Hydrogen Peroxide Biodecontamination—AHP, VPHP, HHP: What is the Difference?

Choosing the Right Hydrogen Peroxide Disinfection Method

In the field of high-level disinfection and biodecontamination, choosing the safest and most effective method is critical to protecting facilities. Hydrogen peroxide has been a trusted, less caustic, and highly effective disinfectant for over a century, used across a range of environments including Biopharma, Biotech, Cell & Gene Therapy, and laboratory research. Today, three primary hydrogen peroxide-based delivery methods are commonly used:

• Hybrid Hydrogen Peroxide™ (HHP™)

• Vapor Phase Hydrogen Peroxide (VPHP)

• Aerosolized Hydrogen Peroxide (AHP)

All are deployed to target high-consequence pathogens, but HHP™ technology stands out for its advanced engineering, consistent efficacy, versatility, and solution chemistry.

How Does Each System Work?

Aerosolized Hydrogen Peroxide (AHP)

AHP systems atomize hydrogen peroxide into a fine mist using pressure and nozzles, producing droplets typically between 5–30 µm in size. These larger droplets may wet surfaces and use peroxide concentrations of 5-10%. While AHP systems range in complexity, many lack precise controls for particle size or disinfectant output, making treatment cycles difficult to measure and replicate. Moreover, peer-reviewed data demonstrating consistent sporicidal efficacy—especially under tri-part soil load conditions—is limited.

 

Vapor Phase Hydrogen Peroxide (VPHP)

Most VPHP (often referred to as vaporized hydrogen peroxide: VHP) systems rely on high-concentration hydrogen peroxide—typically 35–59%—combined with heat to generate vapor particles roughly 0.1–0.5 µm in size. While effective, this narrow particle range can lead to uneven distribution and the formation of microclimates, especially in larger or temperature-variable spaces. The added heat can also drive phase changes that cause surface condensation at concentrations significantly higher than the starting solution, increasing the risk of material degradation (Hultman et al.). Due to the use of high-consequence chemistry, these systems require extensive safety precautions to prevent accidental exposure.

 

Hybrid Hydrogen Peroxide (HHP™)

HHP™ combines vapor and micro-aerosols to enhance distribution and efficacy. CURIS’ patented Pulse™ technology ensures consistent dwell time by replenishing peroxide throughout the treatment cycle. Operating at just 7% hydrogen peroxide, HHP™ systems produce a fine blend of particle sizes to reach all exposed surfaces while maintaining a dry application. The result: validated, repeatable 6-log sporicidal efficacy (even through a tri-part soil load) with better material compatibility and fewer safety concerns compared to other systems.

Does Solution Chemistry Matter?

AHP Chemistry

While AHP often uses lower hydrogen peroxide concentrations (5–10%), it frequently includes secondary ingredients like peracetic acid (a caustic chemical) or silver (a biostat). These additives can raise concerns about staff safety, material compatibility, and residue interference with sensitive research or products. 

 

VPHP Chemistry 

High-concentration hydrogen peroxide (35–59%) used in VPHP systems is classified as hazardous, requiring special handling and shipping. Exposure risks include second-degree chemical burns (CDC) and material degradation, including paint bubbling or stainless steel corrosion (Hultman et al.). Vapor cycles may reach up to 1400 ppm, which can lengthen aeration times and increase safety risks.

 

HHP™ Chemistry 

CURIS’ HHP™ systems use a 7% hydrogen peroxide solution, EPA-registered as a sporicide, with no added caustics or metals. It decomposes into water and oxygen, leaving no harmful residues. With lower peak concentrations (~150 ppm), HHP™ minimizes health and material risks, offering superior material compatibility over higher concentrations, especially on stainless steels, paint, and rubbers. Despite the lower concentration, CURIS HHP™ decontamination achieves rapid, validated 6-log sporicidal kills—often completing full cycles in 30 minutes—without compromising safety or effectiveness. Added bonus: since the solution is only 7%, there are no special requirements or added costs in shipping.

Can These Systems Achieve Sporicidal Efficacy? 

AHP Limitations 

While some private studies exist, federal approval backing AHP sporicidal efficacy to the latest (tri-part soil) standards has not been documented. (Also, some companies only have efficacy data for specific models—buyer beware.)

 

VPHP Effectiveness

VPHP systems are known to achieve sporicidal efficacy and are often validated using biological indicators. However, their complexity, corrosiveness, and safety concerns pose operational challenges.  

 

HHP™ Comprehensive Efficacy

CURIS’ HHP™ technology delivers validated 6-log sporicidal efficacy using biological indicators like Geobacillus stearothermophilus and demonstrates effectiveness even against non-enveloped viruses (up to 10-log reduction). It is federally approved for sporicidal efficacy, including against resilient organisms like C. diff in tri-part soil load conditions. HHP™ offers superior efficacy without the downsides of high-concentration systems or uncertain AHP results.

Final Thoughts on How HHP™ Stacks Up Against AHP and VPHP 

While AHP may be suitable for non-critical spaces, its inconsistent sporicidal performance limits its use in environments demanding validated outcomes.

VPHP has long been favored in life sciences under a “more is better” approach. But as awareness of its operational challenges and material risks has grown, the market has shifted.

HHP™ technology by CURIS System stands out as a safer*, easier-to-use, and more effective solution. Its portability, consistent performance, and material-friendly chemistry make it ideal for life science facilities seeking compliance, protection, and peace of mind.

Expanding Options: Introducing Rapid Vapor™ Technology

While HHP™ remains the cornerstone of CURIS System’s whole-space sporicidal biodecontamination, our new Rapid Vapor™ technology offers the same validated >6-log efficacy in a vapor-only format—without heat or added chemicals. Designed for targeted applications such as isolators, pass-throughs, and small enclosures, Rapid Vapor™ provides fast, dry, repeatable high-level disinfection where speed and precision are paramount.

To learn more about how HHP™ and Rapid Vapor™ systems can support your contamination control goals, talk with one of our SMEs.

 

Comparative Summary: Hydrogen Peroxide-Based Disinfection System

Disinfection System	Organism Tested	Log-Reduction	Application	Pulse Injection
AHP	Bacterial Spore	4-6log	Wet	None
VPHP	Bacterial Spore	6-log	Dry	None
HHP™ / Rapid Vapor™ (CURIS)	Bacterial Spore	6-log	Dry	Yes

*than 35-59% H2O2

Sources

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Knobling, B., Franke, G., Klupp, E. M., Belmar Campos, C., & Knobloch, J. K. (2021).             Evaluation of the Effectiveness of Two Automated Room Decontamination     Devices Under Real-Life Conditions. Frontiers in public health, 9, 618263.    https://doi.org/10.3389/fpubh.2021.618263

Hydrogen peroxide 50%. RXCHEMICALS. (2015). Retrieved September 7, 2022, from http://rxchemicals.com/product/hydrogen-peroxide-50

Centers for Disease Control and Prevention. (2014, October 21). Hydrogen peroxide. Centers for Disease Control and Prevention. Retrieved September 7, 2022, from https://wwwn.cdc.gov/TSP/MMG/MMGDetails.aspx?mmgid=304&toxid=55

Hultman, Carl, (Jan/Feb 2007).  Physical Chemistry of Decontamination with Gaseous Hydrogen Peroxide.  Pharmaceutical Engineering, 22-24. 

https://www.jstage.jst.go.jp/article/jcorr/72/9/72_234/_article/-char/ja/

updated 1/5/2026