2-methylbutyraldehyde

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

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 (only 4 animals per group, occlusive wrapping, limited reporting)

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Unnamed

Year:

1974

Report date:

1974

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1970

Report date:

1970

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 402 (Acute Dermal Toxicity)

Deviations:

yes

Remarks:

: only 4 animals per group, occlusive wrapping, limited reporting

Principles of method if other than guideline:

Pre-guideline study, but method used is similar to OECD TG 402.

GLP compliance:

no

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-methylbutyraldehyde

EC Number:

202-485-6

EC Name:

2-methylbutyraldehyde

Cas Number:

96-17-3

Molecular formula:

C5H10O

IUPAC Name:

2-methylbutanal

Details on test material:

- Name of test material (as cited in study report): 2-Methylbutyraldehyde
- No further information on test substance

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: no data
- Age at study initiation: 3 to 5 month
- Weight at study initiation: 2.5 - 3.5 kg

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: part of the trunk
- % coverage: no data
- Type of wrap if used: impervious plastic film
- Restraining of animals: animals are immobilized during the 24 h exposure period

REMOVAL OF TEST SUBSTANCE
- Washing (if done): excess fluid is removed
- Time after start of exposure: 24 hours

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): no data

Duration of exposure:

24 hours

Doses:

4.0, 8.0, and 16.0 mL/kg bw (3213, 6426, and 12853 mg/kg bw)

No. of animals per sex per dose:

4 male rabbits per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: no data
- Necropsy of survivors performed: no data
- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other: no data

Statistics:

LD50 values were calculated by the method of Thompson (1947, Bacteriol. Rev. 11, 115) using the tables of Weil (1952, Biometrics 8, 249.

Results and discussion

Effect levels

Sex:

male

Dose descriptor:

LD50

Effect level:

5 400

95% CL:

3 535 - 8 274

Remarks on result:

other: values are converted from mL/kg bw as reported by authors.

Mortality:

Concentration Mortality
3213 mg/kg bw 0 / 4
6426 mg/kg bw 3 / 4
12853 mg/kg bw 4 / 4

Clinical signs:

other: Erythema, edema, necrosis

Gross pathology:

congestion of lungs, livers, kidneys and spleens of victims;
stomachs opaque and livers mottled.

Any other information on results incl. tables

The acute dermal LD50 was reported as 6.73 mL/kg bw (4.40 - 10.3 mL/kg bw). The figures in parentheses show the limits of ± 1.96 standard deviations. Using a density of 0.8033 g/mL (Sect. 4.4), the LD50 calculates to 5400 mg/kg bw (3535 - 8274 mg/kg bw).

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The acute dermal LD50 was 5400 mg/kg bw in male rabbits. No classifcation required according to EU legislation.

Executive summary:

The acute dermal toxicity of 2-methylbutyraldehyde (2-methylbutanal) was determined in groups of 4 male albino New Zealand rabbits receiving graduate single doses of test substance per group (3213, 6426, and 12853 mg/kg bw). The exposure time was 24 hours followed by an observation period of 14 days. From mortality data, the LD50 and a range of ± 1.96 SD was calculated according to the method of Thomson (1947).

 

The acute dermal LD50 for 2-methylbutyaldehyde was determined to be 5400 mg/kg bw in rabbits (Carpenter, 1974).

 

Overall, the study was conducted similar to OECD test guideline 402 with some restrictions (only 4 animals per group, occlusive wrapping, limited reporting). The deviations from the test guideline are considered not to invalidate the result.