Good manufacturing practices (GMP) require that pharmaceutical manufacturers ensure their products are safe, pure and effective. HVAC systems and cleanroom design incorporate the use of HEPA and where necessary ULPA filters to impede growth of airborne contaminants.
Good manufacturing practices (GMP)
Airborne pharmaceutical contaminants represent a challenge. Like food processing, pharmaceutical manufacturing is governed by strict regulations with respect to air quality and hygiene. Good manufacturing practices (GMP) require that manufacturers, processors and packagers of drugs take proactive steps to ensure their products are safe, pure and effective. GMP are strongly recommended if not required in Canada, the USA, various countries within the European Union (EU) and in countless international pharmaceutical firms.
Bioaerosol control - Cleanrooms
GMP for heating, ventilating and air conditioning (HVAC) involve the determination of key parameters like temperature, humidity, pressure, filtration, airflow parameters and classification of cleanrooms in accordance with ISO 14644. HVAC systems must control airborne particles, dust and micro-organisms (or bioaerosols) by the use of high efficiency particulate air (HEPA) units and, where necessary, ultra-low particulate air (ULPA) filters. In addition, systems must maintain room pressure, relative humidity and temperature that will impede the growth of microbial contaminants on workers. Where air supplies for commercial office spaces require a mere 2 to 10 air changes/hour, cleanrooms demand 50 and sometimes up to 500 air changes/hour to dilute and reduce contaminant levels to acceptable concentrations.
HVAC systems - Product cross-contamination - Biohazards
Front-line HVAC systems with either “once through” air or partially re-circulated air
Recommended in facilities where there is potential product cross-contamination. Discrete operations like manufacturing, coating, tabletting, inspection, packing and bag handling need a Bag-in / Bag-out collector setup as a means to avoid cross contamination. Other critical applications include fume hoods and biological safety cabinets found in laboratories as well as biotechnology plants that manufacture pharmaceuticals and industrial enzymes from genetically-engineered crops (potential bio-hazards). .
Re-circulated HVAC systems
where large quantities of air may be required to promote unidirectional flow and air cleanliness, are suited for sterilized manufacturing (laminar airflow, minimal bioaerosol count, exceptionally clean return air).
Constant volume systems with terminal reheat (CVRH)
Next in line for pharmaceutical manufacturing areas. In reheat systems, humidity is always controlled, since dehumidification occurs at the cooling coil, and each zone requiring temperature control may have an additional reheat coil and thermostat. Airflow is also constant, which facilitates balancing and pressurization. For these reasons, reheat systems are simple to understand and function at optimum levels.
Control of fire / explosion hazards
Airborne pharmaceutical contaminants, depending on their chemical composition, may be combustible and explosive. To minimize the risk of fire in laboratories, low water content foam or “dry” systems with run-off containment decontamination are recommended pursuant to NFPA 45.