Cyclohexanone oxime

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

30. Jan 1979 to 28. Feb 1979

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Similar to guideline OECD 401 with acceptable restrictions, limited documentation

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1979

Report date:

1979

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: EPA guideline (not further specified)

GLP compliance:

not specified

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Cyclohexanone oxime

EC Number:

202-874-0

EC Name:

Cyclohexanone oxime

Cas Number:

100-64-1

Molecular formula:

C6H11NO

IUPAC Name:

cyclohexanone oxime

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): cyclohexanone oxime
- Substance type: white crystalline powder
- Storage condition of test material: at room temperature

Test animals

Species:

rat

Strain:

Fischer 344

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: CHarles River Breeding Laboratory, Wilmington, USA
- Weight at study initiation: 145-236 g (males) and 138-163 g (females)
- Fasting period before study: overnight
- Housing: groups of two
- Diet (ad libitum): Purina laboratory chow
- Water (ad libitum): source not stated
- Acclimation period: 7 days

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

not specified

Details on oral exposure:

MAXIMUM DOSE VOLUME APPLIED: 5000 mg/kg

Doses:

males: 562, 794, 1000, 1410, 1590, 2000 and 5000 mg/kg
females: 398, 631, 1000, 2000 and 5000 mg/kg

No. of animals per sex per dose:

10

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:clinical observations immediately after dosing, then after 1 and 4 h, and twice daily thereafter
- Necropsy of survivors performed: yes

Statistics:

Probit analysis according to Finney

Results and discussion

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

LD50

Effect level:

1 765.01 mg/kg bw

Based on:

test mat.

95% CL:

1 632 - 1 908.62

Remarks on result:

other: Acc. to study report: data obtained excluding the results of the 1000 mg/kg group; including this group the LD50 was 1758.94 (95% CI: 1374.74-2250.52) mg/kg

Effect levels 2

Sex:

female

Dose descriptor:

LD50

Effect level:

882.82 mg/kg bw

Based on:

test mat.

95% CL:

725.88 - 1 073.69

Mortality:

Mortality in males:
562 mg/kg: 0
794 mg/kg: 0
1000 mg/kg: 3
1410 mg/kg: 0
1590 mg/kg: 3
2000 mg/kg: 8
5000 mg/kg: 10

Mortality in females:
398 mg/kg: 0
631 mg/kg: 2
1000 mg/kg: 6
2000 mg/kg: 10
5000 mg/kg: 10

Clinical signs:

Surviving animals: transient slight to marked depression, rough hair coat, salivation, urine stains, ataxia in all dose groups for 1 - 4 h after administration (up to 2 days at higher doses)
labored respiration, prostration before death

Body weight:

not recorded

Gross pathology:

Discoloration of the spleen was noted in ten male rats dosed at 794 mg/kg of body weight, and in seven males dosed a t the 1590 mg/kg level. Discoloration of the stomach and/or intestines was observed in two males dosed a t the1000 mg/kg level, two males dosed at the 1590 mg/kg level, and four females dosed at 2000 mg/kg of body weight. Dark fluid was observed in the stomach and/or intestines of one male dosed a t 1000 mg/kg of body weight, three males dosed at the 1590 mg/kg level, one female dosed at the 631 mg/kg level, and three females dosed at the 1000 mg/kg level. Compound was noted in the stomach and/or intestines of two males dosed at the 1590 mg/kg level, in seven males and nine females dosed at the 2000 mg/kg level, and in all ten males and females dosed a t the 5000 mg/kg level.

Applicant's summary and conclusion

Interpretation of results:

Toxicity Category IV

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Under the conditions of this study the test substance the LD50 in rats was 883 mg/kg bw for females and 1765 mg/kg bw for males. Therefore the substance has to be classified as harmful if swallowed according to Regulation (EC) No 1272/2008

Executive summary:

The test substance was evaluated for acute oral toxicity in male and female Fischer 344 rats in a study performed according to EPA guidelines (similar to guideline OECD 401). Groups of 10 animals per sex were exposed to 562, 794, 1000, 1410, 1590, 2000 or 5000 mg/kg (males) or 398, 631, 1000, 2000 or 5000 mg/kg (females). After exposure the animals were observed for 14 days. Surviving animals showed transient slight to marked depression, rough hair coat, salivation, urine stains, and ataxia in all dose groups for 1 - 4 h after administration (up to 2 days at higher doses). Labored respiration and prostration was evident before death. Based upon the findings of this study, the acute oral LD50 was calculated to be 1765.01 and 882.82 mg/kg bw, with 95% confidence limits for males from 1632.20 to 1908.62 mg/kg bw and for females from 725.88 to 1073.69 mg/kg bw.