Radiation from hands-free mobile phones can be reduced to virtually zero by a simple tiny magnetic bead which costs a few pence, a government adviser says. Professor Lawrie Challis said clipping a ferrite bead on kits stops the radio waves travelling up the wire and into the head.

Do ferrite beads stop radiation?

RF Safe has a very simple and inexpensive way to reduce microwave radiation from traveling up a headset's wire into the brain. It's a special material composition, a ferrite bead. ... Ferrites are used in many consumer electronics to prevent interference from disruptive electromagnetic radiation.

How effective are ferrite beads?

For effective power supply noise filtering, a design guideline is to use ferrite beads at about 20% of their rated dc current. As shown in these two examples, the inductance at 20% of the rated current drops to about 30% for the 6 A bead and to about 15% for the 3 A bead.