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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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non guideline, non GLP, animal experimental study, limitations in design but adequate for assessment

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1982

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
To investigate the concentrations at which CNS effects occur following inhalation exposure to propane by measurement of the LC50 (15 min) and EC50 (CNS) (10 min) in rats.
GLP compliance:
not specified
Test type:
other: study to investigate the concentrations at which CNS effects occur
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
other: Alderley Park (SPF)
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Rats:
- Source: Alderley Park Breeding Unit, Macclesfield, Cheshire, UK
- Weight at study initiation: 190-230 g

Administration / exposure

Route of administration:
inhalation
Type of inhalation exposure:
whole body
Vehicle:
other: air
Details on inhalation exposure:
GENERATION OF TEST ATMOSPHERE: The gas was passed through a calibrated rotameter and was then mixed with the appropriate quantity of air; the animal was then exposed to the resultant atmosphere. Dynamic atmospheres were generated and gas chromatography was used to measure the concentration of test gas in the atmosphere. As soon as the atmospheric concentration of propane exceeded 25%, oxygen was mixed with the air to maintain a concentration of 20% oxygen.
CHAMBER: Volume = 500 mL
Analytical verification of test atmosphere concentrations:
yes
Remarks:
gas chromatography
Duration of exposure:
10 - 15 min
Concentrations:
A range of concentrations was used (0.24% - >80% v/v) such that the no-effect concentration, the 100% effect concentration and several in-between concentrations were determined. Details of the actual concentrations are not provided.
No. of animals per sex per dose:
6 rats
Control animals:
not specified
Details on study design:
Groups of six males or females were used, animals were exposed to the test gas in a 500 mL chamber through which the vapours of test material, mixed with air, were passed. The animals were observed for any effects on the central nervous system, which included stimulation (limb tremor) or depression (ataxia and loss of righting reflex), over a 10 min exposure period. A range of concentrations were used in order to determine both a no-effect concentration, the 100% effect concentration and other concentrations in-between. The EC50 for CNS effect concentration (at 10 min) was calculated, together with the concentration causing mortality after 15 min exposure (LC50 (15 min)).
Statistics:
The EC50, LC50 and 95% confidence intervals were calculated using the moving average interpolation technique of Thompson (1947).

Results and discussion

Effect levelsopen allclose all
Sex:
male/female
Dose descriptor:
LC50
Effect level:
> 800 000 ppm
Exp. duration:
15 min
Sex:
male/female
Dose descriptor:
LC50
Effect level:
1 442 738 mg/m³ air
Exp. duration:
15 min
Sex:
male/female
Dose descriptor:
LC50
Effect level:
1 443 mg/L air
Exp. duration:
15 min
Sex:
male/female
Dose descriptor:
other: EC50 (CNS)
Effect level:
280 000 ppm
95% CL:
220 000 - 350 000
Exp. duration:
10 min
Clinical signs:
other: Death following exposure to propane took the following form associated with a CNS depressant: slight ataxia, loss of righting reflex, loss of movement, narcosis, shallow respiration and death eventually from respiratory depression. Death always occurred d

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: other: EU (DSD)
Conclusions:
The acute inhalation toxicity of propane and its effect on the CNS of experimental rats was determined. The acute inhalation LC50 following 15 minute exposure exceeds 800000 ppm (equivalent to 1,442,738 mg/m3 or 1443 mg/L)). Propane caused depression of the rat CNS after 10 minutes inhalation exposure; EC50 (CNS) 280000 ppm (equivalent to 504,961 mg/m3 or 505 mg/L).
Executive summary:

The acute inhalation toxicity of propane and its effect on the CNS of experimental rats was determined.

The acute inhalation LC50following 15 minute exposure exceeds 800000 ppm (equivalent to 1,442,738 mg/m3 or 1443 mg/L).

Propane caused depression of the rat CNS after 10 minutes inhalation exposure; EC50(CNS) 280000 ppm (equivalent to 504,961 mg/m3 or 505 mg/L). (MW 44.094)

The non-lethal toxic effects were rapidly reversed on cessation of exposure, indicating rapid elimination from the body.