I. General Standards (Pharmaceutical Factory / GMP mainstream)
Normal operating conditions (ordinary raw materials and excipients, low dust): HEPA high-efficiency filter: 12-24 months
High dust / high activity / toxic powders (anti-cancer drugs, hormones, sterile powders, fine powders of traditional Chinese medicine): HEPA high-efficiency filter: 6-12 months. Forced shortening
II. Not based on time, but on pressure difference (most accurate, GMP recognizes this)
Based on the initial pressure difference of the equipment:
When the final pressure difference reaches twice the initial pressure difference / the upper limit of the manufacturer’s calibration → immediately replace, don’t wait for the cycle
Daily pressure difference increase is fast: indicates a large dust load, replace in advance
III. Reference period for matching filters (companion notes)
Primary efficiency: 1-3 months of cleaning, 3-6 months of replacement
Intermediate efficiency: 6-12 months of replacement (protecting the high-efficiency filter, frequent replacement of intermediate efficiency = prolonging the life of HEPA)
IV. Key mandatory requirements (must be inspected by inspection agencies)
After each replacement of the high-efficiency filter: must conduct PAO leak detection + wind speed balance test + re-calibration of pressure difference, and retain the verification report.