Cyanamide

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1973

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1973

Report date:

1973

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

yes

Remarks:

Report deficiencies: E.g. temperature of air, humidity of air, equipment for measuring temperature, humidity and particulate aerosol. No data of body weight, individual clinical signs and gross pathological findings.

Principles of method if other than guideline:

Some minor report deficiencies which are considered to have no impact on the quality of the results:
e.g. temperature of air, humidity of air, equipment for measuring temperature, humidity and particulate aerosol. No data of body weight, individual clinical signs and gross pathological findings.

GLP compliance:

no

Remarks:

The study was conducted prior to implementation of GLP.

Test type:

acute toxic class 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 (as cited in study report): Cyanamid L500
- Appearance: Clear yellowish liquid
- Analytical purity: 53 % (w/v)

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

- Source: Central Institute for the Breeding of Laboratory Animals TNO, Zeist, Netherlands
- Body weight at the study initiation was about 200 g for males and about 180 g for females

Administration / exposure

Route of administration:

other: Inhalation: mists

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Analytical verification of test atmosphere concentrations:

no

Duration of exposure:

4 h

Concentrations:

2.0 mg/ L of technical active Cyanamid L500

No. of animals per sex per dose:

5 animals per sex per dose (one dose)

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

Results and discussion

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 1 mg/L air

Exp. duration:

4 h

Remarks on result:

other: Corresponding to technical active Cyanamid L500 > 2.0 mg/L.

Mortality:

No mortalities were recorded during the study.

Clinical signs:

other: During the exposure a lumback behaviour and a rapid shallow respiration with frequent coughing and swallowing were observed. Within a few hours after exposure all animals were completely recovered and showed normal behaviour.

Body weight:

Not indicated

Gross pathology:

No visible lesions were observed at gross necropsy.

Other findings:

No other findings

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The inhalative LC50 of cyanamide was > 1 mg/L in male and female rats after 4 hour inhalation (corresponding to technical active Cyanamid L500 > 2.0 mg/L).

Executive summary:

The toxicity of Cyanamid L500 (a 50 % aqueous solution) by the inhalation route (whole-body) was investigated in five male and five female Wistar rats. The rats were exposed to the mist of technical active cyanamide in a concentration of 2.0 mg/L of air (corresponding to the highest technical attainable concentration) for four hours.

No mortalities were recorded during the study. During the exposure a lumback behaviour and a rapid shallow respiration with frequent coughing and swallowing were observed. Within a few hours after exposure all animals were completely recovered and showed normal behaviour. No visible lesions were observed at gross necropsy.

The inhalative LC50 of cyanamide was > 1 mg/L in male and female rats after 4 hour inhalation (corresponding to technical active Cyanamid L500 > 2.0 mg/L).