is undertaken in a cleanroom atmosphere where low levels of environmental pollutants such as particulates and airborne microbes are strictly minimised and most preferably eliminated.

The UK national building specifications, British Standard 5295:1989, specifically addresses "clean room" environments serving electronics manufacturers, as well as the pharmaceutical industry (the Pharmaceutical Industry has, for some time, worked to the ISO standard 14644 which is subtly different). Standard 5295:1989