FAA Office of Aerospace Medicine
Civil Aerospace Medical Institute

Report No: DOT/FAA/AM-09/7

Title and Subtitle: Inactivating Influenza Viruses on Surfaces Using Hydrogen Peroxide or Triethylene Glycol at Low Vapor Concentrations

Report Date: April 2009

Authors: Rudnick SN, McDevitt JJ, First MW, Spengler JD

Abstract: Any of the exposed surfaces in airplanes can become contaminated with infectious viruses, such as influenza, and facilitate transmission of disease. In this study, we disinfected surfaces contaminated with influenza viruses. Selection of the specific decontamination agents used in this study was based on three criteria:

1. no harm would be caused to the mechanical components or avionics of the airplane,
2. no potentially harmful residue would be left behind, and
3. the airplane could quickly be returned to service.

We chose two decontamination agents that we believed fulfilled these criteria:

1. hydrogen peroxide (HP) at vapor concentrations in air below 100 ppm and
2. triethylene glycol (TEG) saturated air, which has a TEG vapor concentration of about 2 ppm at 25�C.

For influenza viruses deposited on stainless-steel coupons and exposed for 15 min to 10 to 90 ppm of HP vapor, the number of log reductions of active viruses ranged from 3.6 to 4.7. The number of log reductions, however, was not linear with time; log reduction rate decreased significantly with increasing exposure time. For example, at a HP vapor concentration of 57 ppm, the number of log reductions was 3.2 after 2.5 min but just 4.0 after 10 min.

Even after 60 min, the number of log reductions was only 5.6. At a HP vapor concentration of 10 ppm, the number of log reductions was 2.0 after 2.5 min. This corresponds to 99% inactivation of viruses, a significant reduction for such a low HP vapor concentration. For air saturated with TEG at 25-29�C, the number of log reductions of influenza viruses versus exposure time followed a linear relationship reasonably well. The decontamination rate was equal to 1.3 log reductions per hour.

The potential for damage to the mechanical components or avionics of the airplane at a TEG vapor concentration of 2 ppm would be expected to be minimal. In addition, at a 2 ppm TEG vapor concentration, there is essentially no health risks to people.

Key Words: Surface Decontamination, Hydrogen Peroxide Vapor, Vaporized Hydrogen Peroxide, Triethylene Glycol Vapor, Influenza Virus

No. of Pages: 14