After a radiation or chemical release, being inside a solid building is usually the best protection. Remember three steps: get in, stay in, tune in. Most of the danger in the first hours comes from particles and gases outside. Walls, roof and distance from the outside keep most of it away from you.
Get in
- Go inside the nearest solid building straight away. Do not wait to reach home if it is far.
- Bring children and pets inside. Do not go out to collect children from school; schools have their own plans.
- Move to the centre of the building, or to the basement. In a block of flats, the middle floors and the core of the building are better than the top floor or rooms with outside walls.
- Stay away from windows and outer walls.
Close up the building
- Close all windows, doors and vents.
- Switch off ventilation, air conditioning and fans that bring in air from outside. Close the fireplace damper.
- Seal gaps around windows and doors with wet towels or tape if you are told to.
- Fill containers with tap water while it is still safe. Later, the authorities will tell you whether tap water is drinkable.
If you were outside
Fallout and chemical dust stick to clothes, skin and hair. Removing them removes most of the contamination.
- Take off your outer clothing and shoes as soon as you are inside, ideally at the door.
- Put them in a plastic bag, close it and keep it away from people and pets.
- Shower with warm water and soap. Wash your hair with shampoo only, no conditioner, which can bind particles to hair.
- Wipe your eyelids, ears and nose with a damp cloth if you cannot shower.
- Put on clean clothes that were stored indoors.
Help children and pets the same way. Do not scrub hard or scratch the skin.
Stay in
- Stay inside until the authorities say it is safe to leave or to evacuate. This may take a day or more.
- Eat stored food and drink sealed or stored water. Food rations need no cooking.
- Do not go outside to check the situation, smoke on the balcony or walk the dog.
- If you must go out briefly, wear an FFP3 mask, cover your skin and change clothes again when you return.
Tune in
- Listen to official news on a crank radio, TV or official phone alerts.
- Follow only official instructions. Ignore rumours on social media.
- Keep your phone charged and the line free for emergencies.
Potassium iodide
Potassium iodide tablets protect only the thyroid, and only against radioactive iodine. They do not protect against other radiation or chemicals.
- Take them only when the authorities instruct you to, and only in the dose they give for your age.
- Do not take them as a precaution or “just in case”. Taking them too early, too late or too often brings risks and no benefit.
- People with thyroid conditions or iodine allergy should ask a doctor in advance.
Prepare in advance
- Choose the room you would use: central, few windows, ideally in the basement.
- Keep water, food, a radio, a headlamp, medication and masks there or nearby.
- Learn how to switch off your ventilation, air conditioning and extractor fans.
- Find out whether you live near a nuclear power plant or chemical plant, and what your local emergency plan says.
Always follow your local authorities. Their instructions take priority over this guide.