Urea Overview

Urea,(NH₂)₂CO, is a colorless organic chemical compound compound also known by the International Nonproprietary Name (rINN) carbamide, as established by the World Health Organization. It is highly soluble in water and has a pKa close to zero. Urea is essentially the waste produced when the body metabolizes protein. It is not only produced by humans, but also by many other mammals, as well as amphibians and some fish. Urea was the first natural compound to be artificially synthesized using inorganic compounds — a scientific breakthrough.

The primary raw material used to manufacture Urea is natural gas, which ties the costs directly to gas prices. Consequently, new plants are only being built in areas with large natural gas reserves where prices are lower. Finished product is transported around the globe in large shipments of 30,000 metric tons. The market price for Urea is directly related to the world price of natural gas and the demand for agricultural products. Prices can be very volatile, and at times, unpredictable. TCC is positioned to know the world markets and keep your prices competitive.

Urea is a raw material used in the manufacture of many chemicals, such as various plastics, Urea-formaldehyde resins and adhesives. It is also essential for making feedstock, glue, fertilizer, commercial products, and in resin production. It is widely used in many developing parts of the world and is popular on international trading markets due to its cheap production and transportation costs.

Over 90 percent of the world's production of the substance is used for fertilizer-related products. When used in this way, it usually takes the form of granules, prills, or crystals. Farmers manually distribute the substance or it is scattered in the appropriate form with the aid of farming equipment. Urea is considered an effective feed, since it contains nitrogen, which can aid animal growth. The relatively cheap price of products made with the substance also makes feed a popular choice by many farmers.

About Urea

History
French chemist Hillaire Rouelle discovered Urea in 1773. In 1828, just 55 years after its discovery, Urea became the first organic compound to be synthetically formulated, this time by a German chemist named Friedrich Wöhler, one of the pioneers of organic chemistry. Wöhler obtained Urea by treating silver isocyanate with ammonium chloride in a failed attempt to prepare ammonium cyanate.

Synthetic Urea is created from synthetic ammonia and carbon dioxide and can be produced as a liquid or a solid. The process of dehydrating ammonium carbamate under conditions of high heat and pressure to produce Urea was first implemented in 1870 and is still in use today. Uses of synthetic Urea are numerous and therefore production is high. Approximately one million pounds of Urea is manufactured in the United States alone each year, most of it used in fertilizers. Nitrogen in Urea makes it water soluble, a highly desired property in this application.

Urea was found to be useful for commercial and industrial applications in the production of some types of plastics, animal feed, glues, toilet bowl cleaners, dish washing machine detergents, hair coloring products, pesticides, and fungicides. Medicinally, it is incorporated in the manufacture of barbiturates, dermatological products that re-hydrate the skin, and diuretics.

Urea is naturally produced when the liver breaks down protein or amino acids, and ammonia. The kidneys then transfer the Urea from the blood to the urine. Extra nitrogen is expelled from the body through Urea, and because it is extremely soluble, it is a very efficient process. The average person excretes about 30 grams of Urea a day, mostly through urine, but a small amount is also secreted in perspiration.

Physicians found that Urea levels can be used to detect diseases and disorders that affect the kidneys, such as acute kidney failure or end-stage renal disease (ESRD). The blood Urea nitrogen (BUN) and the urine Urea nitrogen (UUN) tests, which measure Urea nitrogen levels in the blood and urine, are often used to assess how well a patient's kidneys are functioning. Increased or decreased Urea levels, however, do not always indicate kidney problems, but instead may reflect dehydration or increased protein intake.

Physiology
Urea is synthesized in the body of many organisms as part of the Urea cycle, either from the oxidation of amino acids or from ammonia. In this cycle, amino groups donated by ammonia and L-aspartate are converted to Urea, while L-ornithine, citrulline, L-argininosuccinate, and L-arginine act as intermediates. Urea production occurs in the liver and is regulated by N-acetylglutamate. Urea is found dissolved in blood (in the reference range of 2.5 to 7.5 mmol/liter) and is excreted by the kidney as a component of urine. In addition, a small amount of Urea is excreted (along with sodium chloride and water) in sweat.

Aminoacids from ingested food which are not used for the synthesis of proteins and other biological substances are oxidized by the body as an alternative source of energy and yielding Urea and carbon dioxide. The oxidation pathway starts with the removal of the amino group by a transaminase, the amino group is then fed into the Urea cycle.

Ammonia (NH3) is another common byproduct of the metabolism of nitrogenous compounds. Ammonia molecules are smaller, more volatile and more mobile than Urea's. If allowed to accumulate, ammonia would raise the pH in cells to toxic levels. Therefore many organisms convert ammonia to Urea, even though this synthesis has a net energy cost. Being practically neutral and highly soluble in water, Urea is a safe vehicle for the body to transport and excrete excess nitrogen.

Applications using Urea

Agriculture
More than 90 percent of world Urea production is destined for use as a nitrogen-release fertilizer. Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use (46.7%). Therefore, it has the lowest transportation costs per unit of nitrogen nutrient.

In the soil, it hydrolyses back to ammonia and carbon dioxide. The ammonia is oxidized by bacteria in the soil to nitrate, which can be absorbed by the plants. Urea is also used in many multi-component solid fertilizer formulations. Urea is highly soluble in water, therefore, very suitable for use in fertilizer solutions (in combination with ammonium nitrate: UAN), e.g., in 'foliar feed' fertilizers. For fertilizer use, granules are preferred because of their narrower particle size distribution, an advantage for mechanical application.

The most common impurity of synthetic Urea, biuret, must be present at less than 2 percent of the time, as it impairs plant growth.

Urea is spread at rates between 40 and 300 kg/ha, but actual spreading rates will vary according to farm type and region. It is better to make several small to medium applications at intervals to minimize leaching losses and increase efficient use of the Nitrogen applied, compared with single heavy applications. During summer, Urea should be spread just before, or during rain to reduce possible losses from volatilization (process wherein nitrogen is lost to the atmosphere as ammonia gas). Urea should not be mixed with other fertilizers, as problems of physical quality may result.

Because of the high nitrogen concentration in Urea, achieving an even spread is important. The application equipment must be calibrated correctly and used properly. Drilling must not occur on contact with or close to seeding due to the risk of germination damage. Urea dissolves in water to be applied as a spray or through irrigation systems.

In grain and cotton crops, Urea is often applied at the time of the last cultivation before planting. In high rainfall areas and on sandy soils (where nitrogen can be lost through leaching) and where good in-season rainfall is expected, Urea can be side or top-dressed during the growing season. Top-dressing is also popular on pasture and forage crops. In cultivating sugarcane, Urea is side-dressed after planting, and applied to each ratoon crop.

For irrigated crops, Urea can be applied dry to the soil, or dissolved and applied through the irrigation water. Urea will dissolve in its own weight in water, but it becomes increasingly difficult to dissolve as the concentration increases. Dissolving Urea in water is endothermic, causing the temperature of the solution to fall when Urea dissolves.

When preparing Urea solutions for fertigation (injection into irrigation lines), dissolve no more than 30 kg of Urea per 100 L of water.

In foliar sprays, 0.5 to 2.0 percent concentrations of Urea are often used for horticultural crops. As Urea sprays may damage crop foliage, advice for specific amounts should be sought before use. Low-biuret grades of Urea should also be used if Urea sprays are to be applied regularly or to sensitive horticultural crops.

Like most nitrogen products, Urea absorbs moisture from the atmosphere. Therefore it should be stored either in closed/sealed bags on pallets, or, if stored in bulk, under cover with a tarpaulin. As with most solid fertilizers, it should also be stored in a cool, dry, well-ventilated area.

Chemical industry
Urea is a raw material used in the manufacture of many important chemicals, such as:

1. Various plastics, especially the Urea-formaldehyde resins
2. Various adhesives, such as Urea-formaldehyde or the Urea-melamine-formaldehyde used in marine plywood
3. Potassium cyanate, another industrial feedstock
4. Urea nitrate, an explosive

Urea has the ability to trap many organic compounds in the form of clathrates. The organic compounds are held in channels formed by interpenetrating helices comprising of hydrogen-bonded Urea molecules. This behavior can be used to separate mixtures, and has been used in the production of aviation fuel and lubricating oils, and in the separation of paraffin.

As the helices are interconnected, all helices in a crystal must have the same molecular handedness. This is determined when the crystal is nucleated and can thus be forced by seeding. The resulting crystals have been used to separate racemic mixtures.

Automobile systems
Urea is used in SNCR and SCR reactions to reduce the NOx pollutants in exhaust gases from combustion, for example, from power plants and diesel engines. The BlueTec system, for example, injects water-based Urea solution into the exhaust system. The ammonia produced by decomposition of the Urea reacts with the nitrogen oxide emissions and is converted into nitrogen and water within the catalytic converter.

Other commercial uses

1. A stabilizer in nitrocellulose explosive
2. A component of animal feed, providing a relatively cheap source of nitrogen to promote growth
3. A non-corroding alternative to rock salt for road de-icing, and the resurfacing of snowboarding half pipes and terrain parks
4. A flavor-enhancing additive for cigarettes
5. A main ingredient in hair removers such as Nair or Veet
6. A browning agent in factory-produced pretzels
7. An ingredient in some hair conditioners, facial cleansers, bath oils, skin softeners, and lotions
8. A reactant in some ready-to-use cold compresses for first-aid use, due to the endothermic reaction itcreates when mixed with water
9. A cloud seeding agent, along with other salts
10. A flame-proofing agent, commonly used in dry chemical fire extinguisher charges such as the Urea-potassium bicarbonate mixture.
11. An ingredient in many tooth whitening products
12. An ingredient in dish soap
13. Along with ammonium phosphate, as a yeast nutrient, for fermentation of sugars into ethanol
14. A nutrient used by plankton in ocean nourishment experiments for geoengineering purposes
15. As an additive to extend the working temperature and open time of hide glue
16. As a solubility-enhancing and moisture-retaining additive to dye baths for textile dyeing or printing

Laboratory uses
Urea in concentrations up to 10 M is a powerful protein denaturant as it disrupts the noncovalent bonds in the proteins. This property can be exploited to increase the solubility of some proteins. A mixture of Urea and choline chloride is used as a deep eutectic solvent, a type of ionic liquid.

Urea can serve as a hydrogen source, for subsequent power generation in a fuel cell. Urea present in urine/wastewater can be used directly (though bacteria normally quickly degrade Urea.) Producing hydrogen by electrolysis of Urea solution occurs at a lower voltage and uses less energy than by electrolysis of water.

Medical use
Urea is used in topical dermatological products to promote rehydration of the skin. If covered by an occlusive dressing, 40 percent Urea preparations may also be used for non-surgical debridement of nails. This drug is also used as an earwax removal aid.

Like saline, Urea injection is used to perform abortions. It is also the main component of an alternative medicinal treatment referred to as urine therapy.

The blood Urea nitrogen (BUN) test is a measure of the amount of nitrogen in the blood that comes from Urea. It is used as a marker of renal function.

Urea labeled with carbon-14 or carbon-13 is used in the Urea breath test, which is used to detect the presence of the bacteria Helicobacter pylori (H. pylori) in the stomach and duodenum of humans, associated with ulcers. The test detects the characteristic enzyme Urease, produced by H. pylori, by a reaction that produces ammonia from Urea. This increases the pH (reduces acidity) of the stomach environment around the bacteria. Similar bacteria species to H. pylori can be identified by the same test in animals such as apes, dogs, and cats (including big cats).

De-Icer
Urea is a safe, non-corrosive fertilizer alternative for de-icing. The chemical is easy to use on runways and walkways as well as on landing gears and other vital parts located on the under-carriage of aircraft that must always be protected from corrosion. Airports in many areas that can't use highly corrosive chloride salts for de-icing operations use Urea as the preferred alternative.

Product Specification - Urea

Material Safety Data Sheet

Section 1: Chemical Product and Company Identification
Product Name: Urea
CAS#: 57-13-6
RTECS: YR6250000
Synonym: Carbamide
Chemical Name: carbonyldiamide
Chemical Formula: (NH2)2CO or CH4N2O

Contact Information:

• The Chemical Company
• 19 Narragansett Avenue
• PO Box 436
• Jamestown RI 02835
•  
• CHEMTREC (24HR Emergency Telephone), call: 1-800-424-9300
• International CHEMTREC, call: 1-703-527-3887

Section 2: Composition and Information on Ingredients
Composition:

Toxicological Data on Ingredients: Urea: ORAL (LD50): Acute: 8471 mg/kg [Rat]. 11000 mg/kg [Mouse].

Section 3: Hazards Identification
Potential Acute Health Effects: Hazardous in case of skin contact (irritant), of eye contact (irritant), of ingestion, of inhalation.

Potential Chronic Health Effects:
CARCINOGENIC EFFECTS: Not available.
MUTAGENIC EFFECTS: Mutagenic for mammalian somatic cells.
TERATOGENIC EFFECTS: Not available.
DEVELOPMENTAL TOXICITY: Not available.
The substance may be toxic to blood, cardiovascular system.
Repeated or prolonged exposure to the substance can produce target organs damage.

Section 4: First Aid Measures

Eye Contact:
Check for and remove any contact lenses. In case of contact, immediately flush eyes with plenty of water for at least 15 minutes. Cold water may be used. Get medical attention.
Skin Contact:
In case of contact, immediately flush skin with plenty of water. Cover the irritated skin with an emollient. Remove contaminated clothing and shoes. Cold water may be used.Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention.
Serious Skin Contact:
Wash with a disinfectant soap and cover the contaminated skin with an anti-bacterial cream. Seek medical attention.
Inhalation: If inhaled, remove to fresh air. If not breathing, give artificial respiration. If breathing is difficult, give oxygen. Get medical attention.
Serious Inhalation: Not available.
Ingestion:
Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. Loosen tight clothing such as a collar, tie, belt or waistband. Get medical attention if symptoms appear.
Serious Ingestion: Not available.

Section 5: Fire and Explosion Data

Flammability of the Product: May be combustible at high temperature.
Auto-Ignition Temperature: Not available.
Flash Points: Not available.
Flammable Limits: Not available.
Products of Combustion: These products are carbon oxides (CO, CO2), nitrogen oxides (NO, NO2...).
Fire Hazards in Presence of Various Substances: Slightly flammable to flammable in presence of heat.
Explosion Hazards in Presence of Various Substances:
Risks of explosion of the product in presence of mechanical impact: Not available.
Risks of explosion of the product in presence of static discharge: Not available.
Fire Fighting Media and Instructions:
SMALL FIRE: Use DRY chemical powder.
LARGE FIRE: Use water spray, fog or foam. Do not use water jet.
Special Remarks on Fire Hazards: Not available.
Special Remarks on Explosion Hazards: Not available.

Section 6: Accidental Release Measures
Small Spill:
Use appropriate tools to put the spilled solid in a convenient waste disposal container. Finish cleaning by spreading water on the contaminated surface and dispose of according to local and regional authority requirements.
Large Spill:
Use a shovel to put the material into a convenient waste disposal container. Finish cleaning by spreading water on the contaminated surface and allow to evacuate through the sanitary system.
 
Section 7: Handling and Storage
Precautions:
Keep locked up.. Keep away from heat. Keep away from sources of ignition. Empty containers pose a fire risk, evaporate the residue under a fume hood. Ground all equipment containing material. Do not ingest. Do not breathe dust. Wear suitable protective clothing. In case of insufficient ventilation, wear suitable respiratory equipment. If ingested, seek medical advice immediately and show the container or the label. Avoid contact with skin and eyes. Keep away from incompatibles such as oxidizing agents.
Storage: Keep container tightly closed. Keep container in a cool, well-ventilated area. Do not store above 23°C (73.4°F).
 
Section 8: Exposure Controls/Personal Protection
Engineering Controls:
Use process enclosures, local exhaust ventilation, or other engineering controls to keep airborne levels below recommended exposure limits. If user operations generate dust, fume or mist, use ventilation to keep exposure to airborne contaminants below the exposure limit.
Personal Protection:
Splash goggles. Lab coat. Dust respirator. Be sure to use an approved/certified respirator or equivalent. Gloves.
Personal Protection in Case of a Large Spill:
Splash goggles. Full suit. Dust respirator. Boots. Gloves. A self contained breathing apparatus should be used to avoid inhalation of the product. Suggested protective clothing might not be sufficient; consult a specialist BEFORE handling this product.
Exposure Limits: Not available.
 
Section 9: Physical and Chemical Properties
Physical state and appearance: Solid prills
Odor:
Almost odorless; May gradually develop slight odor of ammonia, especially in presence of moisture.
Taste: Cooling. Saline
Molecular Weight: 60.06 g/mole
Color: White.
pH (1% soln/water): Not available.
Boiling Point: Not available.
Melting Point: 132.7°C (270.9°F)
Critical Temperature: Not available.
Specific Gravity: 1.323 (Water = 1)
Vapor Pressure: Not applicable.
Vapor Density: 2.07 (Air = 1)
Volatility: Not available.
Odor Threshold: Not available.
Water/Oil Dist. Coeff.: The product is more soluble in water; log(oil/water) = -2.1
Ionicity (in Water): Not available.
Dispersion Properties: See solubility in water.
Solubility: Easily soluble in cold water, hot water.
 
Section 10: Stability and Reactivity Data
Stability: The product is stable.
Instability Temperature: Not available.
Conditions of Instability: Excess heat, excess dust generation, incompatible materials. Incompatibility with various substances: Reactive with oxidizing agents.
Corrosivity: Not available.
Special Remarks on Reactivity:
Hygroscopic. Aborbs moisture from air. Reacts violently with Gallum Perchlorate. Reacts with chlorine to form chloramines. It also reacts with the following: sodium hypochlorite, sodium nitrate, calcium hypochlorite, NaNO2, P2Cl5, nitrosyl perchlorate, strong oxidizing agents (permanganate, nitrate, dichromate, chloride)
Special Remarks on Corrosivity: Not available.
Polymerization: Will not occur.
 
Section 11: Toxicological Information
Routes of Entry: Inhalation. Ingestion.
Toxicity to Animals: Acute oral toxicity (LD50): 8471 mg/kg [Rat].
Chronic Effects on Humans:
MUTAGENIC EFFECTS: Mutagenic for mammalian somatic cells. May cause damage to the following organs: blood, cardiovascular system. Other Toxic Effects on Humans: Hazardous in case of skin contact (irritant), of ingestion, of inhalation.
Special Remarks on Toxicity to Animals: Not available.
Special Remarks on Chronic Effects on Humans:
May cause adverse reproductive effects (fetotoxicity) and genetic material (mutagenicity) based on animal studies.  Passes through the placental barrier in human and is present in breast milk.
Special Remarks on other Toxic Effects on Humans:
Acute Potential Health Effects:
Skin: Causes skin irritation.
Eyes: Causes eye irritation.
Inhalation: Causes irritation of the respiratory tract, nose, and throat, coughing and sneezing. May also affect blood, metabolsim and urinary system. Ingestion: Causes digestive (gastrointestinal) tract irritation with nausea, vomiting, and diarrhea. May affect behavior (altered sleep time, change in motor activity), cardiovascular system (heart rate), and the brain. May also affect the blood and may cause tumorigenic effects.
Chronic Potential Health Effects: Prolonged exposure may cause adverse reproductive effects. Laboratory experiments on animals have resulted in mutagenic effects. Prolonged exposure or exposure at high concentrations may cause eye damage.

Section 12: Ecological Information
Ecotoxicity: Not available.
BOD5 and COD: Not available.
Products of Biodegradation:
Possibly hazardous short term degradation products are not likely. However, long term degradation products may arise.
Toxicity of the Products of Biodegradation: The product itself and its products of degradation are not toxic.
Special Remarks on the Products of Biodegradation: Not available.
 
Section 13: Disposal Considerations
Waste Disposal:
Waste must be disposed of in accordance with federal, state and local environmental control regulations.
 
Section 14: Transport Information
DOT Classification: Not a DOT controlled material (United States).
Identification: Not applicable.
Special Provisions for Transport: Not applicable.
 
Section 15: Other Regulatory Information
Federal and State Regulations:
Minnesota: Urea
TSCA 8(b) inventory: Urea
Other Regulations:
OSHA: Hazardous by definition of Hazard Communication Standard (29 CFR 1910.1200).
EINECS: This product is on the European Inventory of Existing Commercial Chemical Substances.
Other Classifications:
WHMIS (Canada): Not controlled under WHMIS (Canada).
DSCL (EEC):
R36/38- Irritating to eyes and skin.
R40- Possible risks of irreversible effects.
S24/25- Avoid contact with skin and eyes.
HMIS (U.S.A.):
Health Hazard: 2
Fire Hazard: 1
p. 5
Reactivity: 0
Personal Protection: E
National Fire Protection Association (U.S.A.):
Health: 2
Flammability: 1
Reactivity: 0
Specific hazard:
Protective Equipment:
Gloves.
Lab coat.
Dust respirator. Be sure to use an approved/certified respirator or equivalent.
Splash goggles.
 
Section 16: Other Information
References: Not available.
Other Special Considerations: Not available.
Created: 10/10/2005 08:32 PM
Last Updated: 10/10/2005 08:32 PM 

Shipping & Ordering Information

Urea is available for shipping throughout the continental United States with a one week lead time for delivery. Please call (401) 423-3100 for details. Prilled Urea can be delivered in 25 Kg. Bags, 1,000 Kg. or 2,000 lb. Supersacks, Bulk Trucks and Bulk Railcars. It is also available in solution in varying concentrations.

Contact

The Chemical Company
19 Narragansett Ave.
Post Office Box 436
Jamestown, RI 02835-0436

Telephone: (401) 423-3100
FAX: (401) 423-3102

Robert N. Roach III "Robb"
President
Cell: (401) 864-3111
Email: robb@thechemco.com