Gases (petroleum), catalytic-cracked gas oil depropanizer bottoms, C4-rich acid-free

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

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

Test material information

Constituent 1

Reference substance name:

Propane

EC Number:

200-827-9

EC Name:

Propane

Cas Number:

74-98-6

Molecular formula:

C3H8

IUPAC Name:

propane

Test animals

Species:

rat

Strain:

other: Alderley Park (SPF)

Sex:

male/female

Details on test animals or test system 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 levels

Effect levels 1

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 800 000 ppm

Exp. duration:

15 min

Effect levels 2

Sex:

male/female

Dose descriptor:

LC50

Effect level:

1 442 738 mg/m³ air

Exp. duration:

15 min

Effect levels 3

Sex:

male/female

Dose descriptor:

LC50

Effect level:

1 443 mg/L air

Exp. duration:

15 min

Effect levels 4

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.