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Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
From 1978-11-22 to 1979-04-30
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Remarks:
Old study (pre-OECD and pre-GLP) but comparable to OECD test guideline No. 401.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1979
Report date:
1979

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Deviations:
no
Principles of method if other than guideline:
Protocol OLD (11/7/79) supplied by International Flavors and Fragrances and dated 15 November 1978
GLP compliance:
no
Remarks:
pre-GLP
Test type:
standard acute method
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
trans-4-tert-butylcyclohexyl acetate
EC Number:
217-598-6
EC Name:
trans-4-tert-butylcyclohexyl acetate
Cas Number:
1900-69-2
Molecular formula:
C12H22O2
IUPAC Name:
trans-4-tert-butylcyclohexyl acetate
Constituent 2
Chemical structure
Reference substance name:
cis-4-tert-butylcyclohexyl acetate
EC Number:
233-881-7
EC Name:
cis-4-tert-butylcyclohexyl acetate
Cas Number:
10411-92-4
Molecular formula:
C12H22O2
IUPAC Name:
cis-4-tert-butylcyclohexyl acetate
Test material form:
liquid
Details on test material:
- Description: clear viscous liquid

Test animals

Species:
rat
Strain:
other: TaCN(SD)fBR
Sex:
male/female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Taconic Farms, Germantown, N.Y.
- Age at study initiation: young adult
- Weight at study initiation: 180-220 g
- Fasting period before study: food was withdrawn at 4:00 p.m. on the day prior to treatment and the rats were fasted overnight.
- Housing: singly in wire mesh cages
- Diet (e.g. ad libitum): Purina Rodent Laboratory Chow 5001 ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
Standard laboratory conditions meeting the standards described in the "Guide for the care and Use of Laboratory Animals" (DHEW Publication No. (NIH) 78-23 Revised 1978).

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
RANGE FINDING
- Rationale for the selection of the starting dose: 2 males/dose, observed during 72 hours for mortality only. The dosages were 1.0, 2.0, 3.0, 4.0 and 5.0 mL/kg bw.
Doses:
2.0, 2.5, 3.18, 4.0, 4.5 and 5.04 mL/kg bw (ca. 1872, 2340, 2995, 3744, 4212, 4680 mg/kg bw)
No. of animals per sex per dose:
8/sex/dose, except for the 4.5 mL/kg bw dose level for which 8 males were used only.
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations: 1, 3, 5 and 24 hours following dosing and twice daily (once at weekends) for the remainder
- Necropsy of survivors performed: yes
- Other examinations performed: pharmacotoxic signs
Statistics:
The LD50, slopes and fiducial limits were estimated by the graphic method of Litchfield and Wilcoxon (1949). Using the Two Sample Independent T test based on the estimated standard deviation obtained from these values, there was statistically no difference between male and female mortality, thus the data from both sexes were pooled to obtain the combined LD50, slope and fiducial limits.

Results and discussion

Preliminary study:
Three animals died in the 72 hour observation period, one at 4.0 mL/kg bw and two at 5 mL/kg bw. Therefore the test doses selected for the study were 2.0, 2.5, 3.2, 4.0, 4.5 and 5.0 mL/kg bw.
Effect levelsopen allclose all
Key result
Sex:
male/female
Dose descriptor:
LD50
Effect level:
3.6 mL/kg bw
Based on:
test mat.
95% CL:
>= 3.17 - <= 4.09
Remarks on result:
other: ca. 3370 mg/kg bw
Key result
Sex:
male
Dose descriptor:
LD50
Effect level:
4.15 mL/kg bw
Based on:
test mat.
95% CL:
>= 3.52 - <= 4.9
Remarks on result:
other: ca. 3885 mg/kg bw
Key result
Sex:
female
Dose descriptor:
LD50
Effect level:
3.55 mL/kg bw
Based on:
test mat.
95% CL:
>= 2.93 - <= 4.3
Remarks on result:
other: ca. 3323 mg/kg bw
Mortality:
At 2.0 mL/kg bw, only one female died, between 24 and 48 hours after being dosed. At higher doses, up to 4.5 mL/kg bw, death occurred more than 12 hours after dosing and were spaced over several days. At 5.0 mL/kg bw, the majority of deaths occurred between 12 and 24 hours after dosing, but the reminder of deaths were spread over the next four days.
Clinical signs:
At all doses, animals became hypoactive about 20 minutes after treatment. At 2.0 mL/kg bw one female rat became hyperactive and showed some limb twitching about 30 minutes after treatment; but otherwise animals in this doe group showed no evidence of overt systemic toxicity during the first 24 hours or thereafter, except chromorhinorrhea or chromodacryorrhea which are non-specific signs of stress.
At 2.5 mL/kg bw and higher doses, the principle signs in the first 24 hours following initial hypoactivity were tremors and twitching and a low incidence of convulsions. Most rats were weak and appeared reluctant to move or be moved from 24-48 hours after dosing. Thereafter, survivors showed no specific symptoms, but most had chromorhinorrhea or chromodacryorrhea at various times.
Body weight:
No effect
Gross pathology:
- Animal which died: acute congestion in the small intestines, particularly in the jejuna area. This injury leads to rapid autolysis of the intestine in several animals which died overnight. In the thorax an increased incidence of congested lungs occurred at the higher doses.
- Animal killed at term: non-specific lesions were observed in two rats treated at 2.5 mL/kg bw; in one, the lungs contained a large pale area, possibly resulting from a dosing accident, and in the other rat there was slight congestion of the lungs.
Other findings:
None

Any other information on results incl. tables

None

Applicant's summary and conclusion

Interpretation of results:
Category 5 based on GHS criteria
Conclusions:
Oral LD50Combined = 3.60 mL/kg bw (3.17-4.09) <=> ca. 3370 mg/kg bw
Oral LD50Males = 4.15 mL/kg bw (3.52-4.90) <=> ca. 3885 mg/kg bw
Oral LD50Females = 3.55 mL/kg bw (2.93-4.30) <=> ca. 3323 mg/kg bw
Under the test conditions, 78 -059 -03 is not classified according to the Regulation EC No. 1272/2008 (CLP) but is classified in Category 5 based on GHS criteria.
Executive summary:

In an acute oral toxicity study performed before but similarly to the OECD test guideline No. 401, groups of fasted, young adult, TaCN(SD)fBR rats (8/sex) were administered a single oral dose of 78 -059 -03 by gavage. The animals were observed for mortality, clinical signs and body weight for 14 days and then necropsied for macroscopic observations.

 

Doses were selected from a preliminary assay in which rats were treated at 1.0, 2.0, 3.0, 4.0 and 5.0 mL/kg bw. There was one death at 4.0 mL/kg bw and two deaths at 5.0 mL/kg bw. Therefore 2.0, 2.5, 3.18, 4.0, 4.5 and 5.04 mL/kg bw (ca. 1872, 2340, 2995, 3744, 4212, 4680 mg/kg bw) were selected for the main study.

 

Oral LD50 Combined = 3.60 mL/kg bw (3.17-4.09) <=> ca. 3370 mg/kg bw

Oral LD50 Males = 4.15 mL/kg bw (3.52-4.90) <=> ca. 3885 mg/kg bw

Oral LD50 Females = 3.55 mL/kg bw (2.93-4.30) <=> ca. 3323 mg/kg bw

 

Animals became hypoactive after dosing. In the first 24 hours, the principle clinical signs were tremors; twitching of the limbs and, at a low incidence, convulsions. Between 24 and 48 hours the principle signs were a reluctance to move. Thereafter, survivors showed few clinical signs except chromodacryorrhea. Deaths occurred after 12 hours and were spaced over the next six days. The most prominent sign at necropsy was congestion and early autolysis of the small intestine.

 

Under the test conditions, 78 -059 -03 is not classified according to the Regulation EC No. 1272/2008 (CLP) but is classified in Category 5 based on GHS criteria.

This study is considered as acceptable and satisfies the requirement for acute oral toxicity endpoint.