Calcium cyanamide

156-62-7

Hazard Summary

Calcium cyanamide is used as a fertilizer, pesticide, and in the manufacture of other chemicals. It is
irritating to the eyes, skin, and respiratory tract in humans. Acute (short-term) inhalation exposure may
cause gastritis,rhinitis, pharyngitis, laryngitis, and tracheobronchitis. Acute oral exposure may cause a
vasomotor reaction, resulting in intense flushing of the face, upper body, and arms. Tachycardia and
hypotension have also been observed in humans following acute oral exposure. Chronic (long-term)
occupational exposure has been reported to cause chronic rhinitis with perforation of the nasal septum in
workers. EPA has not classified calcium cyanamide with respect to potential carcinogenicity.

Please Note: The main sources of information for this fact sheet are the Hazardous Substances Data Bank (HSDB)
(2), a database of summaries of peer-reviewed literature, and the Registry of Toxic Effects of Chemical
Substances (RTECS) (3), a database of toxic effects that are not peer reviewed.

Uses

•	Calcium cyanamide is used as a fertilizer, defoliant, herbicide, fungicide, and pesticide; in the manufacture
and refining of iron; and in the manufacture of calcium cyanide, melamine, and dicyandiamide. (1,2,5)

Sources and Potential Exposure

•	Occupational exposure to calcium cyanamide may occur during its manufacture and use. (1)

Assessing Personal Exposure

•	No information was located regarding the measurement of personal exposure to calcium cyanamide.

Health Hazard Information

Acute Effects:

•	Calcium cyanamide is irritating to the eyes, skin, and respiratory tract in humans. Acute inhalation
exposure may cause gastritis, rhinitis, pharyngitis, laryngitis, and tracheobronchitis. (1,2)

•	Acute oral exposure of humans may cause a vasomotor reaction, resulting in intense localized
erythematous flushing of the face, upper body, and arms, with headache, dizziness, fatigue, vertigo,
congestion of the mucosa, nausea, and vomiting also reported. (1,2)

•	Tachycardia and hypotension have also been observed in humans following acute oral exposure. (1,2)

•	Peripheral neuropathy was reported in one case of acute oral exposure in a human. (2)

•	Effects on liver enzymes have been reported in rats acutely exposed by ingestion. (2)

•	Acute animal tests in rats, mice, and rabbits have demonstrated calcium cyanamide to

have moderate to high acute toxicity from oral exposure and high acute toxicity from dermal exposure. (3)

Chronic Effects (Noncancer):

•	Chronic occupational exposure has been reported to cause chronic rhinitis with perforation of the nasal
septum in workers. (1,2)

•	Chronic dermal exposure may result in slow-healing dermal ulceration in humans. (1,2)


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EPA has not established a Reference Concentration (RfC) or a Reference Dose (RfD) for calcium cyanamide.
(4)

Reproductive /Developmental Effects:

•	No information is available on the reproductive or developmental effects of calcium cyanamide in humans
or animals.

Cancer Risk:

•	No information is available on the carcinogenic effects of calcium cyanamide in humans.

•	EPA has not classified calcium cyanamide with respect to potential carcinogenicity.

•	A formulation of calcium cyanamide in the diet was not found to be carcinogenic in a two-year National
Toxicology Program study in rats or mice. (4)

Physical Properties

•	The chemical formula for calcium cyanamide is CCaN^, and its molecular weight is 80.1 1 g/mol. (5)

•	Commercial grades of calcium cyanamide occur as grayish-black lumps of powder. Pure calcium
cyanamide occurs as glistening hexagonal crystals that are insoluble in water. (2,5)

•	The odor threshold for calcium cyanamide has not been established.

Conversion Factors:

3	3

To convert concentrations in air (at 2 5°C) from ppm to mg/m : mgjm = (ppm) x (molecular weight of the
compound)/(24.45). For^calcium cyanamide: 1 ppm = 3.28 mg/m . To convert concentrations in air from
|jg/m to mg/m : mg/m = (pg/m ) x (1 mg/1,000 |jg).

Health Data from Inhalation Exposure


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Calcium Cyanamide

10

0.01

Health numbers"

Regulatory, advisory
numbers'*

-



-



NIOSH REL A<
(0.5 mg/m5)

IGIH TLV

-







ACGIH TLV—American Conference of Governmental and Industrial Hygienists' threshold limit value expressed as a
time-weighted average; the concentration of a substance to which most workers can be exposed without adverse
effects.

NIOSH REL—National Institute of Occupational Safety and Health's recommended exposure limit; NIOSH-
recommended exposure limit for an 8- or 1 0-h time-weighted-average exposure and/or ceiling.

The health and regulatory values cited in this factsheet were obtained in December 1999.

a

Health numbers are toxicological numbers from animal testing or risk assessment values developed by EPA.

b

Regulatory numbers are values that have been incorporated in Government regulations, while advisory numbers
are nonregulatory values provided by the Government or other groups as advice. NIOSH and ACGIH numbers are
advisory.

Summary created in April 1 992, updated in January 2000.

References

1.	M. Sittig. Handbook of Toxic and Hazardous Chemicals and Carcinogens. 2nd ed. Noyes Publications, Park
Ridge, NJ. 1985.

2.	U.S. Department of Health and Human Services. Hazardous Substances Data Bank (HSDB, online database).
National Toxicology Information Program, National Library of Medicine, Bethesda, MD. 1 993.

3.	U.S. Department of Health and Human Services. Registry of Toxic Effects of Chemical Substances (RTECS,
online database). National Toxicology Information Program, National Library of Medicine, Bethesda, MD.


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1993.

4.	National Toxicology Program (NTP). Bioassay of Calcium Cyartamide (CAS No. 1 56-62-7) for Possible
Carcinogenicity. TR-1 63. 1 979.

5.	The Merck Index. An Encyclopedia of Chemicals, Drugs, and Biologicals. 1 1 th ed. Ed. S. Budavari. Merck and
Co. Inc., Rahway, NJ. 1 989.

6.	National Institute for Occupational Safety and Health (NIOSH). Pocket Guide to Chemical Hazards. U.S.
Department of Health and Human Services, Public Health Service, Centers for Disease Control and
Prevention. Cincinnati, OH. 1 997.

7.	American Conference of Governmental Industrial Hygienists (ACGIH). 1 999 TLVs and BEIs. Threshold Limit
Values for Chemical Substances and Physical Agents. Biological Exposure Indices. Cincinnati, OH. 1 999.


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