Propionaldehyde

Acute Toxicity: inhalation

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:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Reference 2

Reference Type:

secondary source

Title:

Propionaldehyd BUA-Stoffbericht 195

Author:

Beratergremium für umweltrelevante Altstoffe (BUA)

Year:

1996

Bibliographic source:

S. Hirzel Wiss. Verl.-Ges. 1997, Stuttgart

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

although the nominal concentration was 5.3 mg/L, the actual concentration of respirable substances was only 4.6 mg/L

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Propionaldehyde

EC Number:

204-623-0

EC Name:

Propionaldehyde

Cas Number:

123-38-6

Molecular formula:

C3H6O

IUPAC Name:

propanal

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 Breeding Laboratories, Wilmington, Massachusetts
- Weight at study initiation: female: 221 - 250g, male: 236 - 288g
- Fasting period before study: during exposure no food and no water
- Housing: single, but during exposure animals were group housed
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 20 days

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: Plexiglas® exposure chamber
- Exposure chamber volume: 100 liter
- Source and rate of air: 25 liter per minute
- System of generating particulates/aerosols: The test material was placed in a 50 ml glass syringe mounted on a Sage Syringe Pump (Model #352) with a syringe size setting of 50 and a flow rate of 10 to yield an actual flow rate of 10 ml/hr. The test material was fed, via Tynon tubing, to a 500 ml three-neck flask maintained at 25°C in a water bath heated by a Braun Thermomix (Model 1420) and was flash evaporated. Dry air at a flow rate of 25 liters per minute was passed through the flask. The resulting test atmosphere was directed, undiluted, into the exposure chamber.
- Method of particle size determination: Particle size distribution samples were taken using the Royco Portable Particle Monitor Model 218 at approximately hourly intervals throughout the exposure.
- Temperature, humidity, pressure in air chamber: The mean chamber temperature was 24°C and the mean relative humidity was 88%.


TEST ATMOSPHERE
- Brief description of analytical method used: The generation apparatus and test material were weighed before and after the exposure. The difference in weight represented the total amount of test material delivered into the chamber; this, divided by the total volume of air delivered yielded the nominal exposure concentratlon. Chamber concentrations were determined by using a Miran Infrared Spectrophotometer. The concentration of the test material in the chamber was determined by comparlng the absorption of these samples to a calibration curve with the same instrumental settings.
- Samples taken from breathing zone: yes

TEST ATMOSPHERE (if not tabulated)
- Particle size distribution: no aerosol concentration

Analytical verification of test atmosphere concentrations:

yes

Remarks:

see "Details on inhalation exposure"

Duration of exposure:

4 h

Concentrations:

4.6 mg/l

No. of animals per sex per dose:

5 male and 5 female rats

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: The animals were observed for abnormal signs before exposure, every fifteen minutes during the first hour of exposure, hourly through exposure, and daily thereafter for 14 days. Individual body weights for all rats were recorded on day 0 (prior to exposure) and on days 1, 2, 4, 7 and 14.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight, histopathology

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 4.6 mg/L air (analytical)

Exp. duration:

4 h

Mortality:

no mortality occured

Clinical signs:

other: Some rats exhibited lacrimation during the exposure period. This response commenced after 15 minutes of exposure. After removal from the exposure chamber, some rats exhibited lacrimation for up to four hours post-exposure. This sign had persisted until da

Body weight:

Although small, transient weight-losses were seen in most rats (due to exposure procedure), the body weights recovered to pre-exposure values in males by day 2 and in females by day 14. Body weight increments in the second week were within the limits of normal expectation for most animals. One animal showed a lower than normal weight gain in the second week, but when viewed in conjunction with the in-life observations and necropsy findings (vide supra/vide infra), this lower weight gain was not considered to be of biological significance.

Gross pathology:

At necropsy, 2 male rats showed foci or areas of lung discoloration. These are common pathological entities in Sprague-Dawley rats and are not ascribed to exposure to the test material.

Applicant's summary and conclusion

Conclusions:

Under the conditions of the study, the media lethal dose of propionaldehyde was considered to be greater than 4.6 mg/L (1930 ppm).