Training and SOPs for surface sampling:

• The new USP standard states, “It is important that personnel are trained and competent in air and surface sampling procedures to ensure accurate and reproducible sampling.” How can you perform surface sampling competency you might ask? Click here to learn about the Enverify™ Surface Sampling Competency kit that enables you to objectively demonstrate competency in surface sampling for the first time.

• Each facility must develop and implement procedures for surface sampling. These procedures will need to include, at a minimum the topics outlined on this page. Importantly, Section 17 of USP <797> (01-Nov-2023) states that a designated person MUST ensure that “personnel demonstrate competency in performing every procedure that relates to their job.” This means that if the personnel are doing surface sampling, they must demonstrate competency in surface sampling.

Where to sample:

• Sample each classified area. This includes each room, interior of each ISO class 5 PEC, and pass through chambers connected to classified areas.

• The following should be sampled - sample equipment contained in the PEC, staging areas near the PEC, and frequently touched surfaces.

• Sample the direct compounding area (DCA) as part of media-fill aseptic manipulation competency testing.

When to sample:

• Category 1 and Category 2 CSPs – must be performed initially and at least monthly

• Category 3 – must be performed initially, at least weekly, and at the end of each batch

• Perform sampling during dynamic operating conditions at the end of compounding activity, but before cleaning and disinfection.

• Following certification or service of facilities or equipment, in response to problems, trends, or changes to procedures.

What surface sampling device(s) to use:

• Flat surfaces: surface sampling collection devices containing general microbial growth media (e.g. TSA) such as contact plates, paddles, slides that also include appropriate neutralizers for the disinfectants used. Devices must have a raised convex surface and each lot must have passed criteria for growth promotion, pH, and sterilization.

• Irregular surfaces: swab sample collection devices wetted with appropriate neutralizer for the disinfectants used.

How to sample:

• Aseptically remove cover from sampling device. Use a rolling motion to press the growth media surface onto the surface to be sampled.  Clean and disinfect the sampled area after sampling.

Note: surface sampling recovery of microbes can be affected by several key factors including: contact time, pressure, rolling motion, plate wetness, and growth media composition. It is important to understand how each of these factors can impact to your personnel’s sampling performance. To learn more about this topic, reach out to us.

• Cover and invert plates for incubation. Incubate at 30-35°C for >48 hrs, followed by incubation at 20-25°C for >5 days.

Data evaluation and documentation

• Evaluate CFU levels against action levels in Table 1.

• Compare results to previous data to identify trends

• Procedures, test results, and corrective actions must be documented and records appropriately maintained.

• If the thresholds listed below are exceeded, determine the genus of the microorganism, and perform an investigation and take appropriate corrective actions.

  Action Levels for Surface Sampling

  ISO Class 5, >3 CFU/media device

  ISO Class 7, >5 CFU/media device

  ISO Class 8, >50 CFU/media device

Learn more about how to accomplish Surface Sampling Training and Competency