Preservatives in food: nitrates and nitrites

Nitrates and nitrites are chemicals found naturally in some foods. They may also be added to food as a preservative or to make cured meats. Learn more about where they're found and how they may affect your health.

Why preservatives are used in food

Preservatives are used to slow down the aging and spoiling of food. You may hear them referred to as chemicals that "extend the shelf life" of food.

They work by preventing or slowing down the growth of microorganisms, like mould or bacteria. Microorganisms can spoil food and make it unsafe to eat or drink. You might get food poisoning from spoiled food.

Nitrites and nitrates are used to preserve food, especially meats and cheeses. They can also be added to cured meat products to produce a pink colour.

Foods that contain nitrates and nitrites

Some foods are natural sources of nitrates and nitrites. Others have them added.

The main natural sources of nitrates and nitrites are:

  • fresh vegetables
  • fruit
  • water.

The main foods that nitrates and nitrites are added to are:

  • ham, bacon, and salami
  • some cheese and cheese products.

Are nitrates and nitrites safe?

Your chances of eating unsafe amounts of nitrates and nitrites are very low.

The effect of nitrites on some infants

Some infants have a rare condition called methaemoglobinaemia. This condition reduces the ability of their blood to transport oxygen.

How nitrates and nitrites are regulated

All food additives, including nitrates and nitrites, must be assessed for safety by Food Standards Australia New Zealand (FSANZ).

How FSANZ ensures the safety of food additives – Food Safety Australia New Zealand

Science and research on nitrates and nitrites

The acceptable daily intake (ADI) tells you how much of a specific food additive you can safely eat each day, throughout your life.

Vegetables are New Zealanders’ largest source of nitrates. Processed meats account for less than 10% of total dietary exposure to nitrites.

The average adult New Zealander eats about:

  • 14% of the ADI of nitrites
  • 18% of the ADI of nitrates.

Find about reference health standards like ADIs

Who to contact

If you have questions about nitrates and nitrites, email info@mpi.govt.nz

Last reviewed: