Using cleanroom wipes for disinfection is common in compounding pharmacies, laboratories, hospitals, medical device manufacturing, food handling, and other sterile processing industries. In addition to using the proper lint-free wipe, you should choose the right method to apply the solution and the optimal wiping method for your disinfection application.
The right cleanroom wipe for your disinfection procedure depends on what you are disinfecting, the type of disinfectant used, and the wiping strategy.
Types of Cleanroom Disinfectants
Most cleanroom disinfection uses one of 3 disinfecting solutions: alcohol, hypochlorite bleach, hydrogen peroxide.
Isopropyl Alcohol
IPA leaves no toxic residue, though its effect on the nervous system make it dangerous to ingest or to inhale. So it is important during extended periods of cleaning to ensure there is proper ventilation and containers are closed after use. Inhaling large amounts of isopropyl alcohol can cause nausea, vomiting, nose and mucous membrane irritation, throat irritation, and excessive coughing can make it difficult to catch your breath.
It can be corrosive to metal, especially when used frequently and in high concentration. See our tips on selecting stainless steel for your cleanroom.
IPA is extremely inflammable. Vapors may form in the air traveling to a source of ignition and flash back. Water spray to fight such fires may be inefficient. In addition to keeping IPA away from heat, sparks, flames, and other ignition sources, also use a flammable safety cabinet to separate it from strong oxidizers, acetaldehyde, chlorine, ethylene oxide, acids, and isocyanates.
Hypochlorite Bleach
Hypochlorite is the most widely used chlorine disinfectant. It is also an economical disinfectant with rapid bactericidal properties. It’s not affected by water hardness and has a wide range of bactericidal spectrum and is sporicidal with no toxic residues.
Care should be given for what applications it is used for as hypochlorite is easily neutralized by organic matter.
Hypo bleach can also be corrosive to metals at higher concentrations. It may also irritate the skin, nose, throat, and eyes which is usually eliminated in the cleanroom setting because of proper PPE. It can produce toxic gas if mixed with certain chemicals including acid and ammonia.
Hydrogen Peroxide
Hydrogen peroxide presents wide-ranging germicidal action including bacterial spores (with longer contact time).
For cleanroom sterilization, a vaporized mixture of hydrogen peroxide and water is common. It is a popular chemical for presaturated cleanroom wipes. It quickly degrades leaving no residues making it relatively environmentally friendly. Its effectiveness remains even when in contact with organic matter.
When diluted, hydrogen peroxide is inconsistent and may be ineffective. It can also be corrosive to metals.
Wiping Methods for Disinfection
Spray Then Wipe Method
Using a trigger spray bottle or aerosol can, the solution is applied directly onto the surface then the surface is wiped to evenly apply across the entire surface.
This is the ideal wiping method for covering large flat areas.
Advantages of direct spraying are direct contact with the surface and control over the amount of solution dispensed. But the reliance on the operator spraying the right amount of solution or preventing over-spray onto other surfaces is problematic.
Areas that are difficult to reach (under a table) or are non-flat (a hand rail) benefit from using a cleanroom sponge to apply the solution for better coverage. Also, when spraying the solution is airborne which produces volatile organic compounds (VOCs) that can be harmful to humans.
Dip Then Wipe Method
The operator dips a dry cleanroom wiper into the solution for 5-10 seconds to saturate the wipe. Excess solution is removed by squeezing it out. This wiping method offers greater control over the amount and location of the solution applied. This method also relies on the user to use the right amount of solution for the wiping process thus disinfection effectiveness as with spraying can be compromised. Another problem is that re-dipping the used wipe promotes cross-contamination.
Soak Then Wipe Method (Bucket Method)
This disinfection wiping method is commonly used in hospitals. The wiper is soaked in the disinfectant solution for usually 10 minutes up to several hours. Then the wipe is wrung out and wiped across the surface. This method with its longer contact time ensures an effective solution saturation in the wipe. However, some studies have identified possible reduced antimicrobial activity due to interactions between wipes and disinfectant when longer soaking times are used. Reuse of the wipe can result in cross-contamination.
Presaturated Wipes
Ready-to-use wipes are pre-saturated with the desired solution. Many common disinfectants are available in presaturated wipes and we offer top quality cleanroom wipes in a pre-saturation-ready pouch so you can make your presaturated wipes with the cleanroom disinfection solution of your choosing.
Presaturated wipes come in resealable tubs, bags, or canisters. The wipes themselves cost a little more than purchasing separate wipes and solutions with applicators such as spray bottles but they are actually quite cost-effective as they:
- eliminate preparation time for your staff
- eliminate cross-contamination as each wipe is dispensed one at a time
- deliver a consistent solution concentration.
It is important to pay attention to the storage time indicated on the package as when stored too long decreased antimicrobial activity is possible. Also, using wipes to dispense the disinfectant may not be as effective or efficient for larger surface areas since the wiping contains a limited amount of solution.
Though not for every application, presaturated wipes are today the most popular wiping method due to its versatile, convenience, and lower probability of disinfection failure.
Proper Cleanroom Wiping Technique
No matter which disinfectant application method you choose, it is vital to use the proper wiping technique to ensure that contaminants are completely removed and the entire surface is disinfected. And, also, key to the wiping process is using cleanroom wipes that support your critical area’s cleanliness levels.
This video demonstrates this proper cleanroom wiping technique.
We offer a wide variety of wiper materials and formats including custom sizes. Let our cleanroom consultants help you decide what is best for your applications by offering free samples before you buy. And we can help ensure that your wipes and disinfectants are compatible with each other and your facility’s SOP.