Alkenes, C20-24 .alpha.-

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002-06-11 to 2002-10-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This study is classified as reliable without restrictions because the study was compliant with GLPs set forth by OECD [ENV/MC/CHEM(98)17], and the study design was based on OECD guideline 422. The study is well documented and scientifically acceptable.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

A urinalysis was not conducted.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Alkene, C6

IUPAC Name:

Alkene, C6

Constituent 2

Reference substance name:

Alkenes, C6-

EC Number:

271-208-9

EC Name:

Alkenes, C6-

Cas Number:

68526-52-3

IUPAC Name:

hex-3-ene

Details on test material:

- Name of test material (as cited in study report): C6-Olefin/Hexene
- Substance type: Alkene 6
- Physical state: Liquid
- Analytical purity: 85.31%
- Impurities (identity and concentrations): Water (0.0065%), C4 and lights (0.12%), C5 hydrocarbon (13.06%), and C7 hydrocarbon (1.52%)
- Lot/batch No.: None provided
- Stability under test conditions: The compound is stable under the test conditions.
- Storage condition of test material: In a non-flammable cabinet at ambient conditions.

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Portage, Michigan and Raleigh, North Carolina
- Age at study initiation: approximately 11 weeks
- Weight at study initiation: Males: 237 to 296 grams; Females: 170 to 226 grams; weights were obtained on the day after receipt
- Housing: Individually except during mating
- Diet (e.g. ad libitum): Ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: 17 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 18 to 26
- Humidity (%): 41% to 53%
- Air changes (per hr): 10 to 15
- Photoperiod (hrs dark / hrs light): 12 hours dark/12 hours light

IN-LIFE DATES: From: 2002-06-11 To: 2002-08-08

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: A specific amount of test compound was weighed into a precalibrated beaker. A sufficient amount of corn oil was added to the beaker to achieve the desired concentration and the solution was stirred for 30 minutes. The dose formulations were prepared twice during the first week and weekly thereafter. Dose solutions were stirred continuously prior to and during dosing.


VEHICLE
- Justification for use and choice of vehicle (if other than water): None provided
- Concentration in vehicle: 0, 20, 100, 200 mg/mL
- Amount of vehicle (if gavage): 5 mL/kg
- Lot/batch no. (if required): RE1547
- Purity: Not reported

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The test solution was determined to be homogeneous and stable for at least 14 days. The first, third, fifth, seventh, and final dose preparation were tested for concentration verification. The concentrations were found to be within acceptable ranges and were within 15% of the nominal concentration.

Duration of treatment / exposure:

4 weeks

Frequency of treatment:

Daily

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 100, 500, or 1000 mg/kg/day
Basis:
actual ingested

No. of animals per sex per dose:

Twelve animals per sex per dose

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The doses were selected to produce a graded response, but there was no rationale as to why these specific doses were selected.
- Rationale for animal assignment (if not random): Animals were randomly assigned based on body weights.

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Once daily
- Cage side observations checked for overt signs of toxicity.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Weekly and on day of sacrifice

BODY WEIGHT: Yes
- Time schedule for examinations: Days 0, 3, 7, 12, 16, 20, 23, 27, 30 and the day of sacrifice (day 34 for males and day 38 for females)

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

FOOD EFFICIENCY: No

WATER CONSUMPTION: No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: At sacrifice
- Anaesthetic used for blood collection: Yes (light isoflurane)
- Animals fasted: Yes
- How many animals: All surviving animals
- Parameters checked in table 1 were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At sacrifice
- Animals fasted: Yes
- How many animals: All surviving animals
- Parameters checked in table 2 were examined.

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: Weekly
- Dose groups that were examined: All groups
- Battery of functions tested: An abbreviated functional observational battery test was conducted weekly and a full test was conducted on day 28. Motor activity was also measured.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes (see table 3)

Other examinations:

The following organs were weighed: adrenals, brain, heart, kidneys, liver, spleen, epididymides, testes, and thymus.

Statistics:

A one-way analysis of variance followed by Tukey-Kramel test or Dunnett's test was used on continuous data. Organ weight data was first checked for homogeneity with Levene's test. Non-parametric organ weight was analyzed using a Kruskal-Wallis followed by Dunn's test. Categorical data was analyzed using Fischer's exact test or RxC chi-square test followed by a Fischer's exact test.

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:

effects observed, treatment-related

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: There were no treatment-related mortalities. High-dose males and females had occasional post dosing salivation. There were no other clinical signs of toxicity.


BODY WEIGHT AND WEIGHT GAIN: There were no treatment-related effects.


FOOD CONSUMPTION: There were no treatment-related effects.


HAEMATOLOGY:There were no treatment-related effects.


CLINICAL CHEMISTRY: Although there were a few statistically significant changes in clinical chemistry parameters in males, the results were within historical control ranges and are not considered toxicologically significant.


NEUROBEHAVIOUR: There were no treatment-related effects.


ORGAN WEIGHTS : Absolute kidney weight was increased in all groups of males and relative kidney weights were increased in the 500 and 1000 mg/kg/day groups. The increase in kidney weight is related to hydrocarbon nephropathy, which is specific for male rats and is not considered to be toxicologically significant. Females also had an increased relative kidney weight in the 500 and 1000 mg/kg/day groups, but there was no histopathological changes in the kidney. High-dose males and females had an increase in relative liver weight, but there was no histopathological changes. Therefore, the changes in organ weight are considered not to be toxicologically significant.


GROSS PATHOLOGY: There were no treatment-related changes in gross pathology.


HISTOPATHOLOGY: NON-NEOPLASTIC: The only histopathology changes related to treatment were associated with the hydrocarbon nephropathy in males. This is not considered toxicologically significant because the effect is specific to male rats.



OTHER FINDINGS

Effect levels

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: overall effects

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

There were no toxicologically significant results related to treatment. Changes were either associated with hydrocarbon nephropathy, which is specific to male rats, or were incidental.

Applicant's summary and conclusion

Conclusions:

Based on the lack of significant adverse clinical effects, the NOAEL for C6 alkenes is 1000 mg/kg.

Executive summary:

In a short-term repeat dose toxicity study, C6 alkenes dissolved in corn oil were administered via oral gavage to male and female Sprague-Dawley rats (12/sex/dose) at dose levels of 100, 500 and 1000 mg/kg/day for 34 (males) or 38 (females) days. 

 

There was no mortality observed in either male or female rats at any of the doses tested in the oral toxicity study. Besides post-dosing salivation at 1000 mg/kg/day group, no significant signs of clinical toxicity were observed at any dose level. Functional observational evaluations revealed no significant differences between the treatment and control animals. Mean body weight, body weight gain, food consumption, haematology and clinical chemistry parameters were comparable to controls at all dose levels. Organ weight and gross necropsy evaluations revealed no significant adverse effects subsequent to oral treatment with C6 alkenes.

 

Based on the lack of significant adverse clinical effects, the NOAEL for C6 alkenes is 1000 mg/kg.

 

This study received a Klimisch score of 1 and is classified as reliable without restrictions becausethe study was compliant with GLPs set forth by OECD [ENV/MC/CHEM(98)17], and the study design was based on OECD guideline 422.