Calcium cyanamide

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1978

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1978

Report date:

1978

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

Deviations:

not specified

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Calcium cyanamide

EC Number:

205-861-8

EC Name:

Calcium cyanamide

Cas Number:

156-62-7

Molecular formula:

CN2.Ca

IUPAC Name:

calcium cyanoazanediide

impurity 1

Reference substance name:

Calcium oxide

EC Number:

215-138-9

EC Name:

Calcium oxide

Cas Number:

1305-78-8

Molecular formula:

CaO

IUPAC Name:

oxocalcium

impurity 2

Reference substance name:

Carbon

EC Number:

231-153-3

EC Name:

Carbon

Cas Number:

7440-44-0

Molecular formula:

C

IUPAC Name:

carbon

impurity 3

Reference substance name:

Hematite (Fe2O3)

EC Number:

215-275-4

EC Name:

Hematite (Fe2O3)

Cas Number:

1317-60-8

Molecular formula:

Fe2O3

IUPAC Name:

diiron oxide

impurity 4

Reference substance name:

Urea

EC Number:

200-315-5

EC Name:

Urea

Cas Number:

57-13-6

Molecular formula:

CH4N2O

IUPAC Name:

urea

impurity 5

Reference substance name:

Silicon dioxide

EC Number:

231-545-4

EC Name:

Silicon dioxide

Cas Number:

7631-86-9

Molecular formula:

O2Si

IUPAC Name:

dioxosilane

impurity 6

Reference substance name:

Trisilicon tetranitride

EC Number:

234-796-8

EC Name:

Trisilicon tetranitride

Cas Number:

12033-89-5

Molecular formula:

N4Si3

IUPAC Name:

trisilicon tetranitride

impurity 7

Reference substance name:

Calcium dihydroxide

EC Number:

215-137-3

EC Name:

Calcium dihydroxide

Cas Number:

1305-62-0

Molecular formula:

CaH2O2

IUPAC Name:

calcium dihydroxide

impurity 8

Reference substance name:

Aluminium oxide

EC Number:

215-691-6

EC Name:

Aluminium oxide

Cas Number:

1344-28-1

Molecular formula:

Al2O3

IUPAC Name:

aluminium oxide

impurity 9

Reference substance name:

Cyanoguanidine

EC Number:

207-312-8

EC Name:

Cyanoguanidine

Cas Number:

461-58-5

Molecular formula:

C2H4N4

IUPAC Name:

2-cyanoguanidine

impurity 10

Reference substance name:

Calcium acetylide

EC Number:

200-848-3

EC Name:

Calcium acetylide

Cas Number:

75-20-7

Molecular formula:

C2Ca

IUPAC Name:

calcium ethynediide

impurity 11

Reference substance name:

unknown

IUPAC Name:

unknown

Test material form:

solid: particulate/powder

Details on test material:

Kalkstickstoff (calcium cyanamide, technical grade)

Test animals

Species:

rat

Strain:

other: Wistar derived, albino CPB-rats

Sex:

male/female

Details on test animals or test system and environmental conditions:

A group of five male and five female SPF-rated, Wistar derived, albino CPB-rats, 9 weeks old, was used. The average weight of the males was 223 g, that of the females 153 g. After exposure the rats were returned to their living cages and provided with stock diet and tap water ad libitum during an observation period of 14 days.

Administration / exposure

Route of administration:

inhalation: dust

Type of inhalation exposure:

whole body

Vehicle:

other: unchanged (no vehicle)

Details on inhalation exposure:

The powdered substance was continuously dispersed in air by means of a "Wright" Dust Feed Mechanism at a maximum rate of 17 g/m3. The dustladen air was passed into a 1.5 m3 stainless steel exposure chamber in which the experimental animals were housed individually in wire-screen cages. The animals could be observed continuously through the hard glass entrance door. The temperature and relative humidity inside the exposure chamber were 23°C and 45-50% respectively.

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

The concentration of the dispersed Kalkstickstoff was determined gravimetrically by passing a measured amount of the test atmosphere through a glassfibre filter. Particle size determinations and counts were carried out in samples taken from the atmosphere in the chamber with a cascade impactor.
The group of the five male and female was exposed to a dispersion of Kalkstickstoff in air at a maximum attainable concentration of 155 mg/m3. Particle size determination and particle counts in air revealed a 99 % particle size range of 0.8 - 3.3 µm.

No. of animals per sex per dose:

5

Control animals:

no

Details on study design:

no further details given

Statistics:

not reported

Results and discussion

Preliminary study:

no preliminary study

Effect levels

Key result

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 155 mg/m³ air (analytical)

Exp. duration:

4 h

Mortality:

no mortality

Clinical signs:

other: During the first 45 minutes of the exposure period the rats were quiet and their behaviour was normal. During the next two hours the rats were slightly restless, but these signs of irritation gradually disappeared. The last hour of the exposure period all

Body weight:

not reported

Gross pathology:

not reported

Other findings:

none

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

It was concluded that the 4-hour LC50 of Kalkstickstoff was higher than 155 mg/m3 of air.

Executive summary:

The group of the five male and female was exposed to a dispersion of Kalkstickstoff in air at a maximum attainable concentration of 155 mg/m3. Particle size determination and particle counts in air revealed a 99 % particle size range of 0.8 - 3.3 µm.

During the first 45 minutes of the exposure period the rats were quiet and their behaviour was normal. During the next two hours the rats were slightly restless, but these signs of irritation gradually disappeared. The last hour of the exposure period all rats were completely quiet and seemed to be asleep. No mortality and no signs of intoxication were observed.

The results of the present acute inhalation toxicity study lead to the conclusion that the 4 -hour LC50 of Kalkstickstoff is higher than 155 mg/m3 of air.