Overview: Dry Hydrogen Peroxide (DHP) technology has been employed in hospitals to reduce surface pathogen contamination risk and improve surface sanitation since at least 2014. The technology uses a proprietary process to generate hydrogen peroxide molecules in the air at low concentrations from a UV-A lamp and a catalyst material, similar to a photocatalytic oxidizer (PCO). Unlike PCO devices, DHP uses a proprietary process to generate hydrogen peroxide instead of a mix of hydrogen and hydroxyl ions and releases them in the air instead of containing them on a catalyst-coated filter. High-concentration liquid hydrogen peroxide has also been used in some schools, distributed as a vapor from a backpack sprayer system, but can’t be used in occupied spaces, and is not considered here as a potential air purification application.

Removes, Dilutes, or Inactivates Pollutants: DHP has not been studied or noted to impact particulates or VOCs, and has inconclusive impacts on airborne pathogens. DHP systems are designed to provide continuous pathogen inactivation on surfaces in spaces supporting regular manual cleaning activities. An August 2020 study published in the American Journal of Infection Control showed surface pathogen reductions of 11.77% at a DHP concentration of 5-25 parts per billion (ppb) of DHP that also allowed occupancy during treatment. A March 2021 study found a 92% reduction in surface contaminants from continuous DHP application along-side manual cleaning. A July 2021 study focused specifically on COVID reduction using DHP and found that 120 minutes of COVID exposure to DHP reduced the infectivity of SARS-CoV-2 by 98.7%, although there was little impact on infectivity before that 120-minute mark.

Harmful Byproducts: The hydrogen peroxide produced by the DHP system is not hazardous on its own as concentrations produced are below the OSHA safe exposure limit of 1 part per million (ppm). However, the main concern with DHP is the partial reaction with airborne VOCs, which can potentially create harmful byproducts like formaldehyde, nitrogen dioxide, and carbon monoxide. The use of DHP as an air cleaner has not yet been thoroughly studied and is not recommended for use as an air cleaning technology at this time. Use of DHP to support manual cleaning of surfaces also bears the same airborne chemical reactions, and thus is not recommended at this time until research can show safe operation.

Added Energy: DHP devices use a 21W UV-A lamp and small fan to generate and distribute ions. Reports on design room size applications are sparse, but a USO application serves 22,000 sf with 10 units, so an estimate of 1 device for every 2,000 sf seems reasonable. Likely one device per classroom and multiple devices in larger spaces like gyms and auditoriums would achieve design DHP concentrations for microbial reductions.

Install Cost: In-room DHP units cost around $2,500 to $3,000 each. Units designed for air handler applications will also require some labor to install in the unit, though modification of the existing HVAC system shouldn’t be necessary in most cases.

Looking beyond the Pandemic

Indoor air quality professionals recommend using proven technologies such as fresh air ventilation, high-MERV or HEPA filtration, and UVGI to control indoor air quality. While DHP is effective as a supplement for surface cleaning applications, it is not proven or recommended for air cleaning