Propionyl chloride

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:

other: Comparable to guideline study with acceptable restrictions.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1969

Report date:

1969

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Principles of method if other than guideline:

BASF-Test: Test was performed in principle as described in OECD Guideline 403.
The test demonstrates the toxicity of an atmosphere saturated with vapours of the volatile components of a test substance at the temperature chosen for vapour generation (20°C). 3 rats per sex were exposed sequentially to the vapours, generated by bubbling 200 l/h air through a substance column of about 5 cm above a fritted glassdisc in a glass cylinder for 8h. The documentation of clinical signs was performed over a period of 7 days. In order to verify the results, the test was repeated once.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Propionyl chloride

EC Number:

201-170-0

EC Name:

Propionyl chloride

Cas Number:

79-03-8

Molecular formula:

C3H5ClO

IUPAC Name:

propanoyl chloride

Details on test material:

- Name of test material (as cited in study report): Propionsaurechlorid
- Physical state: liquid
- Analytical purity: 95-98%

Test animals

Species:

rat

Strain:

not specified

Sex:

male/female

Details on test animals or test system and environmental conditions:

weight at beginning of the test: 190 g

Administration / exposure

Route of administration:

inhalation: vapour

Type of inhalation exposure:

not specified

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

Exposure group 1 + 2 (10 and 3 minutes exposure): Rats were exposed to the vapors, generated by bubbling 200 I/h air at 20'C through a substance column of about 5 cm above a fritted glass disc in a glass cylinder for 3 and 10 minutes.
Exposure group 3: 1.0 mg/hour test substance and 1300 L/hour.

Analytical verification of test atmosphere concentrations:

not specified

Remarks on duration:

3 and 10 minutes, 1 hour

Concentrations:

Exposure group 1 and 2: 370 mg/I (Nominal concentration calculated from mass loss of test substance and volume of air used)
Exposure group 3: 0.82 mg/l (Nominal concentration calculated from mass test substance that were dosed and volume of air used)

No. of animals per sex per dose:

1) 10 minutes: 3 males and 3 females
2) 3 minutes: 3 males and 3 females
3) 1 hour: 6 males and 6 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 7 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight

Results and discussion

Effect levels

Effect levels 1

Sex:

male/female

Dose descriptor:

other: LC92

Effect level:

4.6 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: value calculated using Haber's rule

Effect levels 2

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 0.2 mg/L air

Based on:

test mat.

Exp. duration:

4 h

Remarks on result:

other: value calculated using Haber's rule

Effect levels 3

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 2 - <= 10

Based on:

other: expert judgement: a lower acute inhalation toxicity is observed for short chain acid chlorides compared to their longer chain analogues showing higher lipophilicity and which can act deeper in the lung.

Exp. duration:

4 h

Remarks on result:

other: The actual LC50 for propionyl chloride would be in the range of the cut off values for Cat. 3 (2 mg/l-10 mg/l) (in comparison: the LC50 value for butyryl chloride is 3.6-5.7 mg/l / the LC50 value for isobutyryl chloride is 0.47-1.95 mg/l).

Mortality:

3 min exposure: In total 5 of 6 male and all 6 female animals died. 4 of 6 male and 3 of 6 female animals died 2 min after exposure. 1 male and 1 female animal died 1 hour after exposure and 2 female animals died 1 day after the exposure.
10 min exposure: 2 of 3 males and 2 of 3 female animals died immediately after 2 min of exposure.
1 hour's exposure: no lethality.

Clinical signs:

other: Immediately after the start of exposure, the animals showed attempts to escape, sever mucosal irritation and gasping. The surviving male and female animals showed cloudy cornea, dyspnea and sever nasal secretion. They were free of clinical signs of toxici

Body weight:

Normal body weight growth

Gross pathology:

Animals that died during the study: acute congestion and edema of the lung.
Animals examined at termination of the study: no abnormality.

Any other information on results incl. tables

With regard to structure activity, it can be observed that the short chain acid chlorides (e.g. propionyl or butyryl chloride (CAS number: 141-75-3)) affect more the upper tract of the respiratory tract due to their more hydrophilic properties. A lower acute inhalation toxicity is observed for these substances compared to their longer chain analogues showing higher lipophilicity and which can act deeper in the lungs (such as isobutyryl chloride (CAS number: 79-30-1)). Based on this consideration and based on the results of the study, it is estimated that the actual LC50 (vapour) for propionyl chloride would be in the range of the cut off values for a Cat. 3 acute inhalation toxicant (2 mg/l-10 mg/l) (in comparison: the LC50 value estimated for butyryl chloride is 3.6-5.7 mg/l while the LC50 value calculated for isobutyryl chloride is 0.47-1.95 mg/l).