Urea is an organic chemical compound with the formula CO(NH2)2 which plays a key role in many industries and medicine. Derived from the ornithine cycle, where it is a product of ammonia conversion, it is an essential metabolite in living organisms. No wonder it is now widely used and significant in many sectors of industry and in cosmetic products.

What is urea and what are its properties?
Urea (also called carbamide) is a non-flammable, crystalline substance, usually white or colorless, with a slightly ammoniacal odor and a saltish taste. It is a hygroscopic substance, which means that it easily absorbs moisture from the environment, and also dissolves very well in water. During long-term storage in aqueous solutions, urea can decompose, producing ammonia and carbon dioxide.
Technical urea is used in many industries. It is used as a component of fertilizers and an additive to animal feed. It also serves as a raw material in the production of plastics, fireproof impregnants and adhesives.
In animal experiments, urea has shown low toxicity, both acute and chronic, and no carcinogenic effects or adverse effects on reproductive capabilities. There is no harmonized classification of urea toxicity in the European Union. This substance is characterized by very low vapor pressure, which means that exposure to it occurs mainly through inhalation of dusts. In order to protect workers from potential problems related to the presence of urea dust in the air, it has been proposed to establish a maximum allowable concentration (MAC) of 10 mg/m^3. This value is consistent with standards for other dusts that are not classified as toxic, but may pose a risk due to reduced visibility.
In addition:
- Urea is a hygroscopic solid that dissolves well in water, methanol, ethanol, glycerol, dimethyl sulfoxide (DMSO), acetic acid and concentrated hydrochloric acid.
- In aqueous solutions, it undergoes slow hydrolysis, during which ammonia and carbon dioxide are formed. The hydrolysis process can be accelerated by heating and the addition of acids or bases.
- Urea is characterized by very poor solubility in benzene and chloroform, and it dissolves poorly in ethyl ether.
- Urea can react with some substances, forming products with strong explosive properties (e.g. in the case of reactions with sodium or calcium chlorates(I)).
The process of urea production — from raw material to final product
#1. Ammonia synthesis
Urea production begins with ammonia synthesis, mainly in the Haber-Bosch process. This process involves the reaction of nitrogen (N2) with hydrogen (H2), which are mainly sourced from natural gas. High pressure and temperature (approx. 450°C and 200 atm) and the presence of an iron-based catalyst enable this exothermic reaction to take place.
#2. Urea synthesis
The next stage is the reaction of ammonia with carbon dioxide (CO2) to produce urea. This process takes place in two main stages. The first is the formation of ammonium carbamate, and the second is the decomposition of ammonium carbamate. Ammonium carbamate is then converted into urea and water under high pressure (150-250 atm) and temperature (180-190°C).
#3. Condensation and crystallization
The resulting urea solution is then concentrated by evaporating water in a vacuum evaporator. This process results in urea in the form of a concentrated solution.
#4. Granule formation
The concentrated urea solution is cooled and then granulated in special drum or plate granulators, where, under the influence of movement and additional cooling, urea crystallizes, forming granules.
The urea granules are then dried in drum dryers to remove excess moisture and then cooled in coolers. This process ensures the stability of the granules and optimizes their physical properties.
#5. Packaging and storage
Finally, the finished urea is packed into bags or transported directly to storage tanks, from where it is distributed to end customers.
The importance of urea in industrial sectors
In the selective catalytic reduction (SCR), urea helps to reduce nitrogen oxide emissions from stationary and mobile sources. In the pharmaceutical and cosmetic industries and in household chemicals, urea is valued as a component of many preparations. It is also used for de-icing roads, railway tracks and runways, and in the food industry it is added to bakery products, alcoholic beverages and gelatine products.
Urea in agriculture
Thanks to its high nitrogen content (around 46%), urea is used in fertilization programs, supporting intensive plant growth. Currently, it is used in the form of granules or solutions, where it quickly hydrolyzes to ammonia and carbon dioxide, releasing nitrogen available for plants. However, what is important – due to the high volatility of ammonia, it is necessary to quickly incorporate urea into the soil after application to minimize nitrogen losses.
Find out more: https://www.products.pcc.eu/en/blog/what-are-organic-fertilisers-and-what-should-we-know-about-them/
Urea in cosmetics
Urea is one of the most effective moisturizing ingredients used in the cosmetic industry. It is a component of the natural moisturizing factor (NMF) found in keratinocytes, which is crucial for maintaining the appropriate level of hydration of the stratum corneum of the epidermis (the so-called humectant). The effectiveness of urea in cosmetics depends on its concentration: in low doses it acts mainly as a moisturizer, while in higher concentrations it has keratolytic properties. Interestingly, its derivatives are also used, such as allantoin which promotes the regeneration of the epidermis.[2]
Find out more : https://www.products.pcc.eu/en/blog/cosmetic-ingredients/ and on https://www.products.pcc.eu/en/inci-names/
Urea in the pharmaceutical industry
In pharmacy, urea is used as an osmotic agent in diuretics and as an ingredient of creams and ointments for treating dermatological conditions, such as psoriasis, eczema. Learn more at:
https://www.products.pcc.eu/en/k/pharmaceutical-industry/
Urea in the textile industry
Interestingly, urea is also used as a dye additive. Thanks to its chemical properties, it improves the solubility and stability of dyes, which is crucial in the production of highly intensive colors. Urea is also used in the production of certain types of artificial fabrics and as a softening component.
Urea in the chemical industry
Urea plays the role of a raw material in the production of many chemical products, including the production of urea-formaldehyde resins, which are widely used as adhesives in the wood and furniture industry. These resins they are characterized by exceptional durability and resistance to moisture, thanks to which they are used in production chipboard and plywood.
The impact of urea on the environment – challenges and solutions
Challenge #1: Eutrophication of surface waters
Excessive use of urea in agriculture can lead to the leaching of excess nitrogen into rivers and lakes. This, in turn, can cause eutrophication, i.e. excessive growth of algae and other aquatic plants, which disrupts the balance of ecosystems and reduces the oxygen level in the water.
In the face of this challenge, it is crucial to introduce nutrient management practices, i.e. the use of GPS technology to control optimal doses.
Challenge #2: Emissions of greenhouse gases
The hydrolysis of urea in the soil leads to the production of ammonia, which can be converted into nitrogen oxides (NOx) – potent greenhouse gases. NOx emissions contribute to global warming and air quality problems, which is why it is necessary to implement technologies to reduce ammonia and NOx emissions in agriculture, such as optimizing soil pH and using urease inhibitors which slow down the decomposition of urea.
- SKOWROŃ, J. Mocznik–frakcja wdychalna.
- Kapuścińska, A., & Nowak, I. (2014). Wykorzystanie mocznika i jego pochodnych w przemyśle kosmetycznym. Chemik, 68(2), 91-96.