UVGI Disinfection Theory

Abstract

The disinfection of surfaces is perhaps the simplest and most predictable application of ultraviolet germicidal radiation. UV is highly effective at controlling microbial growth and at achieving sterilization of most types of surfaces. Early applications included equipment sterilization in the medical industry. Modern applications include pharmaceutical product disinfection, area disinfection, cooling coil and drain pan disinfection, and overhead UV systems for surgical suites. Such applications often involve using bare UV lamps and as such there may be UV hazards associated with them. Cooling coil disinfection with ultraviolet light has proven so effective that such installations often pay for themselves in short order. The use of UV is fairly common in the packaging industry and in the food processing industry where it is sometimes used for irradiating the surfaces of foodstuffs. Lower room UV systems are not common although they have been used in hospitals in the past. This chapter provides basic design information for each type of surface disinfection system based on theoretical analysis and field testing results. Good design practices are discussed and general guidelines are provided.