4-tert-butylcyclohexyl acetate

Endpoint summary

Description of key information

- Acute toxicity: oral (rats; combined): LD50 = 3370 mg/kg bw (similar to OECD 401, K, rel.2).

- Acute toxicity: inhalation: Waiver.

- Acute toxicity: dermal (rabbits, combined): LD50 > 4680 mg/kg bw (similar to OECD 402, K, rel.2)

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

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.

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

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- Fasting period before study: food was withdrawn at 4:00 p.m. on the day prior to treatment and the rats were fasted overnight.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).

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.

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.

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:

other: 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 over

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

None

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.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

3 370 mg/kg bw

Quality of whole database:

The key study is GLP-compliant and of high quality (Klimisch score = 2)

Acute toxicity: via inhalation route

Link to relevant study records

Reference

Endpoint:

acute toxicity: inhalation

Data waiving:

other justification

Justification for data waiving:

other:

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
In accordance with Column 2 of REACH Annex VIII, in addition to the oral route (8.5.1), for substances other than gases, the information mentioned under 8.5.2 (acute toxicity by inhalation) and 8.5.3 (acute toxicity by the dermal route) shall be provided for at least one other route. The choice for the second route will depend on the nature of the substance and the likely route of human exposure. In the present case, inhalation exposure will be lower than dermal exposure because the registered substance has a low vapour pressure (< 7.9 Pa at 20°C – from analogue) and a low freezing point (<-20°C), so the potential for the generation of inhalable forms is low. Dermal exposure is the more likely route of exposure based on physico-chemical properties (Log Kow = 4.8 at 25°C, WS = 39.6 mg/L at 20°C – from analogue).

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Link to relevant study records

Reference

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 1978

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. 402 with deviations: only 3 rabbits per sex were used.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

only 3 animals/sex; environmental conditions not reported

Principles of method if other than guideline:

Protocol #DLD (11/7/78) supplied by IFF and dated 12 October 1978

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: C.S.E. colony located in Brancheville, N.J.
- Age at study initiation: young adult
- Weight at study initiation: 2.45-3.50 kg
- Housing: singly
- Diet (e.g. ad libitum): Purina Rabbit Chow
- Water (e.g. ad libitum): ad libitum
- Acclimation period: at least 7 days

ENVIRONMENTAL CONDITIONS
Standard laboratory conditions

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: shaved skin on the back
- % coverage: approximately 20 %
- Type of wrap if used: plastic sleeves ('Baggies')

REMOVAL OF TEST SUBSTANCE
- Washing (if done): disposable napkin moistened with saline
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 5 mL/kg bw

Rabbits were placed in restrainers for the 24 hour period following application.

Duration of exposure:

24 hours

Doses:

5 mL/kg bw

No. of animals per sex per dose:

3

Control animals:

not required

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations (signs of toxicity and death): twice daily (once daily on Saturday and Sunday)
- Frequency of observations and weighing: on the day of dosing and before necropsy
- Necropsy of survivors performed: yes

Statistics:

none

Preliminary study:

not applicable

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

> 5 mL/kg bw

Based on:

test mat.

Key result

Sex:

male/female

Dose descriptor:

LD0

Effect level:

>= 5 mL/kg bw

Based on:

test mat.

Mortality:

No animal died during the study

Clinical signs:

other: Slight to moderate erythema was observed during the first 24 hours after application. All rabbits exhibited a slight scaliness over the treated area, which was first observed on Day 8 and persisted to the end of the study.

Gross pathology:

Agonal subcapsular haemorrhage observed in the right or left kidney in 2 rabbits. Pale liver in 1 rabbit.

Other findings:

None

None

Interpretation of results:

GHS criteria not met

Conclusions:

Dermal LD50Combined > 5 mL/kg bw (> 4680 mg/kg bw)
Under the test conditions, the test material is not classified according to the Regulation EC No. 1272/2008 (CLP) and to the GHS.

Executive summary:

In a limit acute dermal toxicity study performed before but similarly to the OECD guideline No. 402, groups of young adult albino New Zealand rabbits (3/sex) were occlusively exposed to undiluted test material for 24 hours at dose of 5 mL/kg bw (ca. 4680mg/kg bw; density = 0.936). The animals were observed for mortality, clinical signs including dermal reactions and body weight for 14 days and then necropsied for macroscopic observations.

 

No mortality occurred during the study and no clinical signs were observed. There was no adverse effect on bodyweight gain. Slight to moderate erythema was observed during the first 24 hours after application. All rabbits exhibited a slight scaliness over the treated area, which was first observed on Day 8 and persisted to the end of the study.

 

Dermal LD₅₀Combined > 5 mL/kg bw (> 4680 mg/kg bw)

 

Under the test conditions, the test material is not classified according to the Regulation EC No. 1272/2008 (CLP) and to the GHS.

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

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

4 680 mg/kg bw

Quality of whole database:

Although conducted using only 3 animals/dose/sex, the results were supported by two other studies conducted using 5 animals/dose/sex each.

Additional information

Acute toxicity: oral

5 studies were available. Therefore, the study with the lowest LD50 value (CSE, 1979, rel.2) was selected as the key study. In this acute oral toxicity study performed before but similarly to the OECD test guideline No. 401, groups of rats (8/sex) were administered a single oral dose of 4 -tert butylcyclohexyl acetate by gavage at dose levels of 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).

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.

Similar findings were observed on an analogue substance, cis--4 -tert-butylcyclohexyl acetate (Harlan, 2013). Indeed, in this acute oral toxicity study performed according to the OECD test guideline No. 420 and in compliance with GLP, signs of systemic toxicity noted in animals treated at a dose level of 2000 mg/kg bw were hunched posture, ataxia, lethargy and occasional body tremors. Two animals treated at a dose level of 2000 mg/kg bw were found dead one or two days after dosing. There were no deaths at a dose level of 300 mg/kg bw. Abnormalities noted at necropsy of the animals that died during the study were abnormally red lungs, dark liver, dark or pale kidneys and epithelial sloughing of the gastric mucosa and non-glandular epithelium of the stomach. No abnormalities were noted at necropsy of animals that were killed at the end of the study.

Acute toxicity: dermal

3 studies were available. Therefore, the study with the lowest LD50 value (CSE, 1979, rel.2) was selected as the key study. In this limit acute dermal toxicity study performed before but similarly to the OECD guideline No. 402 and in compliance with GLP, groups of rabbits (3/sex) were occlusively exposed to undiluted 4 -tert-butylcyclohexyl acetate for 24 hours at dose of 5 mL/kg bw (ca. 4680mg/kg bw; density = 0.936). No mortality occurred during the study and no clinical signs were observed. There was no adverse effect on bodyweight gain. Slight to moderate erythema was observed during the first 24 hours after application. All rabbits exhibited a slight scaliness over the treated area, which was first observed on Day 8 and persisted to the end of the study.

Dermal LD50 Combined > 5 mL/kg bw (> 4680 mg/kg bw).

Although conducted using only 3 animals/dose/sex, the results were supported by two other studies conducted using 5 animals/dose/sex each (MB, 1976 and FDRL, 1976) which both gave a LD50 value > 5000 mg/kg bw.

Acute toxicity: inhalation

In accordance with Column 2 of REACH Annex VIII, in addition to the oral route (8.5.1), for substances other than gases, the information mentioned under 8.5.2 (acute toxicity by inhalation) and 8.5.3 (acute toxicity by the dermal route) shall be provided for at least one other route. The choice for the second route will depend on the nature of the substance and the likely route of human exposure. In the present case, inhalation exposure will be lower than dermal exposure because the registered substance has a low vapour pressure (< 7.9 Pa at 20°C – from analogue) and a low freezing point (<-20°C), so the potential for the generation of inhalable forms is low. Dermal exposure is the more likely route of exposure based on physico-chemical properties (Log Kow = 4.8 at 25°C, WS = 39.6 mg/L at 20°C – from analogue).

Justification for classification or non-classification

Harmonised classification:

The substance has no harmonised classification according to the Regulation (EC) No. 1272/2008 (CLP).

Self classification:

Acute toxicity via Oral route:

Based on the available information, the substance is:

- not classified according to the CLP as the LD50 is greater than 2000 mg/kg bw

- classified under category 5 under the GHS as the LD50 is between 2000 and 5000 mg/kg bw.

Acute toxicity via Dermal route:

Based on the available information, the test item is:

- not classified according to the CLP as the LD50 is greater than 5000 mg/kg bw

- not classified according to the GHS as the LD50 is greater than 5000 mg/kg bw.

Acute toxicity via Inhalation:

No information was available.

Specific target organ toxicity: single exposure (Oral):

The classification criteria according to the CLP and to the GHS as specific target organ toxicant (STOT) – single exposure, oral are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value (oral) for a Category 1 classification (C≤ 300 mg/kg bw) and at the guidance value (oral) for a Category 2 classification (2000 mg/kg bw≥C > 300 mg/kg bw). No classification is required.

The criteria for Transient Organ effects (STOT-SE Category 3) according to the CLP and to the GHS are not met since narcotic effects were not observed in the acute oral toxicity study.

Specific target organ toxicity: single exposure (Dermal):

The classification criteria according to the CLP and the GHS as specific target organ toxicant (STOT) – single exposure, dermal are not met since no reversible or irreversible adverse health effects were observed immediately or delayed after exposure and no effects were observed at the guidance value (dermal) for a Category 1 classification (C ≤ 1000 mg/kg bw) and at the guidance value (dermal) for a Category 2 classification (2000 mg/kg bw ≥ C > 1000 mg/kg bw). No classification is required.

The criteria for Transient Organ effects (STOT-SE Category 3) according to the CLP and to the GHS are not met since narcotic effects were not observed in the acute oral toxicity study.

Specific target organ toxicity: single exposure (Inhalation):

No information was available.

Aspiration hazard:

The substance is not a hydrocarbon and no effects were observed on lungs in oral studies, therefore the criteria for aspiration toxicity according to the CLP and to the GHS are not met.