What are the Differences and Similarities Between H2O2 and HOCl for Disinfecting a Cleanroom Surface?

Of all the contamination control activities in a cleanroom, perhaps the most critical are disinfection procedures. That’s because human health depends on the quality and thoroughness of surface disinfection.

Many solutions can be considered for surface disinfection, but hydrogen peroxide (H₂O₂) and hypochlorous acid (HOCI) rate special attention.

Hydrogen Peroxide (H₂O₂)

Hydrogen peroxide is a simple molecule – H₂O₂, with one additional oxygen atom bonded within a water molecule. That extra oxygen atom gives hydrogen peroxide strong oxidizing power, destroying bacteria and other harmful organisms when used as a surface disinfectant. The complex oxidation mechanism is believed to involve disrupting bacterial cell walls and DNA structures. The molecular structure of H₂O₂ also contributes to its most outstanding benefit—low residue. The products of H₂O₂’s oxidative reaction are oxygen and water, making it one of the cleanest disinfectants in terms of the type and amount of residue left behind.

Hydrogen peroxide solutions are inherently unstable and decompose over time, which poses particular challenges for the storage and application of H₂O₂. Therefore, these solutions are packaged in opaque containers to prevent decomposition from ambient light. For cleanroom disinfection, 3% and 6% solutions of hydrogen peroxide (in water) in combination with cleanroom wipers have typically been utilized. Wipers can be wetted directly with a hydrogen peroxide solution in the cleanroom before being applied immediately to hard surfaces. Alternatively, packaged wipers pre-wetted with hydrogen peroxide solution have the advantage of simplifying workflow in the cleanroom. Stabilizers must be added to the solutions to prevent wiping cloths from accelerating the decomposition of the hydrogen peroxide, which could compromise its disinfecting capability, thus introducing a higher amount of residue unfavorable for the cleanroom environments. Berkshire solves this problem with our DuoClean™ Hydrogen Peroxide wipes in a burstable dry-to-wet format. The chemistry is released at the point of use only, and the efficacy is maintained during the entire shift when the 15-wipe pack is used. This innovative product ensures both maximum disinfecting power of H₂O₂ and ease of use.

Hypochlorous Acid (HOCI)

Most people recognize the potent disinfecting power of bleach – a 5.5% solution of sodium hypochlorite (NaOCl) in water, as well as its aggressive corrosivity that may cause damages to various surfaces. Few may know, however, that bleach can be transformed into an equally active but safer species — HOCl, or hypochlorous acid. HOCl rapidly breaks down multiple parts of cells of pathogenic organisms, from lipid membranes to proteins that carry out critical biological functions, and quickly renders them inactive or harmless.

Unlike bleach, however, HOCl is in a pH-neutral or slightly acidic solution, married with a lower concentration of the antimicrobial species, making it much less harsh or corrosive to surface materials. The resulting application versatility and safety of HOCl provide for use in many environments, including cleanroom and controlled environments, general institutional or industrial areas, healthcare, hospitality, and schools. HOCl degrades into small amounts of salt, water, and oxygen; shelf-stable 0.065% hypochlorous acid with no added chemical stabilizers, preservatives, or fragrances also enables low residue and surface compatibility advantages, thereby decreasing the rinsing needs and saving time on residue removal. And with no strong, pungent fume or odor, it minimizes the potential adverse health effects for the operator that can be caused by overuse or overexposure to traditional disinfectants.

Berkshire’s EPA-registered VersHOCI® is a one-step, ready-to-use spray with broad-spectrum efficacy that kills 99.99% of bacteria, fungi, and viruses, including organisms that represent a wide variety of common microbiological contaminants: Pseudomonas aeruginosa, Staphylococcus aureus, Trichophyton interdigitale, Human Adenovirus Type 5, Human Coronavirus, and Rhinovirus Type 37. It is also on the EPA-approved List N for SARS-CoV-2 & variants and list Q – Monkeypox Virus. Pure, safe, and effective, Berkshire’s VersaHOCl is establishing safer standards in disinfectant technology. Contact us today to learn more about Berkshire’s portfolio of products and to discuss how they can inform and improve your cleaning protocol needs.

Exhibit 1 below identifies some fundamental properties of disinfectants. This exhibit shows which properties are associated with Hypochlorous Acid (HOCl), Peroxide (H₂O₂), and Bleach.

The check (√) marks indicate the benefits, whereas the (X) marks indicate the drawbacks.

Exhibit 1