What magnets can and cannot damage
A fridge door, a chip card, a phone, an induction hob: each behaves differently near a magnet, and the difference is specific enough to check.
Browse all guides See what a fridge magnet is made ofWhat a fridge magnet can and cannot damage
Most things people worry about near a fridge magnet are unaffected. The exceptions come down to whether the item actually stores information as a magnetic pattern, and how strong the magnet is.
| Surface or device | Damaged by a fridge magnet? | Why | What to check |
|---|---|---|---|
| Fridge doors and other steel surfaces | No | This is what the magnet is designed to hold onto. A static field does not affect the steel or its paint or laminate coating. | Use the paperclip test to confirm the door is a magnetic grade of steel. |
| Contactless and chip bank cards | No | The chip and the contactless antenna store and transmit data electronically, so a fridge magnet has nothing to act on. | None needed |
| Magnetic-stripe cards, hotel key cards and older travel passes | Yes, if the magnet is strong and held close | The stripe stores data as a pattern of magnetic domains, and a neodymium magnet held directly against it can scramble that pattern. | Keep stripe cards away from neodymium magnets and magnetic wallet clasps |
| Phones and laptops with solid-state storage (SSD) | No | An SSD stores data electronically with no moving parts and no magnetic medium, so a fridge magnet cannot alter it. | Check whether an older device uses a spinning hard disk instead |
| Older laptop hard disk drives (HDD) and compasses | Can be, with a strong magnet held close | A hard disk platter and a compass needle both work by aligning tiny magnetic domains, and a neodymium magnet held near either can disturb or remagnetise them. | Keep strong magnets away from the drive casing or the compass housing |
| Pacemakers, other implanted devices, and induction hobs | Pacemakers: depends on the device; hobs: no | Some implanted devices have a magnetic switch that a close, strong magnet can trigger, while an induction hob senses cookware electronically and ignores a small magnet placed on its surface. | Check the safe distance stated by your device's manufacturer |
This is general guidance based on how each material or device works. For a pacemaker or other implanted device, confirm the stated safe distance with the device manufacturer.
Can a fridge magnet affect a pacemaker?
A pacemaker or implanted defibrillator can be affected by a magnet held close to it, because most devices contain a magnetic sensor that switches the device into a fixed operating mode when it detects a strong enough field. This is different from every other item on this page: the magnet does not need to touch the device, and the household fridge magnets covered elsewhere on this site are not the main concern. A promotional fridge magnet in hard ferrite has a low pull force and is normally kept at arm's length on a door.
There is no single safe distance
Device manufacturers do not publish one universal distance, because the sensor fitted and the strength of field it responds to both vary between models and between generations of the same model. This is a genuinely contested point in the sense that the guidance is model-specific, and a distance quoted for one pacemaker is not automatically correct for another. Treat any general number given outside a manufacturer's own documentation as unconfirmed for the device actually implanted.
Where to check your own device
Every pacemaker and implantable defibrillator is issued with an identification card at the time of implant, giving the model and the manufacturer's own stated minimum distance for consumer magnets and other electronic items. That card is the correct reference for the person carrying the device. Anyone without the card, or unsure which model they have, can ask the cardiac physiologist or the pacing clinic at the implanting hospital to confirm it.
What the NHS says
NHS guidance for people fitted with a pacemaker or defibrillator is to keep strong magnets, including those in some phone cases, bag clasps and executive desk toys, away from the device, and to raise any specific product with the cardiac team. A neodymium magnet, which produces a far stronger field than hard ferrite for the same size, is the type most likely to prompt that caution. Confirm the position for a specific device with the cardiac physiologist or the device's own manufacturer documentation before assuming any magnet is safe to carry or use nearby.
Magnetic therapy: what the evidence actually shows
Magnetic bracelets, insoles, wraps and “therapy” magnets are sold on a specific claim: that a static magnetic field, the kind produced by an ordinary permanent magnet just sitting there, relieves pain or improves circulation. That claim comes up often enough in relation to magnets generally that it is worth stating plainly. No credible clinical evidence supports it, and this site does not present it as if it might.
The regulatory position
The Advertising Standards Authority (ASA) has upheld complaints against advertisements making therapeutic claims for magnetic products, on the grounds that the claims were not backed by adequate evidence. Under the CAP Code, which governs UK advertising, a health claim has to be substantiated before it is published. Advertisers of magnetic therapy products have repeatedly failed to produce that substantiation to the ASA's satisfaction, which is why such ads are pulled or amended.
Why the claim fails on physics as well as evidence
A permanent magnet, whether it is the neodymium in a bracelet clasp or the flexible magnetic sheet on the back of a takeaway magnet, attracts ferrous metal at short range and does nothing beyond that range. The iron in human blood is bound inside haemoglobin, so there is no plausible mechanism by which an external field would act on it. That is the more basic problem with the therapy claim: it is not simply short of trial evidence, it describes an effect the material has no way to produce.
If you are weighing up a magnetic product sold on a health claim, the useful comparison is not the marketing copy but the ASA's published rulings on that category of advertising, which set out what was claimed and why the claim was not accepted.