What is Biological Validation by Design? A good validation method gives you a routine, repeatable way to verify the efficacy of your treatment system. Validation is not intended to replace the proven time, temperature and pressure metrics which are used to design a system. However, validation is used to compliment and prove efficacy. Biological Validation by Design, because we made validation a critical part of our systems.
Before addressing validation, it is important to recall the main functions of a biowaste treatment system. Sterilizing the waste stream can help accomplish the following objectives:
Validation of the efficacy of waste treatment systems can be a challenge. While upstream “product-side” equipment manufacturers are required to implement validation design features to verify safety, purity, and efficacy, waste treatment has traditionally been less stringent in this regard. However, due to the risks, our customers are increasingly requiring a similar level of assurance safety and treatment effectiveness.
PRI Bio understands that validation should not be an afterthought – and we have made it a critical element to the design of our biowaste systems, from the beginning. Every biowaste treatment system offered by PRI Bio has one or more design features that allow routine validation to take place.
Our validation design features are intended to achieve the following goals:
There are a wide variety of decontamination system technologies, each for varying applications and waste streams. Such as batch and continuous thermal treatment, or chemical treatment, for either affluent or solid tissue waste. We have developed a variety of validation design features intended to accommodate each of these treatment technologies.
Biowells: for thermal treatment systems, we incorporate biowells. Biowells are a small port/chamber which is built into the treatment zone that allows for a Self-Contained Bioindicator (SCBI) or a Spore Strip to be placed inside. A biowell creates an environment in which the bio-indicator can be isolated from the material being treated, but mirror the same thermal temperature curve, allowing for an accurate result. With this method, users can simply place the bio-indicator inside, run a normal cycle, and remove the bio-indicator once complete. Biowells can be incorporated in many types of biowaste treatment systems, such as batch or continuous effluent decontamination system, tissue digesters, and others. (Depending upon the system, we have some biowells which can be accessed from outside the vessel, and some from inside the vessel). Once retrieved, the bio-indicator (SCBI or Spore Strip) can be tested to verify treatment efficacy.
Suspension Tank & Inlet: all effluent decontamination systems can be validated using spore suspensions if desired. In order to make this process easier and less expensive, PRI Bio incorporates a combination of a specially-designed spore suspension tank and an inlet port and valve just prior to the treatment zone. This method allows users to validate to a 6 log reduction. The smaller suspension tank prevents users from having to fill the entire system with spores (which can be expensive). The inlet port and valve allow users to “hot switch” directly over to the spore tank while the system is running normal operation, fill the system with a measurable spore volume, and test the result at the discharge. This method is used in a continuous flow effluent decontamination system.
Direct Immersion: in chemical systems (for example), spore strips offer an accurate method to validate the treatment efficacy, because they allow the bacteria on the strips to come into direct contact with the treatment chemicals. For these types of systems, we offer a port on the treatment tank, where a metal, porous spore strip holder can be lowered into the system, attached to a chain and cap. This spore strip holder allows the chemicals to flow freely through it. Once a treatment cycle is complete, the spore strip holder can be retrieved, and testing can be done to confirm efficacy. This method requires a special spore strip designed to be used in liquid applications, specifically for chemicals.
Data Logging: every PRI Biosystem is engineered with instrumentation throughout the system to monitor critical components such as temperature, pressure, flow, level, and mechanical components such as valve positioning, pumps and more, which provide feedback to a control system. PRI Bio also offers a reporting software (called Batch Report) that runs on a dedicated PC, networked to the main control panel. This system serves as a constant feedback mechanism to give end-users confidence in the efficacy of the system. The system displays a constant log of critical thermal data during a cycle. At the conclusion of a batch or cycle period, the Batch Report system creates a table and graph of the pertinent data and auto-archives this as a PDF for future reference.
The control system also provides alarms and fail-safes if the target is not achieved. For example, if target temperatures or target flow rates are out of specification, the system will alarm and enter a safe mode, preventing discharge, and allowing operators to intervene and troubleshoot.
Below is a reference chart indicating which validation method is used by each of our systems: