by Hank Rahe
Developing a knowledge base to service the complete array of contamination-control issues is a formable task. The key is to remember that no one knows it all. Rather, individuals who are successful in delivering solutions have a network of resources with in-depth knowledge in very focused areas.
The four areas of expertise for delivering contamination-control solutions include an understanding of containment technologies, risk assessment, ergonomics and the process.
Containment technologies consist of several specific means of separating the worker from the danger created by the materials being handled in the process. Each of these individual technologies has degrees of protection based on the individual application.
Within the individual technology there are sub sets that can have a significant impact on effectiveness and cost. Selecting the technology is the beginning and it is critical to have technical support that can develop the proper level of technology rather than simply selling the products they represent. Selecting the correct technology can begin only after the goal or exposure limit of protection has been identified. Without the target it is difficult to design a cost-effective system.
Technical support begins when you understand the limits the containment technologies can provide in protection levels. Each technology has limited capabilities based on the configuration of the individual components that make up that technology. The exposure limit can change if you use different configurations of components.
Often there may be more than one type of component that can be selected to accomplish the same task, such as bag rings or airlocks used in barrier isolators. Component selection impacts the capability and cost of the overall containment system. Never assume that a higher level of protection automatically means increased cost.
Risk assessment should be used to determine if the risk actually exists and the extent of containment technology required to reduce the risk. Don't assume that equal risk exists throughout the entire handling of hazardous material when the handling involves a variety of operations. If possible, the potential for risk should be measured through surrogate testing.
Understanding the key areas of expertise and putting together a team that can deliver these elements to your project is the difference between containment success and failure.
Concentrations of hazardous materials present in the worker's breathing zone, frequency of potential exposure and potential for systems to fail should be considered in the risk evaluation. Systems should be developed to be failsafe. Risk assessment saves time and helps in providing more functional solutions.
Ergonomics determine the success or failure of most containment systems. If the system has not taken into consideration how workers will interact and make the interactions as functional as possible, the workers will develop alternative methods of accomplishing the task. Written procedures or work practices should enforce the ergonomic evaluation. This formalizes the correct way of using the containment devices.
The process or activity that is taking place within the containment is the key element. Understanding the process in terms of how workers interact with the equipment and hazardous materials drives the selection of acceptable technologies that meet the exposure limit. There may be several possible configurations capable of meeting the exposure limit goal and each should be evaluated to understand which would best fit the process constraints.
Lack of process integration with the containment system is the biggest reason for failure of containment projects. Performing the process activities in a containment system limits the manipulations, which means that each interaction must be defined and the proper interaction technology provided in the containment system. Interaction includes not only the physical interactions but also ability to view critical process activities.
Hank Rahe is director of technology for Containment Technologies Group and is a member of the CleanRooms Editorial Advisory Board.