Cleanroom Wiper Testing: Good News and a Little Guidance

Wipers are necessary to cleaning any cleanroom, but they need to be tested to ensure they’re non-linting. Here is some information as well as good news on testing.

Wiper-based cleaning is one of the most effective methods of cleanroom cleaning. Test data to confirm that wipers are non-linting is a USP 797 requirement. However, there is no recognized test, procedure, or recommended practice that will determine the right wiper for a specific cleanroom, process, or activity. So what do you need to know about finding the right wiper?

There is a recommended practice for determining wiper contamination characteristics, so this is a good place to start. These are found in the IEST-RP-CC004.3, Evaluating Wiping Materials Used in Cleanrooms and Other Controlled Environments.  Here you’ll find descriptions of contamination characteristics and contamination levels like:

  • Particle
  • Fiber
  • Non-speciated extractable matter
  • Ionic contaminant

In addition to these factors, however, are those aspects that are difficult to quantify, like:

  • User process needs
  • Impact of activities (cleaning spills and surfaces, holding manufactured parts and pieces, etc.)
  • Impact to product yield
  • Impact to manufacturing costs

All of these elements factor into what will provide the most appropriate cleaning and contamination control. So when it comes to testing and documenting, how do you know what type of wiper to start with? Here are three considerations for choosing the wipers to test:

  1. Wipers used in ISO Class 3-4 cleanrooms are usually knit polyester with edges that are most likely sealed but can be cut if the durability process allows it.
  2. Wipers used in ISO Class 5-8 are usually nonwoven polyester/cellulose.
  3. Both contamination and performance characteristics, like sorption capacity and rate, impact selection decision. Sorption capacity = amount of liquid a wipe can hold; sorption rate = how fast a wiper can sorb liquid. Your particular needs are based on your cleaning solvent/solution and protocol.

While validating wipers without a definite test or guideline is frustrating, there is good news. A group of wiper manufacturer industry experts, cleanroom consumable distributors, and end-users of wipers are making headway. This group is the IEST’s Working Group 4, and they are revising the recommended practice: Evaluating Wiping Materials Used in Cleanrooms and other Controlled Environments. Part of their revision is dedicated to standardizing the test methods used to evaluate wipers.

If you need cleanroom validation or certification, or you have questions about either process, call Gerbig Engineering Company. We perform these services as well as manufacture cleanrooms. Contact us at 888-628-0056 or

Do Your Cleanroom Employees Have what they Need to be Innovative?

If you want your employees to think outside the box, shouldn’t you be doing the same? Here’s what a leadership expert has to say.

The strongest leaders know that without innovation, business is doomed. An environment like a cleanroom and the resulting products are in and of themselves innovative. To build on this can mean leaps and bounds for future success.

What do employees need to let their innovative juices flow? Maxine Attong, a seasoned corporate coach with an impressive résumé, offers a suggestion that may surprise you. She attributes the level of an employee’s innovative ideas to how safe he or she feels.

She’s not talking about physical safety.

Attong discusses the importance of feeling safe to express opinions, ideas, and feelings without judgment or repercussion. She says,

“In order to take risks, which is the foundation of innovation and subsequent rewards, a team member has to feel safe… Anyone who has ever been in a classroom or company meeting knows the potential risk of making an out-of-the-box statement, which could be seen as silly, frivolous, or ignorant — or as a groundbreaking insight. Without a sense of safety, most employees will decide to silence an unconventional statement that could risk their standing.”

Her suggestion is to create a safe space – the “office Vegas,” if you will; what happens there stays there – in the workplace. She notes that no matter how structured a business plan or SOP, humans are unpredictable. We are vulnerable, and there is no getting around hardship and other distracting events that cannot be ignored.

Yet if you could go into a room at work and vent, rant, or just take a time out, an employee can live a moment without judgment and get back on track. When a team feels this kind of support, each member will gain the confidence and mental space to foster and share innovative ideas.

While this idea is unconventional for this industry, Attong points out that unconventional and unusual ideas are a sign of strength in a company. To read more about the “safe space” she suggests, click here.

If you need your cleanroom certified or validated, contact Gerbig Engineering Company. We value the success of your business, and we understand the complexities of these processes. Call 888-628-0056 or email to talk to an expert today.

5 Phases to Cleanroom Validation

Know what goes into the cleanroom validation process so you can best prepare and successfully validate and certify your facility.

Why Validate Your Cleanroom?

Cleanroom control hinges on a number of complex factors. New cleanrooms are validated for a variety of reasons, including:

    • Ensure the facility’s design is fit for its intended purpose
    • Ensure the facility, equipment, and environment meet User Requirement Specifications (URS)
    • Ensure the facility, equipment, and environment meet defined regulatory requirements
    • Ensure the facility, equipment, and environment function together as a system to meet standards

Validation is accomplished through five phases.

1. Design Qualification (DQ).

This phase focuses on the first bullet point above, proving the fit through objective evidence. It focuses on URS, vendor documents and specifications, facility layout, POs, design documentation, factory acceptance tests, as build drawings, and datasheets.

The output involves a phase report and Standard Documentation List (SDL) file documenting the following:

    • Design & bidding requirements
    • Purchasing and order documentation
    • Vendor supplied documents list
    • As build drawings
    • Components list
    • Inspection lists & factory acceptance tests

*Approval of the DQ phase is a pre-requisite for moving on to the next phase.

2. Installation Qualification (IQ).

This phase verifies that the equipment as installed meets user and design requirements. The following are included: HVAC calibration, P&ID loop verification, HEPA filter integrity test data review, critical equipment calibration status, Site Acceptance Tests, Installation Qualification tests, piping and welding documentation, utility verification, and system SOP and work instructions.

The SDL file will address:

    • Project changes
    • IQ tests performed
    • Calibration
    • Supplier supplied documents
    • Equipment certificate(s)
    • Installation deviations
    • Site Acceptance Tests
    • Consumable list
    • Spare part list
    • Environmental review report
    • List of Operational and Instructional documents

*Approval of the IQ phase is a pre-requisite for moving on to the next phase.

3.  Operation Qualification.

This phase proves the cleanroom operates in conformance with both design and user-defined requirements. It also shows that the cleanroom consistently operates within a defined range of conditions. Protocol will address:

    • Testing the HVAC
    • Critical alarms
    • Interlock alarms
    • Critical operating parameters (defined on the room datasheet)
    • Filter integrity tests
    • Standard operation
    • Air speed/flow
    • Air flow patterns
    • Pressure differential

The other piece to this phase is to address worst-case scenarios. Worst cases are designed using operation ranges and extreme ranges from the critical operating parameters on the cleanroom datasheet. It will include maximum and minimum temperatures, maximum and minimum humidity, maintenance schedules, and personnel contamination.

The output is a report addressing alarms and functional requirements of the cleanroom as specified in the user requirement specifications.

4.  Performance Qualification.

This demonstrates that the cleanroom consistently operates within defined parameters to produce the defined/desired environmental outcome. Testing and monitoring includes:

    • Airborne particulate levels
    • Surface particulate levels
    • Viable microbial particulates
    • Relative humidity
    • Differential pressure
    • Temperature

The output report analyzes the performance of the cleanroom against specified equipment parameters. This is a pre-requisite for certification.

At this point, a validated cleanroom is certified. Following successful certification, we move to the final phase.

5.  Monitor & Control.

After certification is complete, you need a constant monitoring program.


If you need your cleanroom validated or certified, or if you have questions about either, contact Gerbig Cleanrooms. We have been in the cleanroom business for 30 years. Call us at 888-628-0056 or email

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