Cyanamide

Nitrogen Compounds -> Cyanamides

Flammable agents - 3rd degree

Herbicides, Plant Growth Regulators

Active substance -> EU Pesticides database: Not approved

Environmental transformation -> Pesticides (parent, predecessor)

1.28 (NIOSH, 2024) - Denser than water; will sink

1.282 g/cu cm at 20 °C

Relative density (water = 1): 1.28

1.28

1.282 @ 20°C

1.28

Orthorhombic, elongated, six-sided tablets from dimethyl phthalate

Crystallizes from a variety of solvents as somewhat unstable, colorless, orthorhombic, deliquescent crystals.

Deliquescent crystals

Cyanamide forms colorless, orthorhombic crystals or long transparent needles (from water), large platelike crystals when allowed to crystallize spontaneously from water, and crystals from dimethyl phthalate solution.

78 % at 59 °F (NIOSH, 2024)

In butanol 28.8; ethyl acetate 42.4, methyl ethyl ketone 50.5 (all g/100 g at 20 °C); sol in phenols, amines, ethers, ketones; very sparingly soluble in benzene, halogenated hydrocarbons; practically insoluble in cyclohexane.

Slightly soluble in carbon disulfide

Cyanamide is completely soluble in water at 43 °C and has a minimum solubility at -15 °C; highly soluble in polar organic solvents, such as alcohols, ethers, esters, nitriles and amides, but less soluble in nonpolar solvents like saturated, halogenated, or aromatic hydrocarbons. Ketones are not recommended as solvents for cyanamide, because they tend to react under certain circumstances.

In chloroform 2.4 g/kg, 20 °C

286 °F (NIOSH, 2024)

286 °F; 141 °C (closed cup)

141 °C

286 °F

286 °F

500 °F at 760 mmHg (Decomposes) (NIOSH, 2024)

140 °C at 19 mm Hg

Boiling point at 19 mm Hg is 140 °C

at 0.067kPa: 83 °C

500 °F (decomposes)

When heated to decomposition ... it emits toxic fumes of cyanide and nitroxides.

260 °C

Danger

H301: Toxic if swallowed [Danger Acute toxicity, oral]

P203, P260, P261, P262, P264, P264+P265, P270, P272, P273, P280, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P318, P319, P321, P330, P333+P317, P361+P364, P362+P364, P363, P405, and P501 (click each P-code to see the statement)

Danger

H301+H311 (53.2%): Toxic if swallowed or in contact with skin [Danger Acute toxicity, oral; acute toxicity, dermal]

P203, P260, P261, P262, P264, P264+P265, P270, P272, P273, P280, P301+P316, P301+P330+P331, P302+P352, P302+P361+P354, P304+P340, P305+P351+P338, P305+P354+P338, P316, P317, P318, P319, P321, P330, P332+P317, P333+P317, P337+P317, P361+P364, P362+P364, P363, P405, and P501 (click each P-code to see the statement)

Chemical: Cyanamide

Commission Regulation (EC) No 33/2008

Cyanamide is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Cyanamide are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Hydrogen cyanamide (Cyanamide) is listed in the dataset of EPA Human Health Benchmarks for Pesticides under the Safe Drinking Water Act (40 eCFR 141)

2008/745

Status: Active Update: 03-11-2022 https://echa.europa.eu/registration-dossier/-/registered-dossier/15823

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

Combustible only at increased temperature. Gives off irritating or toxic fumes (or gases) in a fire.

The TLV basis for cyanamide is skin and eye irritation; May cause antabuse-like effect in exposed workers who ingest alcohol; [ACGIH] Allergic contact dermatitis has been reported. [Allergic contact dermatitis from cyanamide: report of 3 cases. Goday Bujan JJ, et al. Contact Dermatitis. 1994 Nov;31(5):331-2. No abstract available. Abstract in NIOSHTIC # 192164] Can cause liver injury after ingestion; [HSDB] Danger of skin sensitization; [MAK]

New Active Ingredients ... includes chemicals not previously registered as pesticides, as well as pesticide active ingredients initially registered after November 1, 1984 and that currently have active product registrations. By law, these pesticides must meet new safety standards, such as those described in the Food Quality Protection Act of 1996 and, if new safety standards are met, will be reviewed again on a 15-year cycle. Hydrogen Cyanamide is designated by EPA as a New Pesticide Active Ingredient. Active Ingredient Number: 014002; Type of Pesticide: Conventional: Plant growth regulator; Use Site: Food use; Year: 1993.

The USEPA has published the Hydrogen Cyanamide (Cyanamide) Final Work Plan Registration Review - May 2008 in Docket EPA-HQ-OPP-2007-1014-0008. This Work Plan announces EPA's intention to conduct a comprehensive ecological risk assessment, including an endangered species assessment for all cyanamide uses and to complete a drinking water assessment. To date, the assessments have not been posted.

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).

Excerpt from ERG Guide 154 [Substances - Toxic and/or Corrosive (Non-Combustible)]:

Use carbon dioxide, dry powder, dry sand, water spray. Combat fire from a sheltered position.

Fresh air, rest. Seek medical attention if you feel unwell.

Remove contaminated clothes. Rinse skin with plenty of water or shower. Refer for medical attention .

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth. Give one or two glasses of water to drink. Do NOT induce vomiting. Refer for medical attention .

Excerpt from NIOSH Pocket Guide for Cyanamide:

(General first aid procedures)

Separated from food and feedstuffs and incompatible materials. See Chemical Dangers. Cool. Store at maximum 20 °C, never exceed 30 °C. Dry. Well closed. Keep in a well-ventilated room. Store only if stabilized. Store in stainless steel, polyethylene or polypropylene.

Use dry chemical or CO2 extinguishers. Containers may explode in fire. If material or contaminated runoff enters waterways, notify downstream users or potentially contaminated waters. Notify local health and fire officials and pollution control agencies. From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors or shows any signs of deforming), withdraw immediately to a secure position ... The only respirators recommended for fire fighting are self-contained breathing apparatuses that have full facepieces and are operated in a pressure-demand or other positive-pressure mode.

The commercial 50% solution produced by Degussa AG is stabilized by a special buffer system to a pH between 4.0 and 4.6. Typically, it contains less than 1.5 % dicyandiamide, less than 0.5% urea, and less than 0.1 % thiourea. This solution is stable for at least 3 months if stored at a temperature below 20 °C. Prolonged storage leads to an increase in the pH and thus to instability of the solution. If a pH of 5.2 has been reached, the product should be used quickly, above pH 5.5 it should be discarded immediately by mixing it with at least the double volume of water. Otherwise, a thermal runaway reaction leading to temperatures above 100 °C and potential bursting of the container may occur.

The commercial crystalline Cyanamide F1000 from Degussa AG contains a special stabilizer system to ensure safe handling and transportation. It can be stored at least for 3 months at or below 20 °C. Temperatures above 40 °C must be avoided in any case.

Store in tightly closed containers in a cool well-ventilated area away from acids or acid fumes. Cyanamide can be stored in glass containers if it is stabilized with phosphoric, acetic, sulfuric, or boric acid; it attacks iron and steel, copper and brass. Sources of ignition, such as smoking and open flames, are prohibited where cyanamide is used, handled, or stored in a manner that could create a potential fire or explosion hazard. Wherever cyanamide is used, handled, manufactured, or stored, use explosion-proof electrical equipment and fittings.

Soln can be stored in glass, provided they are stabilized with phisphoric, acetic, sulfuric, or boric acid.

Solid is stored in a cool, dry, place. Liquid is stored in pH4 added with phosphoric acid, sulfuric acid, or boric acid.

Spill handling: evacuate persons not wearing protective equipment from area of spill or leak until clean-up is complete. Remove all ignition sources. Ventilate area of spill or leak. Collect powdered material in the most convenient and safe manner and deposit in sealed containers. Absorb liquids in vermiculite, dry sand, earth, peat, carbon, or a similar material and deposit in sealed containers. It may be necessary to contain and dispose of this chemical as a hazardous waste. Keep cyanamide out of a confined space, such as a sewer, because of the possibility of an explosion, unless the sewer is designed to prevent the build-up of explosive concentrations. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Contact your Department of Environmental Protection or your regional office of the federal EPA for specific recommendations.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

Personal protection: complete protective clothing including self-contained breathing apparatus. Do NOT let this chemical enter the environment. Vacuum spilled material with specialist equipment. Carefully collect remainder. Then store and dispose of according to local regulations.

The worker should immediately wash the skin when it becomes contaminated.

Work clothing that becomes wet or significantly contaminated should be removed and replaced.

Workers whose clothing may have become contaminated should change into uncontaminated clothing before leaving the work premises.

Local exhaust or breathing protection.

For more Preventive Measures (Complete) data for Cyanamide (8 total), please visit the HSDB record page.

Systemic absorption after taking alc causes nausea, headache, vertigo, fall in blood pressure, & transitory intense redness of face.

Rats fed ethanol (150 mL/L) for 3 mo & diet contaminated with calcium cyanamide showed 2-fold higher activity of low km acetaldehyde dehydrogenase in liver, higher rate of alc elimination & 2-3 times lower acetaldehyde levels in blood during alc elimination.

Blood pressure response after alc admin was studied in relation to blood acetaldehyde levels in rats pretreated with cyanamide. Cyanamide inhibited low-km aldehyde dehydrogenase in liver & caused & incr acetaldehyde level in blood.

Cyanamide reacted with amino & thiol groups to form guanidino & isothiouronium cmpd respectively under physiological conditions. Possible mode of action of cyanamide on alcohol metabolism are discussed.

LD50 Colinus virginianus (Bobwhite quail) 173 mg/kg

LD50 Honey bee oral > 36.2 ug a.i./bee

LC50; Species: Anas platyrhynchos (Mallard duck); Concentration: > 5000 ppm for 8 days /Conditions of bioassay not given/

LC50; Species: Colinus virginianus (Bobwhite quail); Concentration: > 5000 ppm for 8 days /Conditions of bioassay not given/

For more Ecotoxicity Values (Complete) data for Cyanamide (17 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), estimated Koc values of 4.7 and 7.3(SRC), determined from a structure estimation method(2) and a log Kow of -0.82(3) with a regression-derived equation(2), respectively, indicate that cyanamide is expected to have very high mobility in soil(SRC). Volatilization of cyanamide from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.66X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 3.75X10-3 mm Hg(3), and water solubility, 7.8X10+5 mg/L(3). In soil, cyanamide is converted to nitrogenous compounds which are rapidly taken up(3). In aqueous conditions, cyanamide decomposes by hydrolysis to urea and by dimerization to dicyanamide(4,5). Cyanamide does not absorb at wavelengths >290 nm(4) and therefore is not expected to be susceptible to direct photolysis on sunlit soil or plant(SRC).

AQUATIC FATE: Based on a classification scheme(1), estimated Koc values of 4.7 and 7.3(SRC), determined from a structure estimation method(2) and a log Kow of -0.82(3) with a regression-derived equation(2), respectively, indicate that cyanamide is not expected to adsorb to suspended solids and sediment(SRC). Volatilization of cyanamide from water surfaces is not expected(4) given an estimated Henry's Law constant of 2.66X10-10 atm-cu m/mole(SRC), derived from its vapor pressure, 3.75X10-3 mm Hg(3), and water solubility, 7.8X10+5 mg/L(3). Cyanamide decomposes in water by hydrolysis to urea in acidic conditions and by dimerization to dicyanamide in alkaline conditions(5,6). Cyanamide does not absorb at wavelengths >290 nm(5) and therefore is not expected to be susceptible to direct photolysis on sunlit water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), cyanamide, which has a vapor pressure of 3.75X10-3 mm Hg at 20 °C(2), will exist solely as a vapor in the ambient atmosphere. The rate constant for the vapor-phase reaction of cyanamide with photochemically-produced hydroxyl radicals can not be estimated; therefore, the half-life for this reaction in the atmosphere can not be estimated(SRC). Cyanamide does not absorb at wavelengths >290 nm(4) and therefore is not expected to be susceptible to direct photolysis by sunlight(SRC).

The substance can be absorbed into the body by inhalation of its aerosol, through the skin and by ingestion.

inhalation, skin absorption, ingestion, skin and/or eye contact

Organic nitriles decompose into cyanide ions both in vivo and in vitro. Consequently the primary mechanism of toxicity for organic nitriles is their production of toxic cyanide ions or hydrogen cyanide. Cyanide is an inhibitor of cytochrome c oxidase in the fourth complex of the electron transport chain (found in the membrane of the mitochondria of eukaryotic cells). It complexes with the ferric iron atom in this enzyme. The binding of cyanide to this cytochrome prevents transport of electrons from cytochrome c oxidase to oxygen. As a result, the electron transport chain is disrupted and the cell can no longer aerobically produce ATP for energy. Tissues that mainly depend on aerobic respiration, such as the central nervous system and the heart, are particularly affected. Cyanide is also known produce some of its toxic effects by binding to catalase, glutathione peroxidase, methemoglobin, hydroxocobalamin, phosphatase, tyrosinase, ascorbic acid oxidase, xanthine oxidase, succinic dehydrogenase, and Cu/Zn superoxide dismutase. Cyanide binds to the ferric ion of methemoglobin to form inactive cyanmethemoglobin. (L97)

Cough. Shortness of breath.

MAY BE ABSORBED! Redness. Pain.

Redness. Pain.

Burning sensation. Sore throat. Abdominal pain.

irritation eyes, skin, respiratory system; eye, skin burns; miosis, salivation, lacrimation (discharge of tears), twitching; Antabuse-like effects

Using a structure estimation method based on molecular connectivity indices(1), the Koc of cyanamide can be estimated to be 4.7(SRC). The Koc of cyanamide can also be estimated as 7.3(SRC), using a log Kow of -0.82(2) and a regression-derived equation(1). According to a classification scheme(3), these estimated Koc values suggest that cyanamide is expected to have very high mobility in soil.

New Active Ingredients ... includes chemicals not previously registered as pesticides, as well as pesticide active ingredients initially registered after November 1, 1984 and that currently have active product registrations. By law, these pesticides must meet new safety standards, such as those described in the Food Quality Protection Act of 1996 and, if new safety standards are met, will be reviewed again on a 15-year cycle. Hydrogen Cyanamide is designated by EPA as a New Pesticide Active Ingredient. Active Ingredient Number: 014002; Type of Pesticide: Conventional: Plant growth regulator; Use Site: Food use; Year: 1993.

The USEPA has published the Hydrogen Cyanamide (Cyanamide) Final Work Plan Registration Review - May 2008 in Docket EPA-HQ-OPP-2007-1014-0008. This Work Plan announces EPA's intention to conduct a comprehensive ecological risk assessment, including an endangered species assessment for all cyanamide uses and to complete a drinking water assessment. To date, the assessments have not been posted.

Cyanide was detected as a product of cyanamide oxidation by bovine liver catalase in vitro under conditions that also produced an active aldehyde dehydrogenase (AlDH) inhibitor. Cyanide formation was directly related to both cyanamide and catalase concentrations and was also dependent on incubation time. The apparent Km for this reaction was 172 microM. Cyanide formation was blocked by ethanol, a known substrate for catalase Compound I. The toxic effects of cyanamide in the dog, a species with limited capacity to conjugate cyanamide by N-acetylation, may be causally related to enhancement of this catalase-mediated pathway for cyanamide metabolism.

The main urinary metabolite of hydrogen cyanamide (cyanamide) in rat and man is acetylcyanamide (n-acetylcyanamide). An analytical method was developed to determine acetylcyanamide in the urine with a limit of quantification of <10 ug/l (mean recovery 96.1% using spikes of 20 ug/l; relative standard deviation < 4%. This methodology is based upon ion chromatography using column-switch techniques and UV detection. It could be demonstrated that in rats an average of 45.6% of oral applied cyanamide (10 mg/kg) was excreted in the urine as acetylcyanamide. In male human volunteers a mean of 40% of oral admin cyanamide (mean dose 0.25 mg/kg body weight) was excreted via the urine as acetylcyanamide. The same group of volunteers participated in skin absorption study with dermal application of the above cyanamide dose onto a skin surface area of 32 sq cm. Within an application period of 6 hr an average cyanamide quantity of 2.3 mg, was available for skin absorption. A mean portion of 7.7% of this quantity was found as acetylcyanamide in the urine of the participants. Findings from literature state that cyanamide is metabolized in vitro to cyanide. According to examinations performed in vivo, however, such a metabolic pathway seems to be irrelevant for man. In comparisons with the control values there was no significant incr of both the cyanide concn in the blood and the thiocyanate concentrations in the urine of the above volunteers after the described oral cyanamide admin.

Organic nitriles are converted into cyanide ions through the action of cytochrome P450 enzymes in the liver. Cyanide is rapidly absorbed and distributed throughout the body. Cyanide is mainly metabolized into thiocyanate by either rhodanese or 3-mercaptopyruvate sulfur transferase. Cyanide metabolites are excreted in the urine. (L96)

A pharmacokinetic and dynamic study of cyanamide, an inhibitor of aldehyde dehydrogenase (ALDH) used as an adjuvant in the aversive therapy of chronic alcoholism, has been carried out in man after oral administrations. ... Blood ALDH activity were estimated after oral administration of 0.3, 1 and 1.5 mg/kg of cyanamide. One i.v. administration of 1 mg/kg was performed in order to determine the absolute bioavailability and the main pharmacokinetic parameters. Elimination half life and total plasma clearance values were 51.7 8.8 min and 14.4 2.7 mL/kg/min respectively. After oral administrations of 0.3, 1 and 1.5 mg/kg a rapid absorption rate was estimated with a Tmax values range of 10.5 to 15.5 min. The extent of absorption was not complete, oral bioavailability being 53%, 70% and 81% respectively. The presence of a first pass-effect is suggested. The inhibitory activity of cyanamide on blood ALDH reached the maximum value 4 hr after its administration and decreased progressively throughout six days period. The cyanamide plasma levels time course did not correlated with the pharmacodynamic time course responses.

Used in the organic synthesis of dicyandiamide in melamine manufacturing; also used in fumigants, metal cleaners, ore refining, and synthetic rubber production; [ACGIH]

Farming (Pesticides) [Category: Industry]

For cyanamide (USEPA/OPP Pesticide Code: 014002) ACTIVE products with label matches. /SRP: Registered for use in the U.S. but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

Early post-emergence control of broad-leaved weeds in alliums (onions, leeks, chives, shallots, and garlic) and bulb flowers. Also used to remove side shoots and inhibit sprouting in hops and vines.

Agrochemistry: Cyanamide is used as a plant growth regulator and budbreaking agent (Dormex) to compensate for the lack of frost and to improve the budbreak of grapes and other fruit crops in areas with mild winters. Cyanamide has a significant fungicidal and herbicidal potential and is used in pig farming to overcome sanitary problems related with the pig manure.

Cyanamide is the key raw material for many herbicides, fungicides, and insecticides. It is used to produce the herbicides Amitrol and Hexazinone and builds up the pyrimidine or 1,3,5-triazine subunit for a vast number of sulfonylurea herbicides like Bensulfuron or Metsulfuron methyl. The benzimidazole fungicides Carbendazim and Benomyl and the pyrimidine fungicides Cyprodinil, Pyrimethanil, and Mepanipyrim are based on cyanamide, as well as the pyrimidine insecticides Bupyrimate and Dimethirimol and neonicotinoids like Acetamiprid. Many fungicidal and biocidal guanidine and biguanide compounds like Dodine, Guazatine and Iminooctadine are based on cyanamide chemistry.

Dicyandiamide ... /is/ the main impurity in cyanamide.

Cyanamide, especially in solution, always contains the dimer.

2023: 260,000 lb

According to the 2006 TSCA Inventory Update Report, the 2006 Production Volume for cyanamide (CAS 420-04-2) was 1 to <10 million lbs (aggregated Import + Manufacture).

Production volumes for non-confidential chemicals reported under the Inventory Update Rule. [Table#3243]

Production volume for non-confidential chemicals reported under the 2006 Inventory Update Rule. Chemical: Cyanamide. Aggregated National Production Volume: 1 to < 10 million lbs.

Prepared commercially by continuous carbonation of calcium cyanamide in water according to the equations: 2CaNCN + 2H2O = Ca(HNCN)2 + Ca(OH)2; Ca(HNCN)2 + CO2 + H2O = 2H2NCN + CaCO3.

Cyanamide is manufactured from calcium cyanamide by continuous carbonation in an aqueous medium. In the continuous cyanamide process, the amount of calcium cyanamide and water added is equivalent to the aqueous cyanamide removed.

Cyanamide is sold as anhydrous, aqueous 50%, and calcium cyanamide. Anhydrous and aqueous 50% cyanamide contain a buffering additive, usually 2% sodium biphosphate to stabilize the pH and prevent formation of dicyanamide and urea.

Emulsifiable concentrate

Cyanamide in 50% aqueous solution: cyanamide = 50%; dicyandiamide, urea, and related compounds max. 4%; Iron max. 300 mg/L; calcium max. 100 mg/L; stabilizer max. 2%.

Cyanamide, crystalline, min 98%; dicyandiamide max. 1%; water max.

For more Formulations/Preparations (Complete) data for Cyanamide (7 total), please visit the HSDB record page.

Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing

Cyanamide: ACTIVE

CYANAMIDE IS A NAME APPLIED BOTH TO CARBODIIMIDE & TO CALCIUM DERIVATIVE, CALCIUM CYANAMIDE.