Reaction mass of tridecanal and 2-methyldodecanal and pentadecanal and 2-methyltetradecanal

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2011-01-13 to 2011-12-20

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study and GLP conform

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2011

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EPA OPPTS 870.3650

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-methyldodecanal; 2-methyltetradecanal; pentadecanal; tridecanal

EC Number:

931-038-4

Molecular formula:

Not applicable - Multi constituent

IUPAC Name:

2-methyldodecanal; 2-methyltetradecanal; pentadecanal; tridecanal

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Harlan Laboratories, B.V. Kreuzelweg 53 5961 NM Horst / Netherlands
- Age at study initiation: 11 weeks
- Weight at study initiation: males 309 to 341 g; females 188 to 225 g
- Fasting period before study: no
- Housing: singly in Makrolon type-3 cages with wire mesh tops and standard softwood bedding
- Diet: pelleted standard diet (Kliba Nafag 3433 rodent maintenance diet) ad libitum
- Water: tap water ad libitum
- Acclimation period: minimum 5 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3 °C
- Humidity: 30-70%
- Air changes (per hr): 10-15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

peanut oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:

- Rate of dose formulation preparation: weekly
- Separate formulations were prepared for each dose level
- Homogeneity was maintained during the daily administration period using a magnetic stirrer
- Storage conditions: at room temperature (20 ± 5 °C) in the dark

VEHICLE
- Justification for use and choice of vehicle (if other than water): low water solubility of the test item
- Concentration in vehicle: up to 25, 75, and 250 g/L
- Amount of vehicle (if gavage): 4 mL/kg
- Lot/batch no. (if required): 280160017
- Provider: Carl Roth, Karlsruhe, Germany

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

GC-FID using calabrication curve; samples were analysed in duplicate.

Duration of treatment / exposure:

Males: 4 weeks (2 weeks pre-pairing, 2 weeks pairing period)
Females: 7 weeks (2 weeks pre-pairing, 2 weeks pairing period, 3 weeks gestation)

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 300, 1000 mg/kg/day
Basis:
actual ingested

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: based on the results of a range-finding study

Positive control:

not required

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule:
-viability/mortaility: twice daily
-clinical signs: once daily
- Cage side observations checked were included

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: prior to the first treatment, weekly thereafter

BODY WEIGHT: Yes
- Time schedule for examinations: daily from treatment start to necropsy

FOOD CONSUMPTION:
- Food consumption for each animal determined (not during pairing): 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

WATER CONSUMPTION: Not required

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood:
males: the day before scheduled necropsy
females: day 5 post partum
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes
- How many animals: 5 per sex
- Parameters checked cover and exceed parameters listed in OECD TG 422.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood:
males: the day before scheduled necropsy
females: day 5 post partum
- Animals fasted: Yes
- How many animals: 5 per sex
- Parameters checked cover and exceed parameters listed in OECD TG 422.

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: at the end of the treatment period.
-- Males: shortly before scheduled sacrifice
-- Females on day 3 or 4 post partum
- Dose groups that were examined: 5 male and female rats from each dose group
- Battery of functions tested: sensory activity / grip strength / motor activity /

Sacrifice and pathology:

GROSS PATHOLOGY: Yes.
All parent animals and pups were examined

HISTOPATHOLOGY: Yes
All organs and tissues of the control and high-dose parent animals were examined. The same applies to all occurring gross lesions or animals that died spontaneously. Tissues preserved include male (prostate, testes, seminal vesicles, epididymides) and female (ovaries, uterus with vagina) reproductive organs.

Other examinations:

Special emphasis was made on the stages of spermatogenesis and histopathology of interstitial cell structure.

Statistics:

The following methods were used to analyse food consumption, body weights, and reproduction data:
- calculation of means and standard deviations.
- Dunnett-test (many to one t-test) based on a pooled variance estimate was applied if the variables could be assumed to follow a normal distribution for the comparison of the treated groups and the control groups for each sex.
- Steel-test (many-one rank test) was applied instead of the Dunnett-test when the data could not be assumed to follow a normal distribution.
- Fisher's exact-test was applied if the variables could be dichotomized without loss of information.

Results and discussion

Results of examinations

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:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Description (incidence and severity):

increased liver weight at 1000 mg/kg/day without histopathological correlate was not considered to be adverse.

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY
All animals survived, and there were no test item-related clinical signs at any dose level.

BODY WEIGHT AND WEIGHT GAIN
No effects on body weight or body weight gain of males or females which were considered to be related to treatment were noted at any dose level.

FOOD CONSUMPTION
Food consumption was unchanged.

HAEMATOLOGY
There were no effects on haematology parameters in males or females which were considered to be related to treatment.

CLINICAL CHEMISTRY
No effects on clinical biochemistry parameters, which were considered to be test item-related, were noted at any dose level in males or females.

NEUROBEHAVIOUR
FOB (home cage observations; observation in the hand; open filed observations; cf. Appendix V, p 424): No test item-related effects were noted during functional observational battery in males or females at any dose level. The following observations were noted for individual animals or did not follow a dose dependency pattern and therefore were considered not to be test item-related: vocalization in one male (no. 11) at the dose level of 100 mg/kg bw/day, decreased landing foot splay distance in males at the dose level of 100 mg/kg bw/day, lifting and increased rearings in one female (no. 51) at the dose level of 100 mg/kg bw/day, decreased rearings and increased number of faeces balls in one females (no. 66) at the dose level of 300 mg/kg bw/day. Chromodacryorrhea in female no. 64 was confirmed. No further observations were noted in males or females at any dose level.
Grip strength: no changes observed in treated males (p 81) and females (p 85) at any dose.
Locomotor activity of males (p 88) and females (p 90) not significantly different from controls at any dose.

ORGAN WEIGHTS
No significant absolute and relative organ weight changes in males and females noted at any dose. This includes male and female reproductive organs.
Exceptions:
- Liver: absolute and relative liver weight was statistically significantly increased at 1000 mg/kg bw and day. In the absence of findings indicating liver injury this was regarded to be most probably a result of metabolic adaptation and not adverse.
- Heart: statistically significantly higher absolute and relative heart weights were seen in males. However, the difference to the control value was minor. Further, the mean heart weights were in the range of historical control values, and there was no clear dose relationship. Therefore, this effect was not considered to be treatment-related.
- Thymus: in females at 100 mg/kg and day, statistically significantly higher absolute and relative thymus weights were noted. This effect was not seen in higher dose groups, hence this was not considered to be related to treatment.

GROSS PATHOLOGY
No test item-related findings were noted during necropsy of males and females at any dose level.

HISTOPATHOLOGY: NON-NEOPLASTIC
Treatment with the test item led to an increased incidence of centrilobular to diffuse hepatocellular hypertrophy of minimal severity in males and females at the dose levels of 1000 and 300 mg/kg bw/day. This finding was noted in one male in the control group and 2 males at each dose level 300 and 1000 mg/kg bw/day and one and three females at the dose levels of 300 and 1000 mg/kg bw/day, respectively. In the absence of any further indicators of liver injury, hepatocellular hypertrophy was considered to be of metabolic nature.

Other findings were within the range of normal background lesions which may be recorded in animals of this strain and age. This includes findings in male and female reproductive organs.

Effect levels

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

n/i-C13-C15 aldehyde was tested in a vaild OECD TG 422 oral gavage study in rats. The subacute NOAEL value was 1000 mg/kg bw and day in parental animals.

Executive summary:

n/i-C13 -C15 aldehyde was tested in an OECD TG 422 oral gavage study in rats under GLP conditions. The test item was administered to 10 male and female rats over approximately 28 days suspended in peanut oil as vehicle at dosages of 100, 300, and 1000 mg/kg body weight/day, and controls received the vehicle only. The dose volume was 4 mL/kg bw and day throughout the study. The test substance was administered to male rats for at least 28 days and to female rats for 14 days prior to pairing, through the pairing and gestation periods until the F1 generation reached day 4 post partum.  

 

All animals survived the scheduled study period. No test item-related clinical signs or findings during functional observational battery or locomotor activity were noted in males or females at any dose level. Food consumption, body weights and body weight gain were not affected in males or females up to the dose level of 1000 mg/kg bw/day. Hematology and clinical biochemistry parameters remained unchanged up to and including the highest dose level applied in this study. Upon termination of the parental generation, in animals of both genders higher liver weights were found at the dose level of 1000 mg/kg bw/day as well as an incidence of centrilobular to diffuse hepatocellular hypertrophy was found in males of dose groups 3 treated with 300 mg/kg and both genders of dose group 4 treated with 1000mg/kg. In the absence of any further finding indicating liver injury, these increased weights as well as histopathological change in the liver were considered to be most probably a result of metabolic adaptation (metabolism of the test substance) and not adverse. Based on the above the subacute NOAEL for general toxicity in male and female rats was considered to be 1000 mg/kg bw/day. 

The study is considered to be valid and suitable for assessment.

 

Information on reproduction and developmental toxicity is reported in sections 7.8.1 and 7.8.2, respectively.