Measures of precaution for handling permanent magnets
1. Permanent magnets are generally brittle. This is due to the manufacturing process (powder metallurgy) and the chemical analysis. In order to avoid any damages it is necessary to handle them with care.
2. The high attraction forces of magnetised magnets (mainly from NdFeB) may lead to serious injuries of fingers and other parts of the of the human body. Therefore, magnetised magnets have to be handled with extreme care to prevent accidents.
3. Magnetic fields of permanent magnets may influence - depending on the distance - the function of technical devices. This also refers to cardiac pacemakers. Therefore, persons with pacemakers must not be exposed to magnetic fields.
4. Due to the possible impact of magnetic fields on technical devices, such as instruments, magnetised magnets are considered as hasardous goods in aviation. And have to be declared as such. Air transport of magnetised magnets is generally permitted only if a defined level of induction at a certain distance from the package is not exceeded. Detailed information is given by IATA. By means of shielding packaging (steel sheets) the rules can be met.
5. Permanent magnetic fields are able to destroy magnetic data carriers, such as floppy discs, hard discs and bank and credit cards. Therefore, contact of permanent magnets with these data carrier must be avoided.
6. Magnets of NdFeB are often coated to prevent corrosion. Damages to the coating must be avoided. Otherwise corrosion may occur and slowly destroy the magnet.