Why do people in Switzerland receive iodine tablets?

If you receive a mystery package out of the blue from the government and find a collection of iodine tablets, don’t panic! This is just one of the ways Switzerland prepares for nuclear accidents and it is a precautionary measure. Here’s what expats need to know about the Swiss state's special delivery.

What are iodine tablets and what do they do?

Potassium iodide tablets, also known as iodine, are tablets quite similar to table salt. The tablets themselves, if taken at the right time and in the correct amount, are able to block the thyroid gland’s uptake of radioactive iodine, in the event of a nuclear incident.

Once taken, the "blocked" thyroid is unable to absorb harmful radioactive iodine that may be inhaled or swallowed by someone exposed to radioactive substances, reducing the risk of thyroid cancer and other diseases.

However, you should not take these tablets unless advised to do so.

Who gets iodine tablets in Switzerland?

Iodine tablets are given to residents who live within 50 kilometres of a Swiss nuclear plant. Currently, there are three nuclear plants in operation: Beznau, Leibstadt (Canton Aargau) and Gösgen (Canton Solothurn).

This means that those living in Zurich, Aarau, Basel, Zug, Lucerne, Winterthur, and Schaffhausen, as well as many other cities and cantons receive iodine tablets from the federal authorities. The Swiss government has also ordered that every resident be given iodine tablets within 12 hours of declaring an emergency.

What do Swiss iodine tablets look like?

Iodine tablets are sent to every person registered in Switzerland (including children) within the 50-kilometre radius of a nuclear power plant by post, free of charge. They are sent in small, rectangular white cardboard boxes, which should only include your full name and address. Once opened, the white and orange packets with the Swiss cross on the bottom contain 12 tablets.

How should you store iodine tablets (and when do they expire)?

Iodine tablets must be kept in their orange and white packaging until use. They should be stored at room temperature (15 - 25 degrees celsius) and away from children. Iodine tablets take around nine to 10 years to expire, but the government will send fresh replacement tablets before they do - the last resupply occurred in October 2023.

When are you supposed to use iodine tablets?

In the event of a nuclear accident or conflict, residents are advised to take the tablet once the threat has been confirmed, either by radio, television or through the Alertswiss app. Along with the tablets, the government also advises those affected to remain indoors and hide in a cellar or shelter. While every resident over two months old should be issued with the tablets, they are only recommended for people who are under 45 years old - the group most at risk of thyroid cancer.

Do not take the tablets before the threat is confirmed, as consuming too much iodine at the wrong time can cause nausea, vomiting and abdominal pain. Always be sure to read the instructions that come with the iodine tablets.

While the tablets do offer protection from radioactive iodine - one of the byproducts of nuclear power - they do not protect against other radioactive material. Poisoning by Cesium-137 and Strontium-90 - two of the deadliest byproducts of a nuclear accident - is not prevented by iodine tablets.

How likely is a nuclear incident in Switzerland?

While this may seem quite doom and gloom, authorities made clear that the chances of a nuclear incident in Switzerland remain very low. Speaking to Swissinfo in 2019, the association of nuclear power station operators, Swissnuclear, said, “Swiss nuclear power plants have been designed, built and regularly retrofitted in such a way that they can cope with severe accidents.”

Swiss nuclear plants are heavily regulated and monitored by the government to ensure an accident remains unlikely. According to Swissnuclear, “Thanks to multiple and independent safety systems, it is extremely unlikely that a serious accident will occur.”

For more information about iodine tablets, please visit the official government website.