Chemical Properties
white crystalline solid
General Description
Colorless deliquescent crystals. Mp: 45°C; bp: 260°C. Density: 1.282 g cm-3. Quite soluble in water (77 g/100 g solution at 15°C). Soluble in butanol, methyl ethyl ketone, ethyl acetate, alcohols, phenols, amines, ethers. Note: The term "CYANAMIDE(420-04-2)(420-04-2)" is also used to refer to the important compound calcium CYANAMIDE(420-04-2), which is a different chemical.
Reactivity Profile
CYANAMIDE is the amide of cyanic acid. Non-flammable but combustible (flash point: 140°C). Decomposes on warming above 49°C. Emits toxic fumes of CN-and NOx when heated to decomposition or on contact with acids or acid fumes (Hazardous Chemicals Desk Reference, p. 353 (1987)). Contact with moisture, acids or bases may cause a violent reaction at temperatures above about 40°C. Dry solid may polymerize at temperatures above 122°C. Rapid or explosive polymerization may occur during the evaporation of aqueous solutions. Reacts explosively with strong oxidizing agents and strong reducing agents. Attacks various metals (International Chemical Safety Card).
Hazard
Strong irritant to skin and mucous membranes; avoid inhalation or ingestion.
Potential Exposure
Cyanamide may be melted to give a
dimer, dicyandiamide or cyanoguanidine. At higher tem-
peratures it gives the trimer, melamine; a raw material for
melamine-form aldehyde resins.
First aid
If this chemical gets into the eyes, remove any
contact lenses at once and irrigate immediately for at least
15 minutes, occasionally lifting upper and lower lids. Seek
medical attention immediately. If this chemical contacts the
skin, remove contaminated clothing and wash immediately
with soap and water. Seek medical attention immediately.
If this chemical has been inhaled, remove from exposure,
begin rescue breathing (using universal precautions, includ-
ing resuscitation mask) if breathing has stopped and CPR if
heart action has stopped. Transfer promptly to a medical
facility. When this chemical has been swallowed, get medi-
cal attention. Give large quantities of water and induce
vomiting. Do not make an unconscious person vomit.
Shipping
UN3276 Nitriles, liquid, toxic, n.o.s., Hazard
Class: 6.1; Labels: 6.1-Poisonous materials, Technical Name
Required, Potential Inhalation Hazard (Special Provision 5).
Incompatibilities
Cyanamide may polymerize at tempera-
tures above 122℃
, or on evaporation of aqueous solutions.
Reacts with acids, strong oxidants, strong reducing agents
such as hydrides and water, causing explosion and toxic
hazard. Attacks various metals. Decomposes when heated
above 49℃
C, on contact with acids, bases, 1,2-phenylene
diamine salts; and moisture; producing toxic fumes includ-
ing nitrogen oxides and cyanides. Nitriles may polymerize
in the presence of metals and some metal compounds.
They are incompatible with acids; mixing nitriles with
strong oxidizing acids can lead to extremely violent reac-
tions. Nitriles are generally incompatible with other oxi-
dizing agents such as peroxides and epoxides. The combination of bases and nitriles can produce hydrogen
cyanide. Nitriles are hydrolyzed in both aqueous acid and
base to give carboxylic acids (or salts of carboxylic
acids). These reactions generate heat. Peroxides convert
nitriles to amides. Nitriles can react vigorously with
reducing agents. Acetonitrile and propionitrile are soluble
in water, but nitriles higher than propionitrile have low
aqueous solubility. They are also insoluble in aqueous
acids
.
Description
Cyanamide and its salts are used on various occasions,
such as in chemistry, in anti-rust solutions or in drugs
for treating alcoholism (Come).
Waste Disposal
Add excess alkaline calcium
hypochlorite with agitation. Flush to sewer after 24 hours.
Cyanamide can also be destroyed in an incinerator
equipped with afterburner and scrubber.
Definition
cyanamide: 1. An inorganic saltcontaining the ion CN22-. See calciumcyanamide. 2. A colourless crystallinesolid, H2NCN, made by the actionof carbon dioxide on hotsodamide. It is a weakly acidic compound(the parent acid of cyanamidesalts) that is soluble in water andethanol. It is hydrolysed to urea inacidic solutions.
Production Methods
The basic process for the manufacture of cyanamide comprises
four steps. The first three steps produce calcium
cyanamide: lime is made from high grade limestone;
(2) calcium carbide is manufactured from lime and coal or
coke; calcium cyanamide is produced by passing gaseous
nitrogen through a bed of calcium carbide with 1% calcium
fluorspar, which is heated to 1000–1100°C to start the
reaction—the heat source is then removed and the reaction
continues because of its strong exothermic character; and
cyanamide is manufactured from calcium cyanamide by
continuous carbonation in an aqueous medium.
Reactions
Cyanamide reacts (1) as a base with strong acids forming salts, (2) as an acid forming metallic salts, such as calcium cyanamide CaCN2. Cyanamide is formed (1) by reaction of cyanogen chloride CN·Cl plus ammonia (ammonium chloride also formed), (2) by reaction of thiourea plus lead hydroxide (lead sulfide also formed).
Health Hazard
Cyanamide is an irritant of the
eyes, mucous membranes, and skin; it is an
inhibitor of aldehyde dehydrogenase and can
cause an “antabuse” effect with ethanol
ingestion.
Cyanamide is severely irritating and
caustic to the eyes, skin, and respiratory tract.
Flammability and Explosibility
Notclassified
Agricultural Uses
Cyanamide, the trade name for calcium cyanamide, contains calcium hydroxide and carbon in small quantities as impurities. It is used as a fertilizer, the powdered form of which contains about 22% nitrogen.
Agricultural Uses
Herbicide, Plant growth regulator: A U.S. EPA restricted Use Pesticide (RUP). Not
currently approved for use in EU countries (re-submitted).
Used primarily as a plant growth regulator. Cyanamide may
be melted to give a dimer, dicyandiamide or cyanoguanidine. At higher temperatures it gives the trimer, melamine,
a raw material for melamine-formaldehyde resins.
Trade name
DORMEX®; SKW 83010®
storage
(1) Color Code—Yellow: Reactive Hazard; Storein a location separate from other materials, especially flammables and combustibles. (2) Color Code—Blue: HealthHazard/Poison: Store in a secure poison location. Prior toworking with this chemical you should be trained on itsproper handling and storage. Store in tightly closed containers in a cool well-ventilated area away from acids or acidfumes. Cyanamide can be stored in glass containers if it isstabilized with phosphoric, acetic, sulfuric, or boric acid; itattacks iron and steel, copper, and brass.
Sources of ignition, such as smoking and open flames, areprohibited where cyanamide is used, handled, or stored in amanner that could create a potential fire or explosion hazard.Wherever cyanamide is used, handled, manufactured, orstored, use explosion-proof electrical equipment and fittings.
Purification Methods
Purify it by placing ca 15g in a Soxhlet thimble and extracting exhaustively (2-3hours) with two successive portions of Et2O (400mL, saturated with H2O by shaking before use) containing two drops of 1N acetic acid. Two successive portions of Et2O are used so that the NH2CN is not heated for too long. Each extract is dried over Na2SO4 (30g), then combined and evaporated under reduced pressure. The NH2CN may be stored unchanged at 0o in Et2O solution in the presence of a trace of AcOH. Extracts from several runs may be combined and evaporated together. The residue from evaporation of an Et2O solution is a colourless viscous oil which sets to a solid and can be recrystallised from a mixture of 2 parts of *C6H6 and 1 part of Et2O. Concentrating an aqueous solution of NH2CN at high temperatures causes EXPLOSIVE polymerisation. [Kurzer & Lawson Org Synth Coll Vol IV 645 1963, Pinck & Salissbury Inorg Synth III 39 1950, Soloway & Lipschitz J Org Chem 23 613 1958.] Hygroscopic.[Beilstein 3 IV 145.]
Toxicity evaluation
Adsorption–desorption studies in soil have estimated very low
Koc values (0–6.81 ml g-1 ) indicating low adsorption and high
mobility potential of cyanamide in soil; however, soil column
leaching studies indicate that cyanamide is only slightly
mobile. Volatilization is not expected to be an important fate
and transport process based on the Henry’s law constant and
vapor pressure. When released into the air, vapor phase cyanamide
is expected to have a half-life of less than 1 day. Aerobic
biodegradation is expected to occur, with cyanamide serving as
source of nitrogen and carbon. The estimated half-life of
cyanamide from the water phase of the aquatic systems was 2.3
days for the river system and 4.3 days for the pond system,
respectively. Bioconcentration and bioaccumulation potential
is expected to be low, based on the estimated bioconcentration
factor and experimental octanol–water partition coefficient.