Pendants and bracelets sold as protection against 5G radio waves are radioactive, officials in Europe have warned.

'Quantum pendants' and 'negative ion' jewellery meant to protect wearers against the alleged harmful effects of cellphone signals have been recalled by the Netherlands' Authority for Nuclear Safety and Radiation Protection (ANVS).

"The level of radiation measured is low and risk of health problems is low too. However, it cannot be completely ruled out that wearing these products continuously for an extended period may prove harmful to your health in the long-term," it said on Thursday. 

"The ANVS has informed all known vendors of these products in the Netherlands that their sale is prohibited and that they must stop trading in these products immediately."

Ten products have been singled out by the authority, including brands of sleep masks, bracelets and necklaces - some marketed at children. They're sold under brand names including 'Energy Armor' and 'Magnetix'. 

5G signals are non-ionising - meaning they can't remove electrons from atoms. At the strengths used by cellphone networks, 5G signals are completely safe, according to scientists and the World Health Organization. 

Ionising radiation is the kind that can harm, even at low levels - and ironically, the kind put off by the illegal bracelets and necklaces sold by online scammers. 

The ANVS is urging owners not to just chuck their radioactive junk in the rubbish bin - saying it needs to be disposed of properly by professionals. 

5G technology, like 4G before it, has been the subject of numerous conspiracy theories - such as being responsible for spreading COVID-19.