The recommendation describes nanomaterials as materials whose main constituents have a dimension of between 1-100 billionth of a meter (1-100nm).

The commission described the move as “an important step” towards the greater protection of citizens, since it defines which materials will need special treatment in specific legislation.

Claiming that the EU is the first to issue one clear definition, European Environment Commissioner Janez Potocnik said: “Industry needs a clear, coherent regulatory framework in this important economic sector, and consumers deserve accurate information about these substances.”

Nanomaterials are already used in hundreds of applications and consumer products including clothing. But as uncertainties remain about the risks they pose, a clear definition should help ensure that the appropriate chemical safety rules apply.

The definition will be reviewed in 2014 in the light of technical and scientific progress.