Sterile Pre-Wetted Wipers: What You Need to Know for Your Cleanroom

Up to this point in this 8-part series, we have addressed several things related to pre-wetted wipers: the convenience and consistency of presaturated wipers, how to unlock the best wiper for your cleanroom, the powerful wetting solution of isopropyl alcohol, important wiping techniques for effective cleaning, and most recently unlocking the most from your pre-wetted wipers packaging.

In this next to last part of the series, we turn to a topic of paramount importance: sterile pre-wetted wipers. Why are they of such importance? Because in sterile suites such as aseptic filling, biologics, and sterile testing labs, uncompromising inflexibility of sterility is critical in these environments.

This section will use aseptic environments as the example where sterile protocols must be maintained since there is no opportunity to sterilize the manufactured product terminally. Thus, the environment must always be kept perfectly sterile – in other words, aseptic. Of course, we can apply these procedures to other sterile suites.

Sterile consumables used in aseptic areas must undergo rigorous manufacturing procedures to provide a Sterility Assurance Level of 10ˉ6, which means that there is a probability that only one consumable out of a sample of one million might be found to be non-sterile. So then, it stands to reason that the sterile pre-wetted wipers must conform to these exact stringent requirements.

To illustrate the utility, convenience, and benefits of these products, let’s examine the various ways in which we use sterile pre-wetted wipers in aseptic environments.

First, when items make their way into the cleanroom – generally via a passthrough – you must wipe down the objects themselves or the packaging containing them with a sterile wiper wetted with 70% IPA, which is sterile. If you aren’t sure of what wiper to use, we recommend trying our Berkshire Sterile SatPax® 1200 70% IPA wipes for this process.

Second, pre-wetted wipers are valuable for wiping down the operator’s gloves before touching critical surfaces in the aseptic area. There are two benefits for doing so:

  • The 70% IPA in the wiper will kill any viable organisms on the operator’s gloves
  • The wiping action removes the dead organisms that otherwise could act as a source of endotoxins. 

It’s also important to note that spraying gloves with a 70% IPA solution may kill the organisms, but the endotoxins remain. Endotoxins, the dead cells of the organisms, are of great concern in the medical device industry since those devices are implanted in the body and can cause fevers.

A further benefit to using sterile pre-wetted wipers for glove wipe downs compared to spraying gloves with 70% IPA is that aerosols from the spray have resulted in causing false particle alarms.

After sanitizing the gloves as described above, you can use the sterile pre-wetted wipers to clean environmental surfaces within the aseptic area before, during, and after the manufacturing process.

Sterility Package

Another benefit to using sterile pre-wetted wipers is their ability to remove surface agar residues resulting from Rodac® contact plates. The purpose of these contacts plates is to determine the microbial load on surfaces. When cultured and read, the Rodac® plates can verify that surfaces are free of viable organisms. However, if not removed by sterile pre-wetted wipers, residual agar residues on the surface can act as a growth medium for opportunistic microbials.

Finally, as mentioned above, a key benefit of using sterile pre-wetted wipers is eliminating squirt bottles in the sterile suite. When you dispense alcohol onto a dry wiper from a squirt bottle, you have less control over the amount of alcohol distributed. And the operator’s gloves prevent tactile feedback, which hinders the indication of the optimum level of dampness. Both factors can contribute to using an excessive amount of alcohol for your contamination control requirements.

In closing, it’s essential to highlight again that sterile pre-wetted wipers incorporate the optimum amount of 70% IPA for contamination control activities. And this is important because by using these sterile pre-wetted wipers, there is less alcohol used in the facility. So, that’s an added benefit. There may also be an opportunity to eliminate squirt bottles and the transfer of bulk solvent, representing savings in solvent costs and charges for volatile organic compound (VOC) emissions. Moreover, sterile pre-wetted wipers eliminate fugitive emissions from squirt bottle dispense nozzles and alcohol transfer operations.

We hope we’ve shared some insight relative to sterile pre-wetted wipers and why you need them in your cleanroom. However, if you’re new to the industry or looking for a refresher on some of the topics covered in this week’s article, here are some helpful links to explore:

At Berkshire, we’re always happy to answer your questions regarding your cleanroom contamination needs, so feel free to reach out to our trained specialists for more information.

We hope you’ll join us next week for our final article of this 8-part series. We’ll close it out by discussing cleaning verification in the cleanroom and look at a few employable methods to verify your cleanroom is indeed clean.