What’s the latest on nitrosamines?

What are nitrosamines?

Nitrosamines are a group of compounds created by chemical reactions involving nitrites reacting with a secondary or tertiary amine. Nitrites can be formed from nitrates. High temperatures and high acidity promote their formation. High temperatures can occur while frying food. Stomach acid results in high acidity.

Where are nitrosamines found?

Nitrosamines are found in food, tobacco, cosmetics, some medications, some toys and games (such as those made of rubber), condoms, and contaminated drinking water. They are present in many of the foods we eat every day, including green leafy vegetables, processed meats (such as bacon, ham, and sausage), processed fish, and some cheeses.

The nitrosamine content of food varies with respect to food temperature, moisture, and cooking methods. For example, raw bacon contains minimal nitrosamines, whereas higher levels are found in crispy fried fatty bacon. Alcoholic beverages such as beer may contain nitrosamines. Because they are found in tobacco smoke, motor vehicle emissions, cooking and industrial processes, nitrosamines are also present in the air.

A chemical reaction between nitrites (which are converted from nitrates in water and food) with amines (which are found in some foods and drugs) can lead to formation of nitrosamines in the body’s digestive tract.

Are nitrosamines linked to cancer?

There are many different nitrosamines, and some are carcinogens. Nitrosamines are grouped into 4 categories according to their carcinogenic potential. Group 1 (NNN and NNK) are carcinogenic to humans, Group 2A (NDMA, NDEA, NIPEA, NMBA, NDIPA, NMPA) are probably carcinogenic, Group 2B are possibly carcinogenic, and Group 3 are considered not carcinogenic to humans.

In the body, nitrosamines are converted into reactive chemicals that damage DNA, which leads to mutations. They also cause formation of reactive oxygen species, which damage DNA, lipids, and proteins. Depending on the nitrosamine, cancer of the brain, esophagus, stomach, nose, liver, kidneys, and/or lungs may occur.

Exposure to low levels of nitrosamines, such as those found in many foods as well as drinking water, is likely not dangerous and will not cause an increased risk of cancer. However, exposure to higher levels of nitrosamines, especially over long periods of time, may increase one’s risk of developing certain types of cancer.

Drug recalls due to nitrosamine contamination

In July 2018, the FDA issued a recall for the prescription medication valsartan after finding that certain brands of this medication contained high amounts of NDMA, which is considered a probable carcinogen. In medications, NDMA can be unintentionally introduced as a contaminant through the addition of solvents during the manufacturing process, or can be formed as a byproduct of the active ingredients.

In September 2021, a recall was issued for the smoking cessation drug Chantix® (varenicline) due to contamination with nitrosamines. Examples of other drug recalls due to higher nitrosamine include irbesartan, losartan, metformin, ranitidine, and nizatidine.

More recent recalls include quinapril and orphenadrine in 2022 and prazosin in 2025.

What are nitrosamine limits in medication?

In 2020, the FDA established limits for nitrosamines in medications. The FDA considers nitrosamine impurities at levels of 26.5 ng/day to be acceptable. The FDA limits were designed to minimize cancer risk and assumed that a person might take a nitrosamine-contaminated medication daily for 70 years. These levels are well below the limits set by the World Health Organization for nitrosamines in drinking water. Nitrosamine in medications is just one potential exposure source, and it’s unlikely that use of nitrosamine-contaminated medications will significantly increase a person’s risk of cancer.

Where do things stand with nitrosamine today?

Drugs: The FDA has issued monitoring and testing guidelines for over 250 nitrosamines in medications that took effect in August 2025. If manufacturers don’t comply or do not detect impurities in a drug formulation, then the FDA will issue a class 2 recall which requires immediate removal of the drugs from shelves.

Environment: The EPA has classified several nitrosamines as probable carcinogens and has established health advisory levels for NDMA in drinking water. These are not enforceable.

Work: NDMA and other nitrosamines are regulated by the Occupational Safety and Health Administration (OSHA). OSHA requires that workers be exposed to the lowest possible levels of those nitrosamines that it considers potential occupational carcinogens. 

Have questions about contaminated food or medicine?

If you have questions about contaminated food or medication or want information on recalls, use the webPOISONCONTROL^® online tool to get help, or call your poison center at 1-800-222-1222. Whether online or by phone, expert guidance is always free, confidential, and available 24 hours a day.