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Administrative data

Description of key information

The LD50 values derived from the key studies were: LD50 (oral, rat) 600 mg/kg bw and LD50 (dermal, rat) 1000 mg/kg bw.

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:
1962
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable publication which meets basic scientific principles.
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Deviations:
not specified
Principles of method if other than guideline:
Method: other: Smyth/Carpenter
GLP compliance:
no
Remarks:
prior to GLP
Test type:
standard acute method
Limit test:
no
Species:
rat
Strain:
other: Carworth-Wistar
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Colony of the Mellon Institute of Industrial Research (Pittsburgh, Pennsylvania, USA) (in-house breeding)
- Age at study initiation: 4-5 weeks old
- Weight at study initiation: 90 to 120 g
- Fasting period before study: no
- Diet: Rockland rat diet complete
Route of administration:
oral: gavage
Vehicle:
other: water, corn oil or 1 % Tergitol Penetrant 7
Details on oral exposure:
(Dose volume: 1 to 10 mL/rat, oral gavage)
Doses:
Logarithmic series of dose levels
No. of animals per sex per dose:
5 animals
Control animals:
not specified
Details on study design:
- Duration of observation period following administration: 14 days
Statistics:
The most probable LD50 was estimated by the methods of Thompson (1947) and Weil (1952).
Sex:
male
Dose descriptor:
LD50
Effect level:
600 mg/kg bw
Remarks on result:
other: reported as 0.60 mL/kg bw
Sex:
male
Dose descriptor:
LD50
Effect level:
>= 0.43 - <= 0.84 mL/kg bw
Mortality:
Death occurred within 14 days, no detailed information provided.
Clinical signs:
No information provided
Body weight:
No information provided
Gross pathology:
No information provided

single oral gavage, deaths within 14 days. Limits of +/- 1.96 standard deviation using the method of Thompson: 430 - 840 mg/kg bw. Original LD50 given as 0.6 mL/kg bw.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LD50
600 mg/kg bw
Quality of whole database:
Acceptable publication.

Acute toxicity: via inhalation route

Link to relevant study records
Reference
Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1962
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable publication which meets basic scientific principles.
Principles of method if other than guideline:
Method: other: Smyth/Carpenter
GLP compliance:
no
Remarks:
prior to GLP
Test type:
standard acute method
Limit test:
no
Species:
rat
Strain:
other: albino
Sex:
male/female
Details on test animals and environmental conditions:
Name of the test material: 1-Ethynylcyclohexanol
Route of administration:
inhalation
Type of inhalation exposure:
whole body
Vehicle:
air
Details on inhalation exposure:
INHALATION EXPOSURE AND TEST ATMOSPHERE
Concentrated vapor inhalation consisted of subjecting animals to a flowing stream of vapor-ladened air prepared by various styles of proportioning pumps. The vapor-air mixture was generated by passing 2.5 Liters/minute of dried air at room temperature through a fritted glass disc immersed to a depth of at least one inch in approximately 50 mL of the test chemical contained in a gas-washing bottle.
Analytical verification of test atmosphere concentrations:
no
Duration of exposure:
8 h
Concentrations:
Logarithmic series of vapor concentrations
No. of animals per sex per dose:
6 animals (male or female)
Control animals:
no
Details on study design:
INHALATION EXPOSURE TIMES
Rats were rapidly introduced by means of a drawer-type cage designed to minimize vapor loss. Inhalation of metered vapor concentrations were conducted were usually of four hours' duration unless slight toxicity enforces an eight-hour period (maximum period). For inhalation periods of ten, five and two minutes in duration, a static technique is used whereby 50 to 100 grams of material, spread over a shallow tray 200 square inches in area, is placed in a 120-Liter sealed chamber for at least 24 hours. This method was also employed for mixtures of liquids and for solids. Nominal concentrations were not analytically verified. They were in an essentially logarithmic series with a factor of two with a ratio of two extending from one-fourth to eight hours.

OBSERVATIONS
The period which permitted all rats to survive the two-week observation period was noticed. The concentration yielding fractional mortality was noticed. Where no fractional mortality was observed, usually both the concentration yielding no mortality and that yielding complete mortality were indicated.
Dose descriptor:
LC0
Based on:
test mat.
Exp. duration:
8 h
Remarks on result:
other: saturated atmosphere
Mortality:
No mortality was observed.
Clinical signs:
No information provided
Body weight:
No information provided
Gross pathology:
No information provided

No mortality was observed when 6 rats were exposed for 8 hours to an atmosphere that had been saturated at room temperature with the volatile part of the compound.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Quality of whole database:
Acceptable publication.

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:
1962
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Acceptable publication which meets basic scientific principles.
Principles of method if other than guideline:
Method: other: Smyth/Carpenter
GLP compliance:
no
Remarks:
prior to GLP
Test type:
standard acute method
Limit test:
no
Species:
rabbit
Strain:
New Zealand White
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: young adult (based on body weight)
- Weight at study initiation: 2.5 - 3.5 kg
Type of coverage:
occlusive
Vehicle:
not specified
Details on dermal exposure:
Penetration of rabbit skin was estimated by the one-day cuff method of Draize and associates. The fur was closely clipped over the entire trunk, and the dose retained beneath an impervious plastic film.
Duration of exposure:
24 hours
Doses:
up to 20 mL/kg bw
No. of animals per sex per dose:
4 animals
Control animals:
not specified
Details on study design:
After 24 hours contact the film was removed. Mortality was considered complete after 14 additional days.
- Duration of observation period following administration: 14 days
Statistics:
The most probable LD50 was estimated by the methods of Thompson (1947) and Weil (1952).
Sex:
male
Dose descriptor:
LD50
Effect level:
1 000 mg/kg bw
Remarks on result:
other: reported as 1.00 mL/kg bw
Sex:
male
Dose descriptor:
LD50
Effect level:
>= 0.68 - <= 1.48 mL/kg bw
Mortality:
Death occurred within 14 days, no detailed information provided.
Clinical signs:
No information provided
Body weight:
No information provided
Gross pathology:
No information provided

24 h exposure time, deaths within 14 days. Limits of +/- 1.96 standard deviation using the method of Thompson: 680 - 1480 mg/kg bw. Original LD50 given as 1.0 mL/kg bw.

Endpoint conclusion
Endpoint conclusion:
adverse effect observed
Dose descriptor:
LD50
1 000 mg/kg bw
Quality of whole database:
Acceptable publication.

Additional information

Acute toxicity: oral
In a single dose study (Smyth et al., 1962), acute oral toxicity of 1-Ethinylcyclohexanol was estimated by oral gavage in 5 male Carworth-Wistar rats per dose level using a logarithmic series of doses. 1-Ethinylcyclohexanol was diluted with a vehicle when necessary (to bring the dose volume to 1 to 10 mL per rat). 14 days after dosing, mortality was considered as complete. Oral administration of 1-Ethinylcyclohexanol to female rats resulted in a LD50 value of 600 mg/kg bw. This study is classified as acceptable (key study).

Additionally, in a reliable study published by U.S. EPA (1992) a LD50 value of 1150 mg/kg bw was listed. Furthermore, in a single dose study (BASF, 1952) a LD50 value >300 mg/kg bw was determined. Both studies are classified as acceptable (supporting studies).

 

Acute toxicity: inhalation

In an acute inhalation toxicity study based on a concentrated vapor inhalation method (Smyth et al., 1962), six albino rats were exposed to logarithmic series of vapor concentrations of 1-Ethynylcyclohexanol for periods up to 8 hours and observed for 14 days. An 8 hours exposure to a flowing stream of vapor-loadened air with the test substance resulted in no mortality. Thus, inhalation of a concentrated vapor of 1-Ethynylcyclohexanol did not pose an acute risk to animal’s health. This acute inhalation toxicity study is classified as acceptable (key study).

 

Acute toxicity: dermal

In an acute dermal toxicity study (Smyth et al., 1962), four male rabbits were exposed to 1-Ethynylcyclohexanol. The test material was applied in a single dose to the clipped skin of the entire trunk beneath an impervious plastic film. After 24 hour exposure the film was removed, and mortality was considered complete after 14 additional days of observation. Death occurred within the observation period. Limits of ±1.96 standard deviation using the method of Thompson were 0.68 – 1.48 mL/kg bw. The LD50 determined in this study was 1.0 mL/kg bw (corresponding to ~1000 mg/kg bw). This study is classified as acceptable. It satisfies the guideline requirement for an acute dermal study according OECD 402 in principle (key study).


Justification for selection of acute toxicity – oral endpoint
The key study was selected.

Justification for selection of acute toxicity – inhalation endpoint
The key study was selected.

Justification for selection of acute toxicity – dermal endpoint
The key study was selected.

Justification for classification or non-classification

Based on the results of the oral acute toxicity study, 1-Ethynylcyclohexanol is classified as Xn, R22 (harmful if swallowed) according to the criteria of EU Directive 67/548/EEC and as Cat. 4, H302 (harmful if swallowed) according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No 1272/2008.

 

Based on the results of the dermal acute toxicity study, 1-Ethynylcyclohexanol is classified as Xn, R21 (harmful in contact with skin) according to the criteria of EU Directive 67/548/EEC and as Cat. 3, H311 (toxic in contact with skin) according to EU Classification, Labelling and Packaging of Substances and Mixtures (CLP) Regulation (EC) No 1272/2008.