Correlation between Environmental Monitoring and Product Bioburden

Environmental monitoring (EM) has long been used by manufacturers to evaluate the potential microbiological impact from the manufacturing environment on the product produced therein. In the 1890s, Fred B. Kilmer pioneered the principles of asepsis and the need to institute policies to protect a product from environmental particulates and/or microorganisms. These practices are now commonplace for pharmaceutical and medical device manufacturing. EM and product bioburden screening programs are required by international regulations to demonstrate the manufacturer maintains control over the manufacturing process. However, no published reports have appeared regarding the correlation between viable microorganism data in an EM program and the effect on product bioburden. Industry experience routinely speculates that no clear connection exists between microorganisms in the environment and microorganisms on a product at the completion of manufacturing. Typically, it is postulated that vectors that introduce microorganisms affecting the environment (e.g., surface cleanliness, static control) are different from those that directly affect product bioburden (e.g., raw materials, product handling). To evaluate this industry hypothesis, five years of EM and product bioburden data were evaluated to determine whether a correlation could be determined. Graphically, there seemed to be some correlation and possible bioburden prediction value; however, the data did not demonstrate a statistically significant correlation between bioburden and EM monitoring programs performed using current industry standards and guidelines.