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Hazards Of Ferrite Magnets


Magnets are incredibly useful and fun, but they aren’t without their hazards. Please read the below before handling magnets and remember, safety first!


Place two magnets close to each other, even small ones, and they will attract and jump together. This is the most common cause of broken magnets and it is possible that one or both magnets could chip or shatter.

Due to the force exerted by the magnets it is possible that chips may fly off at high speed into someone's eye, therefore we advise that when handling more than one ferrite magnet that you wear eye protection. Chips and broken magnets can also be quite sharp, so treat them as carefully as you would broken glass.


Children should be supervised at all times when handling or playing with magnets and small children likely to swallow them should be kept away from them at all times.

If more than one magnet is swallowed, they can get stuck and pinch the digestive tract causing major swelling and even life-threatening injuries requiring surgery.

Larger magnets can crush fingers and break bones. Always keep magnets out of the reach of unsupervised children.


When larger magnets are brought close enough together they can have a surprising amount of power. Fingers are quickly caught between them which can cause blood blisters or cuts. Wear gloves when handling larger magnets and always handle with care.

The maximum size of ferrite block is 150mm x 100mm x 25mm and these, especially when stacked in a pile of several magnets, can be very strong indeed and the chances of crushing finger tips are high.


Keep a safe distance (at least 20cm) between your magnets and all objects that can be damaged by magnetism. Items such as mechanical watches, heart pacemakers, CRT monitors and televisions, credit cards, diskettes and other magnetically stored media such as video tapes are all susceptible to powerful magnets


There is a general lack of understanding regarding how magnets can affect heart pacemakers.

At first4magnets.com we sought advice from a specialist and the following information represents our best knowledge regarding how heart pacemakers are affected by magnets.

Lindsay Grant (BSc CEng FIET CSci FIPEM ARCP) is a Consultant Clinical Scientist and Head of the Clinical Engineering Department of Medical Physics & Bioengineering at the Royal United Hospital.

Lindsay kindly gave us this advice: “The operation of heart pacemakers will be affected by the close proximity of a magnet. Magnets can set a pacemaker working in a way that is not suitable for the pacemaker user and that might affect their health. This change will stop when the magnet is removed.”

She added: “The background to this is that magnets are used to put pacemakers into a mode of working that does not respond to the patient's own heart rhythm. We regularly use magnets in our pacemaker clinics to change the working of the pacemaker, to see how it is operating. Each pacemaker manufacturer uses the 'magnet response' of a pacemaker in a different way, so it is impossible to be more precise than the above statement.

“Some manufacturers have a response that makes the pacemaker pace the heart at 100 beats-per-minute or faster. The pacemaker will not usually synchronise with the natural heart beat when a magnet is applied. Although in 20 years’ experience of putting magnets on pacemakers, I have never had a problem, it is theoretically possible to trigger a life threatening heart rhythm by doing so.”

First4magnets.com thank Lindsay for this clear and valuable advice.


Ferrite magnets can be secured in place with adhesive or in some cases, with countersunk screws. Magnets are sintered and are therefore extremely hard and brittle. You should never attempt to cut or drill into a magnet unless using diamond tooling and coolant.


Millions of people worldwide wear magnets to promote health and wellbeing. We have found no evidence at all of detrimental effects of magnets on people or animals – many people actually believe it that they promote health and accelerate healing.

Further Information Regarding Ferrite Magnets

How to buy Ferrite Magnets