What Are Nitrosamines and Where Are they Found?

Found in everything from water and food to medications, nitrosamines are organic compounds with a unique chemical structure. In low concentrations nitrosamines are considered safe. However high levels and ongoing exposure can create complications. The US Food & Drug Administration (FDA) warns that some nitrosamines can increase the risk of cancer.

Read on as we take a closer look at nitrosamines and answer questions like how they’re formed and where they’re found. We’ll also cover the difference between nitrates, nitrites and nitrosamines.

Nitrates vs nitrites

Before we get started, let’s take a moment to define nitrates (NO3) and nitrites (NO2). Both are organic compounds, though with some key differences. Nitrates are made up of a single nitrogen atom and three oxygen atoms. Nitrites also have a single nitrogen atom and just two oxygen atoms. While nitrates are considered stable and harmless, bacteria and enzymes can convert them into nitrites. These can then form carcinogenic nitrosamines.

Now we know more about nitrates and nitrites, let’s move onto where nitrosamines are found.

Nitrosamines in food

Nitrosamines are common in highly processed foods such as cured meat and alcoholic beverages. The unintentional byproducts form when nitrates react with organic compounds called amines. Widely used in the food and beverage sector, nitrates are natural chemicals that prevent the growth of bacteria. They’re also used to enhance flavour and colour. While useful as a food additive, nitrates can transform into nitrites, which form harmful nitrosamines. Foods containing nitrosamine precursors can also form nitrosamines in the mouth and stomach. This occurs when nitrates (either naturally occurring or artificial) react with acidic pH in the body.

Nitrosamines in pharmaceuticals

Nitrosamines can form during chemical reactions that take place during drug manufacturing processes. They can contaminate a wide range of medications used to treat everything from heartburn and blood pressure to diabetes and acid reflux. In the US, the FDA recently recalled all ranitidine, a medication uses to treat conditions like gastroesophageal reflux disease and peptic ulcer disease.

Nitrosamines in cosmetics

From contaminated raw materials to chemical reactions during the manufacturing process, nitrosamines can appear in cosmetics for all kinds of reasons. Campaign groups recommend avoiding products featuring wetting agents like diethanolamine (DEA) and triethanolamine (TEA), which can trigger the formation of nitrosamines.

Nitrosamines in water

In the Encyclopedia of Toxicology (Third Edition), author H. Robles spotlights the discovery of nitrosamines in drinking water. The organic compounds are linked to the use of a disinfectant called dichloramine. Nitrates are also used excessively in fertilisers, which are often washed into drinking water reservoirs and underground tables.

Nitrosamines aren’t the only concern for drinking water. Volatile organic compounds (VOCs) are also a serious issue. Find out more about the latest techniques being used to monitor VOC concentrations in ‘Volatile organic compounds analysis in drinking water with Headspace GC/MSD using hydrogen carrier gas and hydroInert source’.