Dioxins are chemicals produced both naturally and by some human activities, like manufacturing. Food crops and animals may be exposed to these dioxins in the environment. Learn more about dioxins, how they may affect your health, and how their use is monitored.

What are dioxins?

Dioxins are a family of colourless, odourless, organic compounds that are produced from:

  • volcanoes and forest fires
  • man-made processes such as manufacturing, incineration, and paper and pulp bleaching
  • exhaust emissions
  • burning municipal waste, household trash and fuels like coal, wood or oil.

Dioxins in food

Dioxins get into the food supply in several ways. Plants and animals are exposed to dioxins through particles in the air, and fish are exposed mainly from dioxins in contaminated particles or debris in water.

Dioxin particles that settle on fruit and vegetables can be removed by washing, but dioxins can accumulate in animals' fatty tissues, which we then eat.

How can dioxins affect health?

Dioxins' long-term effects on health are uncertain. Because they're bound up in body fat, they remain in your body for a long time.

Some scientists believe dioxins may be carcinogenic. Others think they are tumour promoters, which don't cause cancer but do increase the growth of any existing tumours. Because dioxins are so toxic, it's hard to study their long-term effects, as doses would have to be so low that some signs of toxic effects might be missed.

Most people are exposed to low levels of dioxins

Because they're so widespread in the environment, everyone is exposed to dioxins and will have some stored in their body. However, it's unlikely that this level of exposure will affect most people.

Even those exposed to dioxins under dirty industrial conditions have experienced relatively minor effects:

  • chloracne – a skin disorder that looks like bad acne
  • porphyria – a blood disorder that makes you sensitive to sunlight, amongst other things.

Exposure to dioxins is otherwise low – and dioxin levels in food are well below those that might lead to any toxicity.

Research by Food Standards ANZ

In 2004, Food Standards Australia New Zealand (FSANZ) reported on a survey of dioxin levels in foods in Australia. It concluded that the risk to Australians' health from dioxins in foods was very low.

All New Zealand research to date indicates the risk to New Zealanders from dioxins in foods and from the environment is at least as low as in Australia.

Declining dioxin levels in foods

Studies have shown that dioxin levels in breast milk, the environment and foods have been falling over the past few years in New Zealand. Similar tests in other countries have shown similar drops.

Download a 2011 report on dioxin levels in NZ – Ministry for the Environment website

Government monitoring of dioxins

The Ministry of Health has a whole-of-government coordinating role for dealing with public health issues arising from dioxins in New Zealand.

The Ministry for the Environment monitors and controls the use of dioxins as part of New Zealand's obligations under the Stockholm Convention on Persistent Organic Pollutants.

MPI deals with any issues related to dioxins in foods. We work closely with FSANZ to protect consumers from any risk posed by dioxins in food by making sure food standards are included in the joint Australia New Zealand Food Standards Code.

Find out more

Who to contact

If you have questions about dioxins in food, email info@mpi.govt.nz.

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