GMP-Compliant Humidification in Cleanrooms

In GMP-regulated cleanrooms, controlling air humidity is critical for employee safety, product quality, and process reliability. Dry air can irritate mucous membranes, increase electrostatic charges, and reduce disinfectant efficacy, while certain products may have specific humidity requirements. Typically, relative humidity is maintained above 40%.

In sterile zones (Grades A, B, and sometimes C), steam humidification is preferred. Regulatory guidelines define Pure Steam quality, with condensate meeting Water for Injection (WFI) standards. Practical implementations often align condensate quality with production water (Purified Water or WFI) and are justified through risk assessments considering cleanroom classification, product handling, electrostatic discharge, and microbiological safety.

In Grade D or non-sterile areas, filtered plant steam with food-grade approval may be used, while adiabatic humidification with pressurized water poses microbial risks if systems remain idle. Selection of a humidification method requires balancing microbiological safety, technical feasibility, and economic considerations, ensuring proper documentation for inspection readiness.

23-09-2025