A specially constructed space environmentally controlled with respect to airborne particles (size and count), temperature, humidity, air pressure, airflow patterns, air motion, and lighting. ISO 14644-1 defines a cleanroom as "a room in which the concentration of airborne particles is con-trolled, and which is constructed and used in a manner to minimize the introduction, generation and retention of particles inside the room, and in which other relevant parameters — e.g. temperature, humidity and pressure — are controlled as necessary."