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Surface & Personnel Testing

Surface & Personnel Testing

Surface and personnel testing are essential methods used to collect, detect, and assess the levels of various microorganisms in order to evaluate the effectiveness of disinfection routines in both critical and non-critical manufacturing areas. The hygiene standards maintained in a production environment are directly linked to the microbiological safety and overall quality of the finished products. To ensure consumer protection, several regulatory agencies, including the European Union’s cGMP, U.S. FDA Aseptic Guidance, and USP <1116>, have developed standardized methods to monitor and control microbial contamination. These guidelines are applied to industries such as pharmaceuticals, cosmetics, food, and beverages, ensuring that manufacturing practices adhere to strict microbial safety protocols to safeguard public health.

Overview

Traditional Surface Monitoring

To ensure the safety of a product, it is key to monitor the cleanliness of surfaces in the production area, such as tables, walls, or doors, and in isolators and cleanrooms. These surfaces and areas must be free of microorganisms to reduce the risk of cross-contamination, which could make the product unsafe for use or consumption. Aseptic and controlled environments require frequent monitoring by surface sampling methods:

  • Flat surfaces: Can be sampled by pressing contact plates or slides on the surface with uniform and steady pressure for a few seconds. The sample plates or slides are then incubated for the microorganisms to grow, before enumerating the grown bacterial cultures. The incubation conditions differ depending on microflora composition and regulatory requirements.
  • Curved surfaces and hard-to-access areas: Can be monitored by the swab test method.

Rapid Surface Monitoring

Manufacturers who require fast results can use rapid methods to quantify microbial residue post-sanitation and pre-operation. Such methods include:

  • Colorimetric-based assays: Require no instrument.
  • Sampling swabs: Require an instrument reader, such as a luminometer.

The need for rapid quality control methods is especially high in the food and beverages industry due to the perishable nature of their manufactured goods. It is also necessary in other industries to keep up with increasing production demand.

Personnel Monitoring

Personnel monitoring is performed to ensure the maintenance of the sterile environment. The majority of contamination within a facility can be traced to humans working in cleanrooms. Specific procedures for gowning and sterilizing need to be followed by the personnel before entering and exiting the aseptic cleanroom.