1,3-dimethylimidazolidin-2-one

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13 January 2005 - 28 April 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant study conducted in accordance with international guidelines.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 434 (Acute Dermal Toxicity - Fixed Dose Procedure)

Deviations:

no

GLP compliance:

yes

Test type:

fixed dose procedure

Test material

Test material information

Constituent 1

Reference substance name:

1,3-dimethylimidazolidin-2-one

EC Number:

201-304-8

EC Name:

1,3-dimethylimidazolidin-2-one

Cas Number:

80-73-9

Molecular formula:

C5H10N2O

IUPAC Name:

1,3-dimethylimidazolidin-2-one

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): 1,3-Dimethyl-2-imidazolidinone (abbreviated as “DMI”)
- Physical state: Colorless, transparent liquid
- Analytical purity: 99.8%
- Lot/batch No.: K0450033
- Stability under test conditions: Stable under storage conditions. Stability confirmed at the time of administration
- Storage condition of test material: Room temperature away from sunshine

Test animals

Species:

rabbit

Strain:

not specified

Sex:

male

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 9 weeks (at the time of start of quarantine acclimation)
- Weight at study initiation: 1.79 – 2.21 kg (at the time of grouping)
- Housing: Stainless steel or aluminium cages. 1 rabbit/cage
- Diet (e.g. ad libitum): Solid fodder (CR-1, Lot No. R1024, available from CLEA Japan, Inc.) Approx. 120 g were given once a day.
- Water (e.g. ad libitum): The rabbits were allowed to freely drink the water conforming to the water standards under the water supply law through an automatic water supply device (available from Edstrom Industries, Inc.)
- Acclimation: Yes


ENVIRONMENTAL CONDITIONS
- Temperature (°C): Actual measurement values: 20.6 – 22.5°C; allowable range: 19 - 25°C
- Humidity (%): Actual measurement values: 43 – 77%; allowable range: 30 – 70%
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12 hours/day artificial lighting (06:00 – 19:00 lamp-lighting)

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

TEST SITE
- Area of exposure: back area 12 cm x 14 cm
- Type of wrap if used: The applied area was covered with paraffin film and gauze and fixed with non-irritating tape and bandage

REMOVAL OF TEST SUBSTANCE
- Washing (if done): After the application, the applied area was wiped with gauze dipped in slightly warm water
- Time after start of exposure: 24 hours

Duration of exposure:

24 hours

Doses:

1000 and 2000mg/kg

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

- Frequency of observations and weighing: On the day of administration, 10 times a day (once before administration, once immediately after administration, once every 15 or 30 minutes after administration); 1 to 13 days after administration, twice a day; once on the day of autopsy (for Group 2, once a day from the day following the day of grouping to the day preceding the administration, in addition to the above times of administration)
- Necropsy of survivors performed: yes
- Other examinations performed: bodyweight, organ weights, other: the external surface, internal organs and tissues were visually observed.
Organs removed: Liver, kidneys (right and left) and administered section (skin of the back)

Statistics:

No statistical verification was carried out in this test.

Results and discussion

Effect levels

Dose descriptor:

LD50

Effect level:

> 2 000 other: mg/kg

Based on:

test mat.

Mortality:

During the observation period, there was no death observed.

Clinical signs:

other: No abnormal signs were observed on the day of administration. Day after administration a decrease in stool volume at 1000 and 2000 mg/kg and decreased appetite at 2000mg/kg were observed.

Gross pathology:

In autopsy, no abnormality was observed in any of the animals of any group.

Any other information on results incl. tables

In the group to which a dose of 2000 mg/kg was given, the rabbits began to show a decline in appetite and a fall in the amount of feces after one day from the administration and continued to fall in body weight until after two days from the administration. A decline in appetite and a fall in the amount of feces continued up to four days from the administration in 4 animals (in one animal, a fall in the amount of feces alone was observed two days from the administration.)

No abnormality was observed after five days from the administration to the final day of observation.

In the group to which a dose of 1000 mg/kg was given, one animal showed a decline in appetite after one day from the administration, and two animals showed a decline in appetite and a fall in the amount of feces two days after the administration. With regard to the body weight, the body weight value decreased one day after the administration, compared with the before-test value,

and there was no abnormality after three days from the administration to the final day of observation.

Applicant's summary and conclusion

Interpretation of results:

Category 5 based on GHS criteria

Conclusions:

On the basis of the results described above, it was judged under the conditions of the test that the single dermal DMI dose LD50 for rabbits was a dose higher than 2000 mg/kg.
Furthermore, the test substance was classified under “Category-5/Unclassified” according to the classification of acute toxicity under the Globally Harmonized System of Classification and Labelling of Chemicals.