Cyanamide

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1988

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1988

Report date:

1988

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: U.S. EPA 40 CFR Part 158.81.2

Deviations:

not applicable

GLP compliance:

yes

Test type:

standard acute method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Cyanamide

EC Number:

206-992-3

EC Name:

Cyanamide

Cas Number:

420-04-2

Molecular formula:

CH2N2

IUPAC Name:

cyanamide

Test material form:

other: aqueous solution

Details on test material:

- Name of test material: Cyanamid L500 (50 % aqueous solution)
- Purity: 53 % (w/v)
- Appearance: Clear colourless liquid
- Lot/batch No.: 07/07/87

Test animals

Species:

rabbit

Strain:

New Zealand White

Sex:

male/female

Details on test animals or test system and environmental conditions:

The New Zealand White Rabbits were provided by Hazelton Research Products Inc., Denver Pennsylvania.

Administration / exposure

Type of coverage:

occlusive

Vehicle:

unchanged (no vehicle)

Details on dermal exposure:

The test substance was applied dermally to the shaved intact skin (approximately 10 % of the total body surface) of the test animals. The liquid test material was held in contact with the skin for a 24 hour period with impervious rubber damming.

Duration of exposure:

24 h

Doses:

530, 1060 and 2120 mg/kg bw of pure active substance Cyanamide, corresponding to 1.0, 2.0 and 4.0 mL/kg bw of 50 % aqueous Hydrogen cyanamide solution.

No. of animals per sex per dose:

5 animals per dose per sex

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight.

Results and discussion

Effect levels

Effect levels 1

Sex:

male

Dose descriptor:

LD50

Effect level:

901 mg/kg bw

Based on:

act. ingr.

Remarks on result:

other: Corresponding to 1.7 mL/kg bw of the 50 % aqueous Hydrogen cyanamide solution.

Effect levels 2

Sex:

female

Dose descriptor:

LD50

Effect level:

742 mg/kg bw

Based on:

act. ingr.

Remarks on result:

other: Corresponding to 1.4 mL/kg bw of the 50 % aqueous Hydrogen cyanamide solution.

Effect levels 3

Key result

Sex:

male/female

Dose descriptor:

LD50

Effect level:

848 mg/kg bw

Based on:

act. ingr.

Remarks on result:

other: Corresponding to 1.6 mL/kg bw of the 50 % aqueous Hydrogen cyanamide solution.

Mortality:

Mortality was observed in all dose groups, especially at mid (1060 mg/kg bw ) and high dose (2120 mg/kg bw) levels and occurred between day 1 and day 2 after treatment. No clinical observations were noted at the mid dose as all animals died on day 1.

Clinical signs:

other: Clinical signs of toxicology included tremors, ataxia, anorexia, depression and were observed at the low and high dose group. No signs of dermal irritations were noted in the low dose group, whereas all surviving animals of the high dose group showed a we

Gross pathology:

In rabbits that survived no pathologic changes at necropsy were observed. In rabbits found dead during the observation period changes mainly concerning the lung were observed (dark red lungs or dark red lung areas). In one animal of the high dose group a pale liver was noted.

Other findings:

No other findings

Any other information on results incl. tables

Table 1: Mortality in the acute dermal toxicity study in White rabbits with cyanamide

Males			Females
Dose	Mortality	Time of death	Dose	Mortality	Time of death
530 mg/kg bw	0/5	-	530 mg /kg bw	1/5	Day 1
1060 mg/kg bw	5/5	Day 1 and 2	1060 mg/kg bw	5/5	Day 2
2120 mg/kg bw	4/5	Day 2	2120 mg/kg bw	5/5	Day 2

 

Applicant's summary and conclusion

Interpretation of results:

Category 3 based on GHS criteria

Conclusions:

The acute dermal LD50 was 901 mg/kg bw in males, 742 mg/kg bw in females and 848 mg/kg bw combined for the sexes pure active substance cyanamide in rabbits (corresponding to about 1.6 mL/kg bw for the sexes combined, 1.7 mL/kg bw for males and 1.4 mL/kg bw for females of the 50 % aqueous Hydrogen cyanamide solution).

Executive summary:

The test substance Cyanamid L500 was applied dermally to the shaved intact skin of five male and five female New Zealand White rabbits per dose group. 50 % w/w hydrogen cyanamide technical solution 1.0, 2.0 and 4.0 mL/kg bw (corresponding to 530, 1060 and 2120 mg/kg bw pure active substance cyanamide) were applied. The liquid test material was held in contact with the skin for a 24 hour period with impervious rubber damming. The animals were evaluated for treatment related effects on the day of dosing and for a subsequent 14-day observation period.

Clinical signs included tremors, ataxia, anorexia, depression were observed at the low and high dose group. No signs of dermal irritations were noted in the low dose group, whereas all surviving animals of the high dose group showed a well defined erythema and a very slightly oedema on day 1. All other animals died before primary dermal irritation scoring could be performed. In rabbits that survived no pathologic changes at necropsy were observed. In rabbits found dead during the observation period changes mainly concerning the lung were observed (dark red lungs or dark red lung areas). In one animal of the high dose group a pale liver was noted.

The acute dermal LD50 was 901 mg/kg bw in males, 742 mg/kg bw in females and 848 mg/kg bw combined for the sexes pure active substance cyanamide in rabbits (corresponding to about 1.6 mL/kg bw for the sexes combined, 1.7 mL/kg bw for males and 1.4 mL/kg bw for females of the 50 % aqueous Hydrogen cyanamide solution).