Common applications include
- More than 90% of world industrial production of urea is destined for use as a nitrogen-release fertilizer.[9] Urea has the highest nitrogen content of all solid nitrogenous fertilizers in common use. Therefore, it has a low transportation cost per unit of nitrogen nutrient. The most common impurity of synthetic urea is biuret, which impairs plant growth. Urea breaks down in the soil to give ammonium ions (NH+4). The ammonium is taken up by the plant through its roots. In some soils, the ammonium is oxidized by bacteria to give nitrate (NO−3), which is also a nitrogen-rich plant nutrient. The loss of nitrogenous compounds to the atmosphere and runoff is wasteful and environmentally damaging so urea is sometimes modified to enhance the efficiency of its agricultural use. Techniques to make controlled-release fertilizers that slow the release of nitrogen include the encapsulation of urea in an inert sealant, and conversion of urea into derivatives such as urea-formaldehyde compounds, which degrade into ammonia at a pace matching plants' nutritional requirements.
Resins
Urea is a raw material for the manufacture of urea-formaldehyde resins, used mainly in wood-based panels such as particleboard, fiberboard and plywood.
Automobile systems
Urea is used in Selective Non-Catalytic Reduction (SNCR) and Selective Catalytic Reduction (SCR) reactions to reduce the NOx pollutants in exhaust gases from combustion from diesel, dual fuel, and lean-burn natural gas engines
Miscellaneous uses
An ingredient in diesel exhaust fluid (DEF), which is 32.5% urea and 67.5% de-ionized water. DEF is sprayed into the exhaust stream of diesel vehicles to break down dangerous NOx emissions into harmless nitrogen and water.
A component of animal feed, providing a relatively cheap source of nitrogen to promote growth
A non-corroding alternative to rock salt for road de-icing.[31] It is often the main ingredient of pet friendly salt substitutes although it is less effective than traditional rock salt or calcium chloride.
A main ingredient in hair removers such as Nair and Veet
A browning agent in factory-produced pretzels
An ingredient in some skin cream, moisturizers, hair conditioners, and shampoos
A cloud seeding agent, along with other salts
A flame-proofing agent, commonly used in dry chemical fire extinguisher charges such as the urea-potassium bicarbonate mixture
An ingredient in many tooth whitening products
An ingredient in dish soap
Along with diammonium phosphate, as a yeast nutrient, for fermentation of sugars into ethanol
A nutrient used by plankton in ocean nourishment experiments for geoengineering purposes
As an additive to extend the working temperature and open time of hide glue
As a solubility-enhancing and moisture-retaining additive to dye baths for textile dyeing or printing
As an optical parametric oscillator in nonlinear optics
