Wipe sampling can reach peak efficiency with certain parameters in place. Below are some recommendations for factors and considerations to review prior to and during your wipe sampling program.4
Determine the Goal of Wipe Sampling
Many healthcare settings have multiple goals for wipe sampling. Identifying these can help ensure you have the right tools and processes to achieve them. Some examples include:
- Compliance with occupational health guidelines
- Assessment of baseline levels of contamination of new equipment
- Determination of contamination levels on surfaces of safety equipment like CSTDs
- Evaluation of cleaning and safety program effectiveness
- Establishment of a comprehensive safe handling program
Starting with a goal can help determine your next steps. For example, to establish baseline contamination, one may need only single or single and subsequent wipe samples. However, to support a comprehensive safety program, you may need a regular schedule of wipe sample collection.
Inventory Chemotherapy Drugs and Other Hazardous Materials
Make a list of the hazardous drugs that are present in the facility. Then determine which drugs you want to sample. Your wipes must be able to pick up these drugs and create a sample that accurately reflects their presence in the environment.
Choose a Highly Efficient Sampling Method
Determine the combination of wipe and method that will achieve a high rate of recovery. It may be easier to collect from smooth, nonporous surfaces, but that may not always be possible. Try for a recovery rate of 90% before you approve a sampling method.4
Determine the Optimal Sample Size
OSHA guidelines recommend a sample size of 10 cm X 10 cm, or about the size of an individual's palm.8 After determining the level of a contaminant in a sample of this size, the health care facility can roughly calculate the amount of exposure during the course of a workday.
However, the 10 cm X 10 cm size may be too small for a large area and require multiple samples. It may miss components that are unevenly distributed across the surfaces. For that reason, you may want to take a series of larger samples, finding a balance between the cost of the process and the usefulness of the results.4
Record Sample Information
Before you begin your wipe sampling program, create a database to record the information. Transfer this data regularly after the program begins. Review the data fields with each entry to make sure you are capturing all necessary information.
Photograph or Sketch Sampling Areas
Keep a standard diagram, sketch, or photos of sampling areas. This will help eliminate confusion about the precise location of each sample's origins. This information can help show what parts of the facility are at higher risk for healthcare worker exposure.
Wipe Following Specific Pattern
To ensure accuracy of results, take the wipe sample the same way every time. That involves wiping the sample area in a particular pattern to eliminate changes in data readings that result from a lack of uniformity in sample taking.
Label and Pack Samples
Maintain a set procedure to pack and label samples that go for testing. Follow this procedure regardless of whether you use an external lab or test on-site. Keep a set chain of custody to avoid loss, mishandling, or contamination of samples.