Field Evaluation of Whole Airliner Decontamination Technologies – Wide-Body Aircraft With Dual-Use Application for RailcarsWilliam F. GaleHyacinth S. GaleAir Transportation Center of Excellence for Airliner Cabin Environment ResearchAuburn University, AL 36849

Jean WatsonOffice of Aerospace MedicineFederal Aviation AdministrationWashington, DC 20591

February 2008

Final Report

DOT/FAA/AM-08/4Office of Aerospace MedicineWashington, DC 20591

OK-08-1517

NOTICE

This document is disseminated under the sponsorship of the U.S. Department of Transportation in the interest

of information exchange. The United States Government assumes no liability for the contents thereof.

___________

This publication and all Office of Aerospace Medicine technical reports are available in full-text from the Civil Aerospace Medical Institute’s publications Web site:

www.faa.gov/library/reports/medical/oamtechreports/index.cfm

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Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient's Catalog No.

DOT/FAA/AM-08/4 4. Title and Subtitle 5. Report Date

February 2008 Field Evaluation of Whole Airliner Decontamination Technologies – Wide-Body Aircraft With Dual-Use Application for Railcars 6. Performing Organization Code

7. Author(s) 8. Performing Organization Report No. Gale WF, Gale HS, Watson J

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) FAA Civil Aerospace Medical Institute P.O. Box 25082 11. Contract or Grant No. Oklahoma City, OK 73125

12. Sponsoring Agency name and Address 13. Type of Report and Period Covered

Air Transportation Center of Excellence for Airliner Cabin Environment Research Auburn University, AL 36849

Federal Aviation Administration Office of Aerospace Medicine 800 Independence Ave., S.W. Washington, DC 20591 14. Sponsoring Agency Code

15. Supplemental Notes Work was accomplished under Public Law 108-76 16. Abstract The outcome of a field evaluation of decontamination of a wide-body aircraft using AeroClave’s thermal decontamination system both as a stand-alone technology and as a means of delivering STERIS vaporized hydrogen peroxide (VHP®)* is discussed. The report is submitted in the context of a decontamination technology selection exercise, laboratory work conducted on the efficacy of thermal decontamination, and as a follow-on to a field evaluation performed previously on a McDonnell Douglas DC–9 aircraft. The thermal decontamination system appears to be capable of reproducing temperatures needed for an efficacious antiviral process. However, work will be required to improve the temperature control and humidity levels attainable. The thermal decontamination + VHP add-in combination was found to be sporicidal at numerous locations within the cabin. The impact of issues relating to the failure to deactivate Biological Indicators (BIs) in certain locations with limited peroxide penetration, condensation of peroxide within the cabin, and more generally, issues related to the presence of residual peroxide in the cabin after aeration need to be addressed. Serious weather-related disruptions and a limited budget, coupled with a tight schedule, precluded these concerns being addressed on this occasion. Overall, the field evaluation of both the stand-alone thermal decontamination system and the VHP add-in can be described as successful.

*VHP is a registered trademark of the STERIS Corporation, Mentor, OH.

17. Key Words 18. Distribution Statement

Thermal Decontamination, Vaporized Hydrogen Peroxide, Efficacy, Process Control, Technology Evaluation

Document is available to the public through the Defense Technical Information Center, Ft. Belvior, VA 22060; and the National Technical Information Service, Springfield, VA 22161

19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified 15

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized

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ACKNOWLEDGMENTS

The authors thank Dr. Ronald Brown and Messrs Paul Gray and Steven Rohlfing, of AeroClave LLC, and Dr. James Thomas, of STERIS Corporat�on, for the�r help �n mount�ng the demonstra-t�on �n Oklahoma C�ty. To ensure object�v�ty, STERIS and AeroClave took no part �n the evalu-at�on of the demonstrat�on.

The authors also express the�r thanks to Dr. V�p�n Rastog� and Ms. Lalena Wallace, of the U.S. Army Edgewood Chem�cal B�olog�cal Center for v�s�t�ng the demonstrat�on s�te and for helpful d�scuss�ons on the evaluat�on methodology employed.

The ass�stance of personnel at the C�v�l Aerospace Med�cal Inst�tute, �n part�cular Messrs Kenneth Larcher and Dav�d Ruppel for the�r �nvaluable ass�stance w�th us�ng the 747 A�rcraft Env�ronmental Research Fac�l�ty, �s acknowledged w�th thanks.

The work descr�bed �n th�s report was funded by the FAA’s Office of Aerospace Med�c�ne, as part of the A�r Transportat�on Center of Excellence for A�rl�ner Cab�n Env�ronment Research. Although the FAA has sponsored th�s project, �t ne�ther endorses nor rejects the find�ngs of th�s research. The presentat�on of th�s �nformat�on �s �n the �nterest of �nvok�ng techn�cal commun�ty comment on the results and conclus�ons of the research.

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ABBREVIATIONS

As used �n th�s report, the follow�ng abbrev�at�ons/acronyms have the meanings indicated:

AbbreviAtion MeAning

AERF . . .. . .. . .. .A�rcraft Env�ronmental Research Fac�l�ty

APU .. . .. . .. . .. .Aux�l�ary power un�t

BIs . . .. . .. . .. . .. .B�olog�cal �nd�cators

CAMI . .. . .. . .. .C�v�l Aerospace Med�cal Inst�tute

ECBC . .. . .. . .. .Edgewood Chem�cal B�olog�cal Center

ECS .. . .. . .. . .. .Env�ronmental control system

OSHA . .. . .. . .. .Occupat�onal Safety and Health Adm�n�strat�on

PCA .. . .. . .. . .. .Precond�t�oned a�r

PEL. .. . .. . .. . .. .Perm�ss�ble exposure level

RH . .. . .. . .. . .. .Relat�ve hum�d�ty

TSI . .. . .. . .. . .. .Transportat�on Safety Inst�tute

TWA.. . .. . .. . .. .T�me we�ghted average

VHP .. . .. . .. . .. .Vapor�zed hydrogen perox�de

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CONTENTS

INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

METHOD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Object�ves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

747 – Stand-Alone Thermal Decontam�nat�on System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3747 – VHP Add-In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Ra�lcar – Thermal and VHP Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

747 – Stand-Alone Thermal Decontam�nat�on System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3747 – VHP Add-In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8Ra�lcar – Thermal and VHP Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

CONCLUSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

REFERENCES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

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Field evaluation oF Whole airliner decontamination technologies – Wide-Body aircraFt With

dual-use application For railcars

INTRODUCTION

Th�s report descr�bes a follow-on from an earl�er evalu-at�on of a thermal decontam�nat�on system, wh�ch was used both as a stand-alone technology and as a means of del�ver�ng vapor�zed hydrogen perox�de (VHP) �n a narrow-body a�rcraft. Whereas the earl�er report (Gale, 2007) focused on a field evaluat�on us�ng a narrow-body, s�ngle-a�sle, a�rcraft, the present report cons�ders the appl�cat�on of the same technology to a w�de-body, tw�n-a�sle a�rcraft. Th�s work employed the FAA’s A�rcraft Env�ronmental Research Fac�l�ty (AERF), a grounded Boe-�ng 747 a�rcraft located at the C�v�l Aeromed�cal Inst�tute �n Oklahoma C�ty, OK. An attempt was also made to apply the same technolog�es to a two-decker commuter ra�l car belong�ng to the Transportat�on Safety Inst�tute and co-located w�th the 747.

METHOD

Objectives747 – Stand-Alone Thermal Decontamination SystemThe a�m was to demonstrate the ab�l�ty of the system

to heat the ent�re cab�n to a temperature of 60ºC, under cond�t�ons of controlled relat�ve hum�d�ty (RH), w�th-out s�gn�ficantly over-shoot�ng th�s temperature at any locat�on, hold the ent�re cab�n �sothermal at 60ºC for an arb�trary t�me w�thout s�gn�ficant temperature fluctua-t�ons, and to cool back to room temperature rap�dly, but �n a controlled fash�on.

747 – VHP Add-inIn this instance, the goal was to demonstrate the

feasibility of using the stand-alone thermal decontamina-tion system as a means of delivering VHP in an efficient fashion, without requiring bulky vaporizers or other heavy equipment within the cabin, and that the system is capable of delivering controlled quantities of VHP, such that sporicidal conditions can be achieved throughout the cabin. As such, the VHP tests were not intended to be definitive but to explore initial viability and establish parameters for more detailed tests in the future.

It �s to be stressed that, unl�ke earl�er work on a smaller McDonnell Douglas DC-9 a�rcraft for wh�ch there was extens�ve pr�or setup, the work on the 747 was relat�vely exploratory. Furthermore, �n the case of the ra�lcar, th�s

was no more than an �n�t�al demonstrat�on of capab�l-�ty, not a formally evaluated test of decontam�nat�on performance.

Railcar – Thermal and VHP RunsA s�ngle decontam�nat�on un�t was employed to dem-

onstrate both thermal and VHP decontam�nat�on.

MethodologyThe thermal decontam�nat�on system, as a stand- alone

technology, was deployed �n �ts standard configurat�on. Deta�ls of th�s may be found �n the outcomes of the de-contam�nat�on technology down select (Gale et al., 2006) and �n an earl�er report on work on narrow-body a�rcraft (Gale, 2007). In summary, the thermal decontam�nat�on system �s des�gned to del�ver heated or cooled a�r, under feed-back control from a self conta�ned un�t housed on a sem�-tra�ler. G�ven the relat�vely large volume of the 747’s �nter�or, two such un�ts were employed, both of wh�ch were controlled from a stat�on set up adjacent to the a�rcraft. The un�ts were connected to the cab�n v�a flex�ble a�r del�very and return hoses. Custom door plugs connected to the �nlet and outlet hoses were fabr�cated on-s�te. In th�s configurat�on, the a�r �nlets were at the emergency ex�t doors above the w�ng and the a�r outlets at the front and rear cab�n doors. A�r suppl�es and re-turns were located on both the port and starboard s�des of the a�rcraft.

It �s �mportant to note that the 747 a�rcraft used �n the evaluat�on d�d not reta�n the or�g�nal configurat�on of the env�ronmental control system (ECS). Hence, only the cab�n �nter�or and not the cargo bay or ECS ducts were decontam�nated. The AERF �s equ�pped for evacuat�on research and hence has a smoke el�m�nat�on system. Th�s was capped off before start�ng the present work, and so the cab�n geometry �s reasonably s�m�lar to that of an operat�onal 747. The cab�n of the AERF was equ�pped w�th almost a complete set of seats. Dummy plywood fixtures w�th a st�ck-on plast�c coat�ng are used by CAMI �n place of the lavator�es and galleys.

The thermal decontam�nat�on system �n �ts or�g�nal configurat�on d�d not �nclude a hum�d�ficat�on capab�l-�ty. Hence, on heat�ng, the relat�ve hum�d�ty �n the cab�n dropped qu�ckly. Based on the results of an earl�er study (Rudn�ck et al., 2006), wh�ch �nd�cated a need to ma�nta�n a RH of > 35% at 60ºC, the equ�pment manufacturer

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opted to add a 100 kW steam-based hum�d�ficat�on sys-tem, wh�ch was employed dur�ng the evaluat�on descr�bed �n th�s report. The output from the steam generator was fed �nto the first of the two sem�-tra�lers used to decon-tam�nate the 747.

In the case of the VHP add-�n, a deta�led descr�pt�on of the setup employed may be found elsewhere (Thomas, 2007), and hence only the key po�nts are d�scussed here. VHP was �njected �nto the a�r del�very system from an external bank of two VHP generators located �n the second tra�ler.

It �s �mportant to note that the �ntended funct�on of the thermal decontam�nat�on system changes depend�ng on wh�ch mode th�s �s employed �n.

In the stand-alone configurat�on, the thermal de-contam�nat�on system �s �ntended to del�ver hot a�r of controlled hum�d�ty to ach�eve thermal decontam�nat�on to el�m�nate v�ruses and then cool the a�rcraft back to a des�red temperature and relat�ve hum�d�ty so that people may re-enter the cab�n. The thermal decontam�nat�on system may also have other appl�cat�ons, such as non-chem�cal d�s�nsect�on, as was d�scussed �n the technology evaluat�on (Gale et al., 2006).

The thermal decontam�nat�on system, when used �n conjunct�on w�th the VHP add-�n, produces env�ronmen-tal precond�t�on�ng pr�or to the �nject�on of VHP. Th�s �nvolves reduc�ng the RH to below 60% (�deally 50% or lower), del�very of VHP to the cab�n, and aerat�on to extract VHP from the cab�n.

Railcar – Thermal and VHP RunAlthough the pr�mary focus of the work reported

here was on w�de-body a�rcraft, the opportun�ty was taken to demonstrate decontam�nat�on of a two-decker commuter ra�lcar. In th�s case, a s�ngle decontam�nat�on un�t was employed to demonstrate both thermal and VHP decontam�nat�on. The �nlet and outlet hoses were placed �n the end doors of the ra�lcar, us�ng door plugs manufactured on s�te.

ProtocolsThe follow�ng protocols were establ�shed �n advance

of the test�ng. As was noted above, work on the 747 was exploratory and so the a�m was s�mply to approach these cond�t�ons as closely as poss�ble, rather than a “pass/fa�l” scenar�o for the technology.

747 – Stand-Alone Thermal Decontamination SystemThe cab�n of the 747 would be �nstrumented w�th

relat�ve hum�d�ty sensors (one �n the front and one at the rear of the cab�n) and 36 thermocouples, and data were logged cont�nuously.

At least three sets of data were to be collected, one of wh�ch would be on the day of the Edgewood Chem�cal B�olog�cal Center (ECBC) evaluat�on and meet�ng the follow�ng cr�ter�a. The target cab�n surface would be ma�n-ta�ned at 60ºC for at least two hours. The temperature at the a�r �nlet would not exceed 65ºC, and the target relat�ve hum�d�ty would be 50%. The cargo area would be excluded from the evaluat�on.

747 – VHP Add-inThe cab�n would be equ�pped w�th the same �nstrumen-

tat�on used for the stand-alone thermal decontam�nat�on system. Add�t�onally, s�x ATI hydrogen perox�de vapor sensors for measur�ng the work�ng concentrat�on of the VHP would be �ncluded.

Th�rty Apex 6 log G. Stearothermoph�lus b�olog�cal �nd�cators (BIs) would be placed throughout the cab�n. Note: In the field work, chem�cal �nd�cators (CIs) were co-located w�th the BIs so as to supplement the perox�de sen-sors, although th�s was not spec�fied �n the protocol.

Per�pheral sensors would be placed around the a�rcraft, �nclud�ng near the outlet used to flush the VHP, to dem-onstrate compl�ance w�th OSHA PEL and other relevant exposure l�m�ts. Handheld sensor(s) w�th manual data record�ng would be used �n l�eu of su�tably cal�brated automated sensors, not ava�lable on-s�te. VHP concen-trat�ons would be mon�tored on enter�ng the cab�n after each run us�ng su�table �nstrumentat�on.

A m�n�mum of three runs would be performed, �n-clud�ng one on the day of the formal evaluat�on, w�th observers from the FAA and ECBC present.

All of the runs would be performed under the follow-�ng cond�t�ons: VHP concentrat�on would be ma�nta�ned between 125 – 200 ppm for at least two hours at all lo-cat�ons sampled. The VHP concentrat�on would not be allowed to exceed 500 ppm at any locat�on to m�n�m�ze the r�sk of condensat�on.

VHP concentrat�ons would be mon�tored on enter�ng the cab�n after each run to ensure that the read�ng d�d not exceed 1 ppm for those runs �n wh�ch aerat�on was allowed to run to complet�on.

In v�ew of t�me constra�nts, the run dur�ng the ECBC (Rastog�, 2007) and FAA v�s�t would be term�nated at 2 – 5 ppm, wh�le ensur�ng that the durat�on of exposure for personnel harvest�ng the BIs was carefully mon�tored so that no �nd�v�dual’s exposure would exceed the OSHA 1 ppm TWA PEL. In the case of all runs, except that carr�ed out on the day of the evaluat�on, the mon�tor�ng descr�bed �n the prev�ous paragraph would be repeated to detect any VHP out-gass�ng from porous med�a w�th�n the cab�n. Add�t�onal aerat�on would be employed as found necessary, and the measurements would be repeated.

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Railcar – Thermal and VHP RunThe mon�tor�ng procedures for both the thermal and

VHP decontam�nat�on runs would be s�m�lar to those employed for the 747 but w�th a reduced number of sensors. Th�s would not be a formal evaluat�on, as has already been noted, but would be an �n�t�al demonstra-t�on of capab�l�ty.

RESULTS

747 – Stand-Alone Thermal Decontamination System

It proved poss�ble to heat the major�ty of the 747 cab�n to close to 60ºC and hold fa�rly near to th�s temperature for an extended per�od w�th the use of two thermal de-contam�nat�on un�ts (F�gure 1). However, �n some cases reg�ons, �t was not poss�ble to hold at 60ºC for 2 hours, as st�pulated �n the protocol (F�gure 2). Surface temperatures �n other locat�ons (e.g. adjacent to the �nlet) were found to exceed 65ºC, w�th a max�mum temperature of 71ºC be�ng observed where the �ncom�ng a�r stream �mp�nged on the cab�n (F�gure 3). The two thermal decontam�nat�on un�ts appeared to be well matched to the thermal mass of the 747, whereas a s�ngle un�t had a rather larger heat�ng capab�l�ty than that requ�red for a DC-9.

An effort was made to sample the temperature at locat�ons throughout the cab�n, encompass�ng surfaces compr�sed of a w�de range of mater�als and thermal masses. All temperatures spec�fied are surface temperatures, not a�r temperatures. Some run-to-run scatter was apparent for runs conducted w�th �dent�cal control parameters.

Us�ng the 100 kW steam generator, �t was not found poss�ble to br�ng the cab�n RH to above 20% (F�gures 4 and 5).

747 – VHP Add-InThe comb�ned system appeared to be capable of

controll�ng the VHP concentrat�on �n the 747’s cab�n, based on the output from 8 hydrogen perox�de sensors (Thomas, 2007). It was poss�ble to ma�nta�n an average cab�n hydrogen perox�de concentrat�on of around 175 ppm under non-condens�ng cond�t�ons, wh�ch should be suffic�ent to produce a spor�c�dal act�on (concentrat�ons above ~ 80 ppm are usually cons�dered spor�c�dal). The hydrogen perox�de concentrat�on measured adjacent to the �nlet d�d not exceed 275 ppm, and hence there does not appear to be a r�sk of macroscop�c condensat�on of the perox�de (and local�zed condensat�on would requ�re pockets of h�gh hum�d�ty). However, some condensed perox�de was apparent �n the return a�r cab�net of the thermal decontam�nat�on system’s a�r handler and at weather-�nduced breaches to the temporary wooden door plugs.

In a few cases, the 6 log G. Stearothermoph�lus b�olog�-cal �nd�cators (BIs) placed throughout the cab�n d�d not ach�eve complete k�ll. These BIs were placed �n locat�ons where perox�de access proved d�fficult to ach�eve (see Gale, 2007 for a note on the l�m�tat�ons of the label cla�ms made by STERIS w�th respect to occluded spaces). The only cases of extens�ve k�ll fa�lures �n large port�ons of the cab�n were due to weather-generated equ�pment fa�lures that caused condensat�on of the perox�de (Thomas, 2007). Table 1 sum-mar�zes the data obta�ned from the BIs. As �n earl�er work on the DC-9, some �ssues were encountered w�th release of perox�de trapped �n seat fabr�cs, etc. Opt�m�zat�on of the aerat�on cycle seemed to help s�gn�ficantly �n address�ng th�s problem, although th�s st�ll rema�ns an �ssue. Th�s work �s descr�bed �n deta�l �n another report (see Thomas, 2007).

Railcar – Thermal and VHP RunAlthough not formally evaluated, �n�t�al work on the

ra�lcar �nd�cated that �t �s poss�ble to reach the targeted env�ronmental cond�t�ons for both thermal and VHP de-contam�nat�on. The absence of absorbent surfaces w�th�n the ra�lcar made the removal of VHP dur�ng post-decon-tam�nat�on aerat�on much less challeng�ng than was the case for the 747. A two-hour exposure at an average 250 ppm VHP concentrat�on deact�vated all BIs placed �n the ra�l car. Table 2 shows the k�ll results from the BIs.

DISCUSSION

747 – Stand-Alone Thermal Decontamination System

As already noted, the pr�mary focus of the work re-ported was on determ�n�ng the feas�b�l�ty of scal�ng up of decontam�nat�on from the earl�er work on the DC-9 to the 747, rather than on opt�m�zat�on of the decontam�nat�on process �tself. Hence, the �ssues that were not addressed �n the DC-9 work rema�n (Gale, 2007). In the �nterests of brev�ty, they w�ll not be repeated here.

Notw�thstand�ng the mod�ficat�ons made to the 747, the work performed on the AERF can be regarded as a reasonable analogue for decontam�nat�on of an actual a�rl�ner cab�n (m�nus the cargo area and ECS ducts) �n that the thermal mass should st�ll be fa�rly s�m�lar to an actual w�de-body a�rcraft, and most of the or�g�nal mater�als of construct�on rema�ned �n place.

Most of the cab�n was effic�ently heated, w�thout resort to an a�r d�str�but�on system w�th�n the cab�n. However, one locat�on, adjacent to one of the cab�n serv�ce areas (galleys and lavator�es), was found to have �nsuffic�ent a�rflow, so an extens�on trunk was used to del�ver a�r to th�s locat�on (Thomas, 2007). It �s poss�ble that, w�th further opt�m�zat�on of the a�r del�very system, the exten-s�on trunk could be el�m�nated.

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Table 1. Biological Indicator Results for 747 (Provided by Jim Thomas, STERIS Corporation)

Record Run 1 Record Run 2 Record Run 3

BI Location 48 hr 7 day 48 hr 7 day 48 hr 7 day

1 - - - - + + 2 - - - - - - 3 - - - - - - 4 - - - - - - 5 + + - - - - 6 - - - - - - 7 - - - - - - 8 - - - - - - 9 - - - - - - 10 - - - - - + 11 - - - - + + 12 + + - - - - 13 - - - - + + 14 - - - - - - 15 - - - - + + 16 - - - - + + 17 - - - - + + 18 - - - - - - 19 - - - - + + 20 + + - - + + 21 - - - - + + 22 - - - - - - 23 - - - - - - 24 - - - - - - 25 - - - - + + 26 - - - - - - 27 - - - - - - 28 - - - - - - 29 - - - - - - 30 - - + + - - + Control + + + + + + + Control + + + + + + + Control + + + + + + + Control + + + + + +

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Table 2. Biological Indicator Results for Rail Car (Provided by Jim Thomas, STERIS Corporation)

BI Location 48 hr 7 day

1 - - 2 - - 3 - - 4 - - + Control + + + Control + + + Control + +

Cab�n temperature on mult�ple cab�n surfaces exceeded the des�red 60ºC. Th�s was due to one of the two un�ts hav�ng to be operated at 65ºC and the second at 85ºC, due to on-s�te power l�m�tat�ons. It must be noted that the present tr�als were conducted on a very t�ght schedule and budget. It �s l�kely that g�ven a longer lead t�me, more prov�ng runs, and add�t�onal resources, the temperature control �ssues can be addressed.

Fa�lure to reach a hum�d�ty of > 30% RH for rap�d ant�v�ral efficacy (Rudn�ck et al., 2006) was d�sappo�nt-�ng. However, th�s does not appear to be a fundamental problem w�th the system but a matter of exceed�ng the capac�ty of the ex�st�ng steam generator to hum�d�fy a w�de-body a�rcraft. Th�s �s an �ssue that can be addressed eas�ly �n the future.

Apart from the above, no s�gn�ficant �ssues were ap-parent that had not already man�fested themselves �n the DC-9 work. Indeed, the results are generally encourag-�ng w�th respect to the feas�b�l�ty of scal�ng up thermal decontam�nat�on to w�de-body a�rcraft.

747 – VHP Add-InAs �n the case of thermal decontam�nat�on, �ssues �dent�-

fied �n the DC-9 work pers�sted w�th the 747. However, progress does seem to have been made w�th respect to �mprov�ng the effic�ency of aerat�on (Thomas, 2007). Nonetheless, �n our op�n�on, th�s �s an �ssue that st�ll needs to be addressed and one w�th scope for further �mprove-ment through opt�m�zat�on of the aerat�on stage.

It was noted �n the ECBC report (Rastog�, 2007) that there was ev�dence, post test, of the presence of res�dual perox�de at a s�gn�ficant, but unquant�fied, concentrat�on. Unfortunately, �t has not yet proved poss�ble, after the fact, to �dent�fy exactly when and where any perox�de hotspot occurred. Dur�ng break-down of the system

after the exper�ments, one of the authors d�d not�ce some res�dual perox�de �n the supply l�nes, but �t �s hard to see how th�s would have been apparent dur�ng the demonstrat�on �tself.

The work conducted on the 747 �s generally encourag-�ng �n that scale-up was ach�eved. However, �ssues related to res�dual perox�de rema�n�ng after aerat�on must be addressed �n any future work.

Railcar – Thermal and VHP RunAlthough not formally evaluated, no problems were

encountered dur�ng the ra�lcar decontam�nat�on dem-onstrat�on, and th�s appears to be a successful �n�t�al demonstrat�on of a capab�l�ty for decontam�nat�ng such veh�cles.

CONCLUSIONS

As a result of the field evaluat�on of the stand-alone thermal decontam�nat�on system and the VHP add-�n, scaled up for appl�cat�on to a w�de-body a�rcraft, the follow�ng conclus�ons have been drawn:

The thermal decontam�nat�on system appears to be capable of reproduc�ng �n the field the temperatures found �n an earl�er study to be needed for an efficac�ous ant�v�ral process (Rudn�ck et al., 2006). Further work w�ll need to be done to �mprove the temperature control to el�m�nate overheat�ng of cab�n surfaces. Reach�ng a relat�ve hum�d�ty > 20% was found to be a problem, but th�s appears to be eas�ly addressable w�th the add�t�on of e�ther a larger capac�ty or second steam generator.

The thermal decontam�nat�on + VHP add-�n comb�-nat�on was found to be spor�c�dal at numerous locat�ons w�th�n the cab�n. The �mpact of �ssues relat�ng to the fa�lure to deact�vate BIs �n certa�n locat�ons w�th l�m�ted perox�de penetrat�on w�ll need to be addressed. Condensat�on of perox�de w�th�n the cab�n w�ll also need to be addressed �n future work on a w�de-body a�rcraft. More generally, �ssues related to the presence of res�dual perox�de �n the cab�n after aerat�on need to be more fully addressed.

Th�s evaluat�on of the 747 was conducted on a very l�m�ted budget and a t�ght schedule. Furthermore, there were weather-related d�srupt�ons that severely �mpeded set up and operat�on of the equ�pment. G�ven more t�me and resources, �t �s env�saged that most of the �ssues of concern can be addressed.

Although th�s was not a formal evaluat�on, the �n�t�al outcome from the ra�lcar decontam�nat�on demonstrat�on appears to be prom�s�ng.

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REFERENCES

Gale, W.F., Prorok, B.C., Gale, H.S., Sofyan, N.I., Bar-baree, J.M.,and Neely, W.C. (2006). Report on the Selection of Decontamination Technologies for Further Evaluation or Implementation, Auburn Un�vers�ty, Auburn, AL.

Gale, W.F. (2007). Report on Field Evaluation of Whole Airliner Decontamination Technologies, Auburn Un�vers�ty, Auburn, AL.

Rastog�, V.K. (2007). Report on ECBC Staff Visit to CAMI (Civil Aerospace Medical Institute), Oklahoma City Airport – Decontamination of a Boeing 747 Air Cabin Interior, US Army – ECBC.

Rudn�ck, S. and Spengler, J. (2006). Report on the Thermal Inactivation of Vaccinia Viruses on Surfaces, Depart-ment of Env�ronmental Health, Harvard School of Publ�c, Boston, MA.

Thomas, J.A. (2007), Decontamination Feasibility Tests on a Boeing 747 Aircraft Passenger Cabin and Com-muter Train Car With STERIS’ Vaporized Hydrogen Peroxide (VHP®) Technology and an AeroClave, LLC High Velocity Air Handling System, STERIS Corporat�on, Mentor, OH.