Section 4.2 of the guidance states that “adequate ventilation, air filtration and exhaust systems should be provided, where appropriate. These systems should be designed and constructed to minimize risks of contamination and cross-contamination and should include equipment for control of air pressure, microorganisms (if appropriate), dust, humidity, and temperature, as appropriate to the stage of manufacture. Particular attention should be given to areas where APIs are exposed to the environment”. If the API process is essentially a closed-system, this would minimize the need for establishment of air quality standards and specific area classifications.
