Label: Foods containing more N- nitroso compounds include salted fish, sausages, bacon, ham, fish sauce and shrimp paste. In addition, beer also contains N- nitroso compounds, although the content is not too high, but due to the large amount of drinking, attention should also be paid. To prevent the possible harm of N- nitroso compounds to people, we should start from the following aspects. 1. Foods that are not eaten immediately should be refrigerated to ensure the freshness of the food, and to prevent fish, meat, shells and other foods with high protein content from deteriorating and producing secondary amine compounds. 2, reasonable consumption of pickles pickles should generally be eaten after a week of pickling, because the nitrite content has dropped significantly. 3. Always eat a certain amount of fresh vegetables, fruits and other foods with high vitamin C and carotene content to prevent precursors from synthesizing N- nitroso compounds in the stomach. 4. Don't drink a lot of beer for a long time. 5. Pay attention to oral hygiene and brush your teeth after meals to prevent food residues from being synthesized into N- nitroso compounds by bacteria. If we can do the above, we can effectively prevent the harm of N- nitroso compounds to human beings.