Static Magnetic Field Limits
Patient and volunteers: | Lower Level (T) | Upper Level (T) |
---|---|---|
Trunk and head | 2.5 | 4 |
Limbs | 4 | 4 |
These are the HPA-RPD (was NRPB) static magnetic field restrictions on magnetic flux density. The lower level identifies exposures below which, except in exceptional cases, it is considered to be safe, and which may be exceeded under controlled circumstances. Below this level, no biological effects have been observed in humans, although reversible effects have been noted on ECGs. The upper level identifies exposures which, present evidence suggests, it would be inadvisable to exceed. (Note that the IEC levels are slightly different.)
Further reading on this topic:
Books: MHRA Guidelines p25-26