as two-sided tests with results taken as significant where the probability of the results is p<0.05 (*) or p<0.01 (**).

Results and discussion

Results of examinations

Details on results:
Mortalities and clinical observations
Male animals 043-03 of the positive control group was found dead on day 24 (the first day of oral treatment with Cyclosporine A). A clear fluid wasobserved around nose and mouth. At necropsy, the lungs were dark red and showed incomplete collapse. Possibly, the lungs were red due to a
dosing error of Cyclosporine of Cyclosporine was eructated from the stomach. Daily cage-side observations and the weekly detailed clinical
observations at the day of weighing showed only common findings in rats of the strain and age or occurred as individual fortuitous findings.
The distribution of the findings was equally amongst the various groups or occurred in only one of a few animals. Therefore, these findings were
not considered to be related to treatment.
Body weight and body weight changes
Mean body weights of the male animals of the high-dose group of Cohort 3 were lower than the mean body weights of the control group during
the entire period, reaching the level of statistical significance on days 14, 21, 28 and 35. On day 35, also the mean body weights of the males of theCyclosporine A positive control group were statistically significantly decreasedas compared to the control group. Mean body weight changes of
the male animals of the low-dose (from days 7-14), high- (entire period) and positive control group (from days 21 -28 and 28-35) were
statistically significantly decreased as compared to the control group. Except for the mean body weights and mean body weight changes of the
females animals of the Cyclosporine positive control group which were statistically significantly increased on day 35 and from days 28-35,
respectively, mean body weights and mean body weight changes of the females animals of Cohort 3 were comparable amongst the various groups.
Food consumption
In male animals of the Cyclosporine positive control group of Cohort 3, food consumption (expressed as g/animals/day) was statistically
significantly decreased from day 28-25. In the female animals of the low-dose and high-dose groups, food consumption was increased from
days 7-14 and from 7-14 and 28-35, respectively.
Intake of test item
The mean test item intake of male animals ranged between 107-181, 334-569 and 1072-1810 mg/kg body weight/day for the low-, mid- and
high-dose groups, respectively The mean test item intake of female animals ranged between 110-183, 323-550 and 1032- 1736 mg/kg body
weight/day for the low-, mid- and high-dose groups, respectively.
Organ weights of Cohort 3
The final body weights of the male animals of the high-dose group and of the Cyclosporine positive control group were statistically significantly
decreased as compared to the final body weights of the control animals. In these groups, also the absolute weight of the spleen was
statistically significantly decreased with approximately 15% and 22%, respectively. In the male animals of the positive control group, the absolute
weight of the thymus was statistically significantly decreased (approximately 28%). No effects were observed in relative weights of the spleen and
thymus amongst the various groups. In the female animals, the final body weights of the positive control group were statistically
significantly increased as compared to the mean final body weights of the control animals. No statistically significant effects were observed in
absolute- and relative weights of the spleen and thymus amongst the groups.
KLH immunization
Details of the KLH-immunization test are described in Annex10. In brief, the positive control Cyclosporine A induced a statistically significant
reduction of the KLH-specific IgM antibody response, in both male and female rats. In contrast, a low-, medium- or high dose of
2-Ethylhexanoic acid did not alter the KLH-specific IgM antibody levels in male or female rats, as compared to the vehicle control animals.
Macroscopic observations
Besides animal 0430-3 that was found dead, macroscopic observations at necropsy of the remaining animals revealed no treatment-related
abnormalities. The findings were considered unremarkable and part of the background pathology of rats of this strain and age.

Applicant's summary and conclusion

Conclusions:
There were no effects of the test item on (developmental) immune toxicity parameters.