Carbon nanotubes (CNT) are about 100 times stronger than steel of the same diameter, which means that strength can be added to materials without adding much weight. Carbon nanotubes are also elastic, lightweight and highly conductive. These properties (and their long length) make the material ideal for use in many industries like plastics, batteries, electronics, 3D printing, construction and diagnostics.
Unfortunately, their shape makes them easily respirable and many studies have shown they can have a variety of negative effects on human health. Most of the ill effects occur in the lungs, but there are hazards to other organs, too, including the brain, liver and heart. The International Agency for Research on Cancer (IARC) has designated one type of MWCNT (MWCNT-7) as „possibly carcinogenic to humans (Group 2B).“ Due to the lack of evidence it is not possible to generalize the toxicity among the many different types of CNTs.