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Toxicological information

Acute Toxicity: inhalation

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Administrative data

Endpoint:
acute toxicity: inhalation
Type of information:
experimental study
Adequacy of study:
key study
Study period:
data not available
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study well documented, meets generally accepted scientific principles (similar to OECD test guideline 403), acceptable for assessment

Data source

Reference
Reference Type:
publication
Title:
Acute and subchronic toxicity studies of rats exposed to vapors of methyl mercaptan and other reduced-sulfur compounds
Author:
Tansy MF, Kendall FM, Fantasia J, Landin WE and Oberly R
Year:
1981
Bibliographic source:
Journal of Toxicology and Environmental Health, 8, 71-88

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 403 (Acute Inhalation Toxicity)
Deviations:
no
GLP compliance:
not specified
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): dimethyl sulfide (Aldrich Chemical Co., Milwaukee, Wis.)
- Physical state: liquid
- Analytical purity, Impurities (identity and concentrations), Purity test date, Lot/batch No., Expiration date of the lot/batch, Stability under test conditions, Storage condition of test material: data not available

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River
- Age at study initiation: adult males and females
- Weight at study initiation: 90 - 100 g on day of receipt
- Fasting period before study: data not available
- Housing: 5 per cage (except during exposure, where males and females were combined)
- Diet: pelleted Purina Laboratory Chow, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 7 days


ENVIRONMENTAL CONDITIONS
- Temperature: 22°C
- Humidity (%): data not available
- Air changes (per hr): data not available
- Photoperiod: constant light cycles (no other information available)


IN-LIFE DATES: data not available

Administration / exposure

Route of administration:
inhalation: vapour
Type of inhalation exposure:
whole body
Vehicle:
clean air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
Test substance is fed into the exposure chamber through inlet port and exhausted through tube. Gaseous effluent is passed through a filtering system before evacuation into the inside atmosphere. Gas mixture is pulled through the chamber by vacuum pump and the slightly negative chamber pressure is monitored by mercury manometer. Chamber temperature is monitored by thermonmeter.

Configuration of apparatus used to vaporize dimethyl sulfide: the liquid compound is pumped at a fixed rate from the syringe pump into the vaporization chamber, heated by the electric mantle via the variable transformer, where it vaporizes almost instantaneously. Room air is metered through the vaporization chamber by the flowmeter. The resulting mixture is further mixed with the main stream of room air monitored by flowmeter. The major portion of room air passing through the exposure chamber does not pass through the vaporization flask to prevent overheating of the exposure chamber. The resultant air-vapor mixture is drawn through the exposure chamber by a vacuum pump connected to the exhaust tube.

ANIMAL EXPOSURE
Each dose group consisted of 5 male and 5 female rats, which were combined for a 4-h exposure or sham exposure to air in a customized 75-l glass chamber and then separated for observation over the subsequent 14-day period. The rats were deprived of food and water during actual exposure or sham exposure.
Analytical verification of test atmosphere concentrations:
not specified
Duration of exposure:
4 h
Concentrations:
0, 800, 3000, 6000, 12000, 24000, 36000, 39000, 42000, 45000, 48000 ppm
(approximately 0, 2.03, 7.61, 15.2, 30.4, 60.9, 91.3, 98.9, 106, 114, or 122 g/L)
No. of animals per sex per dose:
5 males and 5 females per group
Control animals:
yes
Details on study design:
Animals from any group that died during the 14-day period were examined for gross pathology, such as general or local haemorrhage and adhesions, and the survivors were sacrificed and examined as well. Mortality and such visually apparent behaviour as exploring, huddling, preening, and obvious distress were noted during the course of the 4-hour exposure and sham exposure.
Statistics:
LC50 values and 95% confidence limits were estimated by the classical method of Litchfield and Wilcoxon (1949)

Results and discussion

Effect levels
Sex:
male/female
Dose descriptor:
LC50
Effect level:
40 250 ppm
95% CL:
38 018 - 42 613
Exp. duration:
4 h
Remarks on result:
other: # 102 g/m3
Mortality:
Any animal that survived the first 24 h after exposure survived to the end of the 2-wk observational period.
See table 1 below.
Clinical signs:
data not available
Body weight:
data not available
Gross pathology:
There was no evidence of external bleeding from any orifice in rats that succumbed or survived

Any other information on results incl. tables

Table 1: results

Dose (ppm)

Mortality

Sham

0 / 10

800

0 / 10

3000

0 / 10

6000

0 / 10

12000

0 / 10

24000

0 / 10

36000

2 / 10

39000

5 / 10

42000

5 / 10

45000

8 / 10

48000

9 / 10

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The 4-h inhalation LC50 in rats of dimethyl sulfide is 40250 ppm (# 102 g/m3).
Executive summary:

Five rats per sex per group were exposed for 4 hours to dimethyl sulfide vapor at 0, 800, 3000, 6000, 12000, 24000, 36000, 39000, 42000, 45000, or 48000 ppm (approximately 0, 2.03, 7.61, 15.2, 30.4, 60.9, 91.3, 98.9, 106, 114, or 122 mg/L).  The LC50 was 40250 ppm (102 mg/L) with a 95% confidence interval of 38018-42613 ppm (96.6 mg/L to 108.3 mg/L).  Animals were observed for 14 days following the exposure.  No data for clinical signs or body weight effects, were provided in the report.  Mortality was observed for some animals in all groups exposed to concentrations equal to or greater than 36000 ppm.  At necropsy, there was no evidence of external bleeding from any orifice in rats that succumbed or survived.