ENVIRONMENTAL MONITORING PERFORMANCE ANALYSIS: A COMPARATIVE STUDY OF CLASS C AND CLASS D CONTROLLED ENVIRONMENTS

Monitoring and controlling of clean area environment is of paramount importance to ensure product safety and quality. This comprehensive analysis evaluates environmental monitoring (EM) data from Class C and Class D controlled environments in pharmaceutical manufacturing, utilizing Active Air (AA), Passive Air (PA), and Contact Plate (CP) or Replicate Organism Detection And Counting (RODAC) surface samples. The study aims to identify contamination trends, anomalies, and compliance with ISO 14644-1 and EU GMP Annex 1 standards. Results reveal unexpected findings: Class C Active Air (43 CFU/m³) and RODAC (3 CFU/plate) overall averages are higher than Class D Active Air (34 CFU/m³) and RODAC (2 CFU/plate), respectively, deviating from expected cleanroom classification. Class D Passive Air (22 CFU/plate) is higher than Class C (17 CFU/plate), aligning with expectations. Persistent hotspots were identified in Class C (e.g., location labelled “AA C 12 NG0”AA averages± Standard Deviation (SD): 67.33±17 CFU/m³), indicating localized control failures, while Class D showed extreme individual spikes (e.g., AA D 99 Ac: Max 171 CFU/m³). Sporadic contamination events in Class C suggest transient breaches, necessitating root-cause investigations. The study also highlights limitations of Class D monitoring, which obscures temporal trends and risks missing critical excursions due to long intervals between samples. Recommendations include targeted engineering assessments for high-load zones, enhanced Standard Operating Procedures (SOPs) for cleaning and gowning, adoption of real-time biofluorescent particle counters to replace manual sampling, and increased monitoring frequency in Class D hotspots. Peer Review History: Received 3 June 2025; Reviewed 11 July 2025; Accepted 17 August; Available online 15 September 2025 Academic Editor: Dr. Marwa A. A. Fayed, University of Sadat City, Egypt, [email protected] Reviewers: Dr. Dennis Amaechi, MrsFoluBabade Mini Estate , Flat 5 by Old Soldiers Quarter, Sabongari/Bwari, Abuja- Federal Capital Territory, Nigeria. [email protected] Dr. Esther Marguerite Chase DJANGA, Faculty of Medicine and Biomedical Sciences. Department of Public Health. University of Yaoundé I, Cameroon. [email protected]