1. What are nanomaterials?
Nanotechnology is the general term for designing and making anything whose use depends on specific structure at the nanoscale – generally taken as being 100 nanometres (100 millionths of a millimetre or 100 billionths of a metre) or less. It includes devices or systems made by manipulating individual atoms or molecules, as well as materials which contain very small structures.
Nanomaterials are usually considered to be materials with at least one external dimension that measures 100 nanometres or less or with internal structures measuring 100 nm or less. They may be in the form of particles, tubes, rods or fibres. The nanomaterials that have the same composition as known materials in bulk form may have different physico-chemical properties than the same materials in bulk form, and may behave differently if they enter the body. They may thus pose different potential hazards.
Aggregated nanomaterials also need to be assessed in this light as they may exhibit properties that are similar to those of the single nanoparticles, especially when they have an unusually large surface area for a given amount of material.
The number of products produced by nanotechnology or containing nanomaterials entering the market is increasing. Current applications include healthcare (in targeted drug delivery, regenerative medicine, and diagnostics), electronics, cosmetics, textiles, information technology and environmental protection. For example, nanosilver is appearing in a range of products, including washing machines, socks, food packaging, wound dressings and food supplements. Food supplements need especially close scrutiny.