Immediate danger to life: call 999 or 112.

UK Ready is an independent information site. Current official instructions for your area take priority over this general guidance.

Sheltering from radioactive fallout

Sources checked 13 October 2026

Action summary

1. Bring the household together and check urgent injuries and essential equipment.
2. Close openings and reduce outside air entering as instructed.
3. Put water, safe food, medicines, a radio, lights and toilet arrangements close by if available within the building.
4. Keep contaminated shoes, outer clothes and used cleaning materials sealed and away from people and pets.
5. Record official updates and the time of each message.

Fallout consists of radioactive material deposited after a nuclear detonation. Radiation can also arise from a reactor accident or other source. These are different events; a release from a power station does not turn it into a nuclear weapon. Do not infer conditions in one event from guidance written for another.

The protective principle is to reduce time exposed, put distance between yourself and contaminated surfaces, and use substantial building material as shielding. Inside a safe building, use a central room or a suitable basement away from outside walls, roof exposure and windows. Avoid unsafe basements in flood conditions and do not block escape routes or place heavy improvised loads on floors.

Set up your shelter space

1. Bring the household together and check urgent injuries and essential equipment.
2. Close openings and reduce outside air entering as instructed. Avoid deliberately making a room airtight; do not block combustion flues, oxygen equipment or safety-critical systems.
3. Put water, safe food, medicines, a radio, lights and toilet arrangements close by if available within the building.
4. Keep contaminated shoes, outer clothes and used cleaning materials sealed and away from people and pets.
5. Record official updates and the time of each message.

UKHSA says sheltering after a radioactive release may be needed for one or two days and can last longer if a release continues. This is an indication of possible duration, not an automatic release time after a nuclear attack. Do not assume it is safe outside after 24 or 48 hours, after a change of wind, or because dust is no longer visible.

A face covering can help reduce breathing in particles during a necessary movement or cleaning task, but it does not shield you from penetrating radiation. A raincoat, foil blanket or consumer 'radiation' product is not a substitute for shelter. Avoid using radiation decay rules or a consumer meter to declare your house, road or food safe.

Leaving shelter: Follow official evacuation routes and timing when given. If immediate fire, collapse, flooding or a medical crisis makes remaining dangerous, seek help and move to safer nearby protection as necessary. Tell responders about people unable to move unaided.

Sources

• UK Health Security Agency: What to do in a radiation emergency
• US Centers for Disease Control and Prevention: Nuclear Blasts Frequently Asked Questions
• US Centers for Disease Control and Prevention: Food Drinking Water and Medicine Safety in a Radiation Emergency
• US Centers for Disease Control and Prevention: How to Make Water Safe in an Emergency

All text-only guides · Full website