Octane-1-thiol

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1986-11-06 to 1986-12-02

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: This study was classified as reliable with restrictions because it was well conducted and document and does appear to have largely followed OECD guideline 403 recommendations, but the specifics of the followed HUK protocol P2885d was not provided..

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1986

Report date:

1986

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: HUK protocol number P2885d

Deviations:

yes

Remarks:

Animals were exposed to test article for 4.5 hours as a result of a generator stoppage during the first half hour. Oxygen concentration was recorded at 30 minute intervals.

GLP compliance:

yes

Test type:

standard acute method

Test material

Test material information

Constituent 1

Reference substance name:

Octane-1-thiol (CAS # 111-88-6)

IUPAC Name:

Octane-1-thiol (CAS # 111-88-6)

Details on test material:

- Name of test material (as cited in study report): octane-1-thiol

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 Ltd. Margate.
- Age at study initiation: 6 to 8 weeks
- Weight at study initiation: 180 to 200
- Housing: grid-floor cages by sex
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 7 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 25
- Humidity (%): 40 to 70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 1986-11-06 To: 1986-12-02

Administration / exposure

Route of administration:

inhalation

Type of inhalation exposure:

head only

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Dynamic continuous flow system with a heated J-tube and an in-line air filter connected to a generator
- Exposure chamber volume: 10 Liters
- Source and rate of air: Filtered air at 5-20 L/minute
- Method of holding animals: two horizontal rows with tubes for holding animals
- Temperature, humidity, pressure in air chamber: Maintained at 22 ± 2°C

TEST ATMOSPHERE
- Brief description of analytical method used: The concentration of the test article was measured twice every hour by sampling through a Miran 1A infra-red gas analyzer set at a wavelength of 3.42 µm and a path length of 2.25 m.
- Samples taken from breathing zone: yes

VEHICLE
- Composition of vehicle (if applicable): Filtered air
- Concentration of test material in vehicle (if applicable): 0.24 mg/L

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4.5 h

Concentrations:

518 ppm (3.10 mg/L)

No. of animals per sex per dose:

5 per sex per dose

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Hourly during exposure and on day of exposure; once daily for the subsequent 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology

Statistics:

Mean and standard deviations were calculated where appropriate.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 3.1 mg/L air

Exp. duration:

4.5 h

Remarks on result:

other: 3.1 mg/L = 518 ppm

Mortality:

There were no deaths during the course of the study.

Clinical signs:

other: Clinical signs observed were ataxia, lethargy, salivation, lachrymation, and piloerection on the day of exposure. Piloerection was also noted on the following day. There were no treatment-related macroscopic or microscopic changes evident.

Gross pathology:

No treatment-related microcscopic or macroscopic changes were observed in animals through the study period.

Applicant's summary and conclusion

Interpretation of results:

other: Octane-1-thiol vapour was not acutely toxic to rats following inhalation for 4.5 hours at a concentration of 518 ppm (3.1 mg/L)

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

This study reported no toxic effects in rats exposed to octane-1-thiol by head only inhalation. The LC50 was determined to be >3.1 mg/L.

Executive summary:

In an acute inhalation toxicity study, young adult Sprague-Dawley rats (5/sex) were exposed (head only), to 3.10 mg/L octane-1-thiol for 4.5 hours. Animals then were observed for 14 days. 

 

There were no treatment-related macroscopic or microscopic changes evident. Clinical signs observed during the study were ataxia, lethargy, salivation, lachrymation, and piloerection on the day of exposure. Piloerection was also noted on the following day. The inhalation LC₅₀ was not possible to calculate from the experiment, but was determined to be greater than 3.10 mg/L in males and females.

 

This study received a Klimisch score of 2 and was classified as reliable with restrictions because it was well conducted and document and does appear to have largely followed OECD guideline 403 recommendations, but the specifics of the followed HUK protocol P2885d was not provided.