230.0.0.2R1. For the purposes of subparagraphs a and b of the first paragraph of section 230.0.0.2 of the Act, a special-purpose building is a building the working areas of which are designed and constructed to have a displacement in any direction of not more than 0.02 µm and to have, per 0.028 m3 of interior airspace,(a) not more than 350 airborne particles of a size equal to or less than 0.1 µm in diameter and no airbone particle of a size greater than 0.1 µm in diameter;
(b) not more than 75 airborne particles of a size equal to or less than 0.2 µm in diameter and no airbone particle of a size greater than 0.2 µm in diameter;
(c) not more than 30 airborne particles of a size equal to or less than 0.3 µm in diameter and no airbone particle of a size greater than 0.3 µm in diameter; and
(d) not more than 10 airborne particles of a size equal to or less than 0.5 µm in diameter and no airbone particle of a size greater than 0.5 µm in diameter.