Registration Dossier

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

Referenceopen allclose all

Reference Type:
publication
Title:
Unnamed
Year:
1974
Report Date:
1974
Reference Type:
study report
Title:
Unnamed
Year:
1970
Report Date:
1970

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
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

Reference
Name:
Unnamed
Type:
Constituent
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 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:
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.