- Urea, also known as carbamide, is an organic compound with the chemical formula CO(NH₂)₂. It is a colorless, odorless, and highly water-soluble crystalline substance that plays a central role in the nitrogen cycle.
- In biological systems, urea is the primary nitrogen-containing end product of protein metabolism. It is synthesized in the liver through the urea cycle (also known as the ornithine cycle), where toxic ammonia—produced from the breakdown of amino acids—is converted into urea and then transported to the kidneys for excretion in urine. This process is vital for maintaining nitrogen balance and preventing the accumulation of harmful ammonia in the body.
- In industrial and commercial contexts, urea is synthesized through the reaction of ammonia and carbon dioxide under high pressure and temperature. It is one of the most widely produced chemicals globally, with diverse applications across agriculture, medicine, chemical manufacturing, and skincare. The majority of industrial urea is used as a nitrogen-rich fertilizer in agriculture due to its high nitrogen content (about 46%), making it an efficient and cost-effective means of enhancing crop yields. However, improper use can contribute to environmental problems, such as soil acidification and water pollution through nitrogen runoff and greenhouse gas emissions (e.g., nitrous oxide).
- In medicine and dermatology, urea is valued for its keratolytic and hydrating properties. It is commonly used in topical creams and ointments to treat dry, rough, or scaly skin conditions, including eczema, psoriasis, and ichthyosis. At lower concentrations (around 10%), urea acts as a moisturizer by enhancing the skin’s water-binding capacity. At higher concentrations (above 20%), it functions as a keratolytic agent, breaking down hardened skin and promoting exfoliation. These properties make it especially effective in foot creams, hand treatments, and products for calluses and thickened skin.
- Additionally, urea has various technical and industrial applications. It is used in the manufacture of resins, plastics, adhesives, and coatings—particularly urea-formaldehyde resins, which are common in particleboard and other building materials. It also serves as a raw material in the production of animal feed, deicing solutions, and certain pharmaceuticals. In automotive technology, urea solutions such as AdBlue are used in selective catalytic reduction (SCR) systems to reduce nitrogen oxide emissions from diesel engines, contributing to cleaner vehicle exhaust.
- From a biochemical perspective, the study of urea helped lay the foundation for modern organic chemistry. In 1828, German chemist Friedrich Wöhler synthesized urea from inorganic compounds (ammonium cyanate), challenging the belief that organic compounds could only be produced by living organisms. This landmark discovery marked the beginning of modern organic chemistry by demonstrating that organic molecules could be created synthetically.
