Food safety is a prevalent concern in the commercial kitchen. One outbreak of food poisoning can destroy a business, so it is crucial to assure that foods do not contain harmful bacteria. Irradiation is a technology that is gaining popularity as an extra step in foodborne illness prevention, but many consumers doubt that the benefits of irradiation outweigh the potential human health and environmental impact.
Irradiation has been used in the medical field and by NASA for several years to provide sterile instruments and safe food. Also referred to as cold pasteurization, irradiation is the process of subjecting food to controlled amounts of radiation in order to kill harmful bacteria present both inside and on the surface of raw and ready-to-eat foods. Irradiation can also kill parasites and small insects, like fruit flies, to reduce spoilage.
Purposes of Food Irradiation
- Preservation. Irradiation can destroy microorganisms that cause foods to decompose and spoil, increasing the food’s shelf-life. Irradiation cannot, however, reverse spoilage once it has already begun.
- Sterilization. Foods sterilized through irradiation can be stored for years without refrigeration. This is a helpful application for hospitals, the military and NASA.
- Control insect damage. Irradiation is an alternative form of fumigation that does not employ insect sprays.
- Control food borne illnesses. Irradiation will kill E. Coli and Salmonella in or on raw meats and ready to eat foods. It has recently been approved as a treatment to kill pathogens on raw spinach and lettuce, too.
Three Different Technologies Used
- Gamma Rays. High energy rays from a radioactive substance are used to kill harmful microorganisms and pests in or on food. This technology has been used for more than 30 years to sterilize medical tools and kill cancer. Thick concrete walls and a water pool are used to protect operators from harm.
- Electron Beams (E-Beam). High energy electrons are propelled from a gun similar to how television tubes direct light to the screen. This technology uses no radioactive substances, but some shielding is required to protect operators.
- X-Rays. This newest form of irradiation uses machines that are approximately seven million times more powerful than medical x-rays to kill harmful organisms in or on food.1 Thick concrete walls are required to protect operators from the x-rays.
|Approval Year||Food||Reason for Irradiation|
|1963||Wheat flour||Control mold|
|1964||White potatoes||Inhibit sprouting|
|1986||Fruits and vegetables||Insect control, increase shelf life|
|1986||Herbs and spices||Sterilization|
|2008||Spinach and iceberg lettuce||Bacterial reduction|
*Information taken from the Center from Disease Control’s site on Food Irradiation.
Identifying Irradiated Foods
An internationally accepted symbol, called the Radura, is used to label irradiated foods. In addition to the Radura, a written description must be present in the packaging that reads, “Irradiated to destroy harmful microbes”. No labeling is required if only a minor ingredient, like a spice, has been irradiated.
Source of the Controversy
The controversy surrounding irradiation as a food safety method stems from the high levels of radiation used in the process. Each of the three technologies employed requires some form of shielding to protect workers from the harmful rays. This begs the question, if the beams are harmful to the operators, how harmful are they to the product? As with every controversial issue there is research and debate both supporting and opposing food irradiation.
Arguments for Irradiation
- Irradiated food does not significantly affect the price. Estimates show that irradiated vegetables can cost two to three cents more per pound while meats can cost up to five cents per pound more than non-irradiated foods. Many proponents feel this slight increase in cost is worth the extra shelf-life and improved food safety.
- The food does not become radioactive. Food irradiation is likened to getting an x-ray. The food passes through a radiated field, but since it does not touch the actual radiation source, it does not become radioactive.
- The food’s chemical composition and nutrition are unaffected. Irradiation produces virtually no heat, so the foods are not cooked or altered in any way that will affect their vitamin content or nutritional value. Freezing or canning foods may affect their nutritional value more than irradiation.
- Irradiated food does not cause mutation when ingested. Although a study conducted in India in the 1970s showed that chromosomal mutation occurred in rats, mice, monkeys and malnourished children that were fed irradiated wheat, no institution has ever been able to replicate these findings.2
Arguments Against Irradiation
- Irradiation can lead to environmental hazards. Radioactive water escaped from a Georgia irradiation facility in 1988 and cost the tax payers $47 million in cleanup costs.3 As more irradiation facilities are built, accidents like this can become more common. There is also the question of how to safely dispose of the hazardous waste produced by any facility that uses radioactive substances.
- Irradiation lowers the food’s quality. Recent studies indicate that irradiation can affect the protein structure of grains, like wheat. Flour made from irradiated grain was not as sticky, firm or bulky as non-irradiated flour. These physical changes can lower the volume and quality of baked goods.4
- There is no long term evidence that says irradiated food is safe. The longest study on human feeding was only 15 weeks. This is too short of a time to gauge the long-term effects of a lifetime diet that includes irradiated food.5
- Irradiation is not the answer to food safety concerns. Many opponents believe irradiation will become a cure-all for rising food safety concerns, allowing growers and regulators to become lax in their production processes.
What the Government Has to Say
- Irradiated food is safe to eat. The FDA states that irradiation does not significantly reduce nutritional quality or change the taste, texture or appearance of food.
- Irradiation facilities are safe for workers and communities. As with any other facility that uses radioactive materials, irradiation facilities are strictly regulated to prevent harm to the workers or surrounding community. The facilities are also constructed to withstand natural disasters, like earthquakes.
- Proper food handling is still needed. The FDA agrees that irradiation is not a cure for food poisoning; it is just one extra step in prevention. Proper food handling and preparation still needs to be observed both before and after irradiation takes place.