Propene

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Non GLP (predates implementation of GLP) non-guideline animal and human experimental study, acceptable with restrictions.

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

1924

Materials and methods

Principles of method if other than guideline:

A cat was made to breathe a range of concentrations of propene in and out of a respirator and monitored for blood pressure, heart rate and respiratory rate by means of cannulae inserted into the carotid artery and trachea.

GLP compliance:

no

Test type:

other: Investigative study

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Propene

EC Number:

204-062-1

EC Name:

Propene

Cas Number:

115-07-1

Molecular formula:

C3H6

IUPAC Name:

prop-1-ene

Constituent 2

Reference substance name:

Propylene

IUPAC Name:

Propylene

Constituent 3

Reference substance name:

1-propene

IUPAC Name:

1-propene

Details on test material:

Propene gas prepared in the laboratory: 96-98 % propene, the residue being, in part, hydrogen.

Test animals

Species:

cat

Strain:

not specified

Sex:

not specified

Administration / exposure

Route of administration:

inhalation: gas

Type of inhalation exposure:

other: via respirometer

Vehicle:

other: air

Details on inhalation exposure:

Cat was made to breathe in and out of a respirometer constructed so that propene or oxygen could be run in at any desired percentage. Soda lime was placed inside the respirometer to absorb CO2. Gas samples could also be removed for analysis. Oxygen used by the animal was replaced.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

> 30

Remarks on duration:

in 3 typical protocols cited in the paper, propene in oxygen was administered for approximately 1.5 hours and propene in air for approximately 0.5 hours

Concentrations:

In 3 typical protocols cited: Concentration of propene in oxygen varied from 16%-64% in one animal, 18-71% in a second and the concentration of propene in air varied from 16 - 37% in air.

No. of animals per sex per dose:

unknown

Control animals:

no

Details on study design:

Cats inhaled propene (96-98% pure) via a delicately counterpoised respirator. The animals had cannulas inserted, under anaesthesia, to allow recording of blood pressure, heart rate and respiratory rate. Anaesthesia was assessed as complete when stimulation of the exposed saphenous nerve failed to cause movement and caused very slight/no changes in respiration or blood pressure. The degree of anaesthesia achieved with different concentrations of propene in oxygen was determined. Subsequently, the degree of anaesthesia achieved when the % concentration of propene in air varied was also assessed.

Studies were conducted in humans with no details of experimental design recorded.

Statistics:

none

Results and discussion

Effect levels

Key result

Sex:

not specified

Dose descriptor:

other: fall in blood pressure under anaesthesia

Effect level:

> 65 other: %

Exp. duration:

60 min

Remarks on result:

other: (1,120,000 mg/m3), anaesthesia quickly induced with concentration of propene above 37% (637,000 mg/m3) and was maintained at 20-30% (344,000-516,000 mg/m3), followed by good recovery; however, above 65% rapid anaesthesia but blood pressure started to fall

Other findings:

Propene possesses anaesthetic properties.
Anaesthesia induced in a few minutes with propene concentration of 37% to 50%.  Anaesthesia occurred within 2 mins at 70% but cats recovered quickly with no long term effects.  Maintenance of anaesthesia at concentrations of 16% to 31% without any signs of poisoning.  No toxic effects noted at concentrations up to 53%.  At 65%  propene, blood pressure fell very slowly; at 70% fairly rapid fall in blood pressure.

In addition, propene was inhaled, by human volunteer(s) at 50% concentration: anaesthesia was induced in about 2 minutes. The induction was reported to be not unpleasant. Anaesthesia was maintained for a few minutes. Recovery was quite rapid and there were no unpleasant side effects

Applicant's summary and conclusion

Conclusions:

Anaesthesia was induced in a few minutes with 37% to 50% (370000-500000 ppm) propene. Anaesthesia occurred within two minutes at 70% but the cats recovered quickly with no long term effects. Maintenance of anaesthesia was carried out at 16% to 31% without any signs of poisoning. No toxic effects were noted at concentrations up to 53%. At 65% propene, blood pressure fell very slowly; at 70% there was a fairly rapid fall in blood pressure. 50% propene has been used in experimental anaesthesia studies in humans with no unpleasant side effects.