Nitrosation is a chemical reaction that involves the introduction of a nitroso group (–NO) into a molecule. This process typically occurs when amines react with nitrous acid or nitrites, leading to the formation of nitrosamines, which are compounds that can have significant biological effects. Nitrosation is important in various fields, including organic chemistry and toxicology. In biological systems, nitrosation can occur in the stomach, where dietary nitrates and nitrites are converted into nitrosamines. Some nitrosamines are known to be carcinogenic, meaning they can potentially lead to cancer. Understanding nitrosation is crucial for assessing the risks associated with certain foods and environmental exposures, particularly in relation to cancer research.