Office DOT/FAA/AM-08/4 of Aerospace Medicine Washington, DC 20591
Field Evaluation of Whole Airliner Decontamination Technologies Wide-Body Aircraft With Dual-Use Application for Railcars
William F. Gale Hyacinth S. Gale Air Transportation Center of Excellence for Airliner Cabin Environment Research Auburn University, AL 36849 Jean Watson Office of Aerospace Medicine Federal Aviation Administration Washington, DC 20591 February 2008 Final Report
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 Institutes publications Web site:
www.faa.gov/library/reports/medical/oamtechreports/index.cfm
Technical Report Documentation Page
1. Report No.
DOT/FAA/AM-08/4
4. Title and Subtitle
2. Government Accession No.
3. Recipient's Catalog No. 5. Report Date
Field Evaluation of Whole Airliner Decontamination Technologies Wide-Body Aircraft With Dual-Use Application for Railcars
7. Author(s)
February 2008
6. Performing Organization Code 8. Performing Organization Report No.
Gale WF, Gale HS, Watson J
9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) 11. Contract or Grant No.
FAA Civil Aerospace Medical Institute P.O. Box 25082 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
15. Supplemental Notes
Federal Aviation Administration Office of Aerospace Medicine 800 Independence Ave., S.W. Washington, DC 20591
14. Sponsoring Agency Code
Work was accomplished under Public Law 108-76
16. Abstract
The outcome of a field evaluation of decontamination of a wide-body aircraft using AeroClaves 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 DC9 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
Thermal Decontamination, Vaporized Hydrogen Peroxide, Efficacy, Process Control, Technology Evaluation
19. Security Classif. (of this report)
Unclassified
20. Security Classif. (of this page)
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
21. No. of Pages
18. Distribution Statement
Unclassified
15
22. Price
Form DOT F 1700.7 (8-72)
Reproduction of completed page authorized
ACKNOWLEDGMENTS
The authors thank Dr. Ronald Brown and Messrs Paul Gray and Steven Rohlfing, of AeroClave LLC, and Dr. James Thomas, of STERIS Corporaton, for ther help n mountng the demonstraton n Oklahoma Cty. To ensure objectvty, STERIS and AeroClave took no part n the evaluaton of the demonstraton. The authors also express ther thanks to Dr. Vpn Rastog and Ms. Lalena Wallace, of the U.S. Army Edgewood Chemcal Bologcal Center for vstng the demonstraton ste and for helpful dscussons on the evaluaton methodology employed. The assstance of personnel at the Cvl Aerospace Medcal Insttute, n partcular Messrs Kenneth Larcher and Davd Ruppel for ther nvaluable assstance wth usng the 747 Arcraft Envronmental Research Faclty, s acknowledged wth thanks. The work descrbed n ths report was funded by the FAAs Office of Aerospace Medcne, as part of the Ar Transportaton Center of Excellence for Arlner Cabn Envronment Research. Although the FAA has sponsored ths project, t nether endorses nor rejects the findngs of ths research. The presentaton of ths nformaton s n the nterest of nvokng techncal communty comment on the results and conclusons of the research.
ABBREVIATIONS As used n ths report, the followng abbrevatons/acronyms have the meanings indicated: AbbreviAtion MeAning AERF . . .. . .. . .. .Arcraft Envronmental Research Faclty APU .. . .. . .. . .. .Auxlary power unt BIs. . .. . .. . .. . .. .Bologcal ndcators CAMI . .. . .. . .. .Cvl Aerospace Medcal Insttute ECBC . .. . .. . .. .Edgewood Chemcal Bologcal Center ECS .. . .. . .. . .. .Envronmental control system OSHA . .. . .. . .. .Occupatonal Safety and Health Admnstraton PCA .. . .. . .. . .. .Precondtoned ar PEL. .. . .. . .. . .. .Permssble exposure level RH . .. . .. . .. . .. .Relatve humdty TSI . .. . .. . .. . .. .Transportaton Safety Insttute TWA.. . .. . .. . .. .Tme weghted average VHP .. . .. . .. . .. .Vaporzed hydrogen peroxde
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CONTENTS
INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 METHOD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Objectves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Protocols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 747 Stand-Alone Thermal Decontamnaton System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 747 VHP Add-In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Ralcar Thermal and VHP Run . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 DISCUSSION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 747 Stand-Alone Thermal Decontamnaton System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 747 VHP Add-In . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Ralcar 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
Ths report descrbes a follow-on from an earler evaluaton of a thermal decontamnaton system, whch was used both as a stand-alone technology and as a means of delverng vaporzed hydrogen peroxde (VHP) n a narrow-body arcraft. Whereas the earler report (Gale, 2007) focused on a field evaluaton usng a narrowbody, sngle-asle, arcraft, the present report consders the applcaton of the same technology to a wde-body, twn-asle arcraft. Ths work employed the FAAs Arcraft Envronmental Research Faclty (AERF), a grounded Boeng 747 arcraft located at the Cvl Aeromedcal Insttute n Oklahoma Cty, OK. An attempt was also made to apply the same technologes to a two-decker commuter ral car belongng to the Transportaton Safety Insttute and co-located wth the 747. was no more than an ntal demonstraton of capablty, not a formally evaluated test of decontamnaton performance. Railcar Thermal and VHP Runs A sngle decontamnaton unt was employed to demonstrate both thermal and VHP decontamnaton. Methodology The thermal decontamnaton system, as a stand- alone technology, was deployed n ts standard configuraton. Detals of ths may be found n the outcomes of the decontamnaton technology down select (Gale et al., 2006) and n an earler report on work on narrow-body arcraft (Gale, 2007). In summary, the thermal decontamnaton system s desgned to delver heated or cooled ar, under feed-back control from a self contaned unt housed on a sem-traler. Gven the relatvely large volume of the 747s nteror, two such unts were employed, both of whch were controlled from a staton set up adjacent to the arcraft. The unts were connected to the cabn va flexble ar delvery and return hoses. Custom door plugs connected to the nlet and outlet hoses were fabrcated on-ste. In ths configuraton, the ar nlets were at the emergency ext doors above the wng and the ar outlets at the front and rear cabn doors. Ar supples and returns were located on both the port and starboard sdes of the arcraft. It s mportant to note that the 747 arcraft used n the evaluaton dd not retan the orgnal configuraton of the envronmental control system (ECS). Hence, only the cabn nteror and not the cargo bay or ECS ducts were decontamnated. The AERF s equpped for evacuaton research and hence has a smoke elmnaton system. Ths was capped off before startng the present work, and so the cabn geometry s reasonably smlar to that of an operatonal 747. The cabn of the AERF was equpped wth almost a complete set of seats. Dummy plywood fixtures wth a stck-on plastc coatng are used by CAMI n place of the lavatores and galleys. The thermal decontamnaton system n ts orgnal configuraton dd not nclude a humdficaton capablty. Hence, on heatng, the relatve humdty n the cabn dropped quckly. Based on the results of an earler study (Rudnck et al., 2006), whch ndcated a need to mantan a RH of > 35% at 60C, the equpment manufacturer
1
METHOD
Objectives 747 Stand-Alone Thermal Decontamination System The am was to demonstrate the ablty of the system to heat the entre cabn to a temperature of 60C, under condtons of controlled relatve humdty (RH), wthout sgnficantly over-shootng ths temperature at any locaton, hold the entre cabn sothermal at 60C for an arbtrary tme wthout sgnficant temperature fluctuatons, and to cool back to room temperature rapdly, but n a controlled fashon. 747 VHP Add-in In this instance, the goal was to demonstrate the feasibility of using the stand-alone thermal decontamination 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, unlke earler work on a smaller McDonnell Douglas DC-9 arcraft for whch there was extensve pror setup, the work on the 747 was relatvely exploratory. Furthermore, n the case of the ralcar, ths
opted to add a 100 kW steam-based humdficaton system, whch was employed durng the evaluaton descrbed n ths report. The output from the steam generator was fed nto the first of the two sem-tralers used to decontamnate the 747. In the case of the VHP add-n, a detaled descrpton of the setup employed may be found elsewhere (Thomas, 2007), and hence only the key ponts are dscussed here. VHP was njected nto the ar delvery system from an external bank of two VHP generators located n the second traler. It s mportant to note that the ntended functon of the thermal decontamnaton system changes dependng on whch mode ths s employed n. In the stand-alone configuraton, the thermal decontamnaton system s ntended to delver hot ar of controlled humdty to acheve thermal decontamnaton to elmnate vruses and then cool the arcraft back to a desred temperature and relatve humdty so that people may re-enter the cabn. The thermal decontamnaton system may also have other applcatons, such as nonchemcal dsnsecton, as was dscussed n the technology evaluaton (Gale et al., 2006). The thermal decontamnaton system, when used n conjuncton wth the VHP add-n, produces envronmental precondtonng pror to the njecton of VHP. Ths nvolves reducng the RH to below 60% (deally 50% or lower), delvery of VHP to the cabn, and aeraton to extract VHP from the cabn. Railcar Thermal and VHP Run Although the prmary focus of the work reported here was on wde-body arcraft, the opportunty was taken to demonstrate decontamnaton of a two-decker commuter ralcar. In ths case, a sngle decontamnaton unt was employed to demonstrate both thermal and VHP decontamnaton. The nlet and outlet hoses were placed n the end doors of the ralcar, usng door plugs manufactured on ste. Protocols The followng protocols were establshed n advance of the testng. was As noted above, work on the 747 was exploratory and so the am was smply to approach these condtons as closely as possble, rather than a pass/fal scenaro for the technology. 747 Stand-Alone Thermal Decontamination System The cabn of the 747 would be nstrumented wth relatve humdty sensors (one n the front and one at the rear of the cabn) and 36 thermocouples, and data were logged contnuously.
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At least three sets of data were to be collected, one of whch would be on the day of the Edgewood Chemcal Bologcal Center (ECBC) evaluaton and meetng the followng crtera. The target cabn surface would be mantaned at 60C for at least two hours. The temperature at the ar nlet would not exceed 65C, and the target relatve humdty would be 50%. The cargo area would be excluded from the evaluaton. 747 VHP Add-in The cabn would be equpped wth the same nstrumentaton used for the stand-alone thermal decontamnaton system. Addtonally, sx ATI hydrogen peroxde vapor sensors for measurng the workng concentraton of the VHP would be ncluded. Thrty Apex 6 log G. Stearothermophlus bologcal ndcators (BIs) would be placed throughout the cabn. Note: In the field work, chemcal ndcators (CIs) were colocated wth the BIs so as to supplement the peroxde sensors, although ths was not specfied n the protocol. Perpheral sensors would be placed around the arcraft, ncludng near the outlet used to flush the VHP, to demonstrate complance wth OSHA PEL and other relevant exposure lmts. Handheld sensor(s) wth manual data recordng would be used n leu of sutably calbrated automated sensors, not avalable on-ste. VHP concentratons would be montored on enterng the cabn after each run usng sutable nstrumentaton. A mnmum of three runs would be performed, ncludng one on the day of the formal evaluaton, wth observers from the FAA and ECBC present. All of the runs would be performed under the followng condtons: VHP concentraton would be mantaned between 125 200 ppm for at least two hours at all locatons sampled. The VHP concentraton would not be allowed to exceed 500 ppm at any locaton to mnmze the rsk of condensaton. VHP concentratons would be montored on enterng the cabn after each run to ensure that the readng dd not exceed 1 ppm for those runs n whch aeraton was allowed to run to completon. In vew of tme constrants, the run durng the ECBC (Rastog, 2007) and FAA vst would be termnated at 2 5 ppm, whle ensurng that the duraton of exposure for personnel harvestng the BIs was carefully montored so that no ndvduals exposure would exceed the OSHA 1 ppm TWA PEL. In the case of all runs, except that carred out on the day of the evaluaton, the montorng descrbed n the prevous paragraph would be repeated to detect any VHP out-gassng from porous meda wthn the cabn. Addtonal aeraton would be employed as found necessary, and the measurements would be repeated.
Railcar Thermal and VHP Run The montorng procedures for both the thermal and VHP decontamnaton runs would be smlar to those employed for the 747 but wth a reduced number of sensors. Ths would not be a formal evaluaton, as has already been noted, but would be an ntal demonstraton of capablty.
RESULTS
747 Stand-Alone Thermal Decontamination System It proved possble to heat the majorty of the 747 cabn to close to 60C and hold farly near to ths temperature for an extended perod wth the use of two thermal decontamnaton unts (Fgure 1). However, n some cases regons, t was not possble to hold at 60C for 2 hours, as stpulated n the protocol (Fgure 2). Surface temperatures n other locatons (e.g. adjacent to the nlet) were found to exceed 65C, wth a maxmum temperature of 71C beng observed where the ncomng ar stream mpnged on the cabn (Fgure 3). The two thermal decontamnaton unts appeared to be well matched to the thermal mass of the 747, whereas a sngle unt had a rather larger heatng capablty than that requred for a DC-9. An effort was made to sample the temperature at locatons throughout the cabn, encompassng surfaces comprsed of a wde range of materals and thermal masses. All temperatures specfied are surface temperatures, not ar temperatures. Some run-to-run scatter was apparent for runs conducted wth dentcal control parameters. Usng the 100 kW steam generator, t was not found possble to brng the cabn RH to above 20% (Fgures 4 and 5). 747 VHP Add-In The combned system appeared to be capable of controllng the VHP concentraton n the 747s cabn, based on the output from 8 hydrogen peroxde sensors (Thomas, 2007). It was possble to mantan an average cabn hydrogen peroxde concentraton of around 175 ppm under non-condensng condtons, whch should be sufficent to produce a sporcdal acton (concentratons above ~ 80 ppm are usually consdered sporcdal). The hydrogen peroxde concentraton measured adjacent to the nlet dd not exceed 275 ppm, and hence there does not appear to be a rsk of macroscopc condensaton of the peroxde (and localzed condensaton would requre pockets of hgh humdty). However, some condensed peroxde was apparent n the return ar cabnet of the thermal decontamnaton systems ar handler and at weather-nduced breaches to the temporary wooden door plugs.
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In a few cases, the 6 log G. Stearothermophlus bologcal ndcators (BIs) placed throughout the cabn dd not acheve complete kll. These BIs were placed n locatons where peroxde access proved dfficult to acheve (see Gale, 2007 for a note on the lmtatons of the label clams made by STERIS wth respect to occluded spaces). The only cases of extensve kll falures n large portons of the cabn were due to weather-generated equpment falures that caused condensaton of the peroxde (Thomas, 2007). Table 1 summarzes the data obtaned from the BIs. As n earler work on the DC-9, some ssues were encountered wth release of peroxde trapped n seat fabrcs, etc. Optmzaton of the aeraton cycle seemed to help sgnficantly n addressng ths problem, although ths stll remans an ssue. Ths work s descrbed n detal n another report (see Thomas, 2007). Railcar Thermal and VHP Run Although not formally evaluated, ntal work on the ralcar ndcated that t s possble to reach the targeted envronmental condtons for both thermal and VHP decontamnaton. The absence of absorbent surfaces wthn the ralcar made the removal of VHP durng post-decontamnaton aeraton much less challengng than was the case for the 747. A two-hour exposure at an average 250 ppm VHP concentraton deactvated all BIs placed n the ral car. Table 2 shows the kll results from the BIs.
DISCUSSION
747 Stand-Alone Thermal Decontamination System As already noted, the prmary focus of the work reported was on determnng the feasblty of scalng up of decontamnaton from the earler work on the DC-9 to the 747, rather than on optmzaton of the decontamnaton process tself. Hence, the ssues that were not addressed n the DC-9 work reman (Gale, 2007). In the nterests of brevty, they wll not be repeated here. Notwthstandng the modficatons made to the 747, the work performed on the AERF can be regarded as a reasonable analogue for decontamnaton of an actual arlner cabn (mnus the cargo area and ECS ducts) n that the thermal mass should stll be farly smlar to an actual wde-body arcraft, and most of the orgnal materals of constructon remaned n place. Most of the cabn was efficently heated, wthout resort to an ar dstrbuton system wthn the cabn. However, one locaton, adjacent to one of the cabn servce areas (galleys and lavatores), was found to have nsufficent arflow, so an extenson trunk was used to delver ar to ths locaton (Thomas, 2007). It s possble that, wth further optmzaton of the ar delvery system, the extenson trunk could be elmnated.
75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 0 5,000 10,000 15,000 20,000 25,000
Temperature (C)
Run A Run B Run C
Time (seconds)
Figure 1. Profile from an armrest towards the rear of the cabin
75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 0 5,000 10,000 15,000 20,000 25,000
Temperature (C)
Run A Run B Run C
Time (seconds)
Figure 2. Profile from an armrest towards the front of the cabin
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75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 0 5,000 10,000 15,000 20,000 25,000
Temperature (C)
Run A Run B Run C
Time (seconds)
Figure 3. Profile from an overhead area adjacent to inlet
100 90 80
Relative Humidity (%)
70 60 50 40 30 20 10 0 0 5,000 10,000 15,000 20,000 25,000
Run A Run B Run C
Time (seconds)
Figure 4. Relative humidity profile from the rear of the cabin
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100 90 80
Relative Humidity (%)
70 60 50 40 30 20 10 0 0 5,000 10,000 15,000 20,000 25,000
Run A Run B Run C
Time (seconds)
Figure 5. Relative humidity profile from the front of the cabin
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Table 1. Biological Indicator Results for 747 (Provided by Jim Thomas, STERIS Corporation) Record Run 1 BI Location 48 hr 7 day Record Run 2 48 hr 7 day Record Run 3 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
+ + +
+ + +
after the experments, one of the authors dd notce some resdual peroxde n the supply lnes, but t s hard to see how ths would have been apparent durng the demonstraton tself. The work conducted on the 747 s generally encouragng n that scale-up was acheved. However, ssues related to resdual peroxde remanng after aeraton must be addressed n any future work. Railcar Thermal and VHP Run Although not formally evaluated, no problems were encountered durng the ralcar decontamnaton demonstraton, and ths appears to be a successful ntal demonstraton of a capablty for decontamnatng such vehcles.
Cabn temperature on multple cabn surfaces exceeded the desred 60C. Ths was due to one of the two unts havng to be operated at 65C and the second at 85C, due to on-ste power lmtatons. It must be noted that the present trals were conducted on a very tght schedule and budget. It s lkely that gven a longer lead tme, more provng runs, and addtonal resources, the temperature control ssues can be addressed. Falure to reach a humdty of > 30% RH for rapd antvral efficacy (Rudnck et al., 2006) was dsappontng. However, ths does not appear to be a fundamental problem wth the system but a matter of exceedng the capacty of the exstng steam generator to humdfy a wde-body arcraft. Ths s an ssue that can be addressed easly n the future. Apart from the above, no sgnficant ssues were apparent that had not already manfested themselves n the DC-9 work. Indeed, the results are generally encouragng wth respect to the feasblty of scalng up thermal decontamnaton to wde-body arcraft. 747 VHP Add-In As n the case of thermal decontamnaton, ssues dentfied n the DC-9 work perssted wth the 747. However, progress does seem to have been made wth respect to mprovng the efficency of aeraton (Thomas, 2007). Nonetheless, n our opnon, ths s an ssue that stll needs to be addressed and one wth scope for further mprovement through optmzaton of the aeraton stage. It was noted n the ECBC report (Rastog, 2007) that there was evdence, post test, of the presence of resdual peroxde at a sgnficant, but unquantfied, concentraton. Unfortunately, t has not yet proved possble, after the fact, to dentfy exactly when and where any peroxde hotspot occurred. Durng break-down of the system
CONCLUSIONS
As a result of the field evaluaton of the stand-alone thermal decontamnaton system and the VHP add-n, scaled up for applcaton to a wde-body arcraft, the followng conclusons have been drawn: The thermal decontamnaton system appears to be capable of reproducng n the field the temperatures found n an earler study to be needed for an efficacous antvral process (Rudnck et al., 2006). Further work wll need to be done to mprove the temperature control to elmnate overheatng of cabn surfaces. Reachng a relatve humdty > 20% was found to be a problem, but ths appears to be easly addressable wth the addton of ether a larger capacty or second steam generator. The thermal decontamnaton + VHP add-n combnaton was found to be sporcdal at numerous locatons wthn the cabn. The mpact of ssues relatng to the falure to deactvate BIs n certan locatons wth lmted peroxde penetraton wll need to be addressed. Condensaton of peroxde wthn the cabn wll also need to be addressed n future work on a wde-body arcraft. More generally, ssues related to the presence of resdual peroxde n the cabn after aeraton need to be more fully addressed. Ths evaluaton of the 747 was conducted on a very lmted budget and a tght schedule. Furthermore, there were weather-related dsruptons that severely mpeded set up and operaton of the equpment. Gven more tme and resources, t s envsaged that most of the ssues of concern can be addressed. Although ths was not a formal evaluaton, the ntal outcome from the ralcar decontamnaton demonstraton appears to be promsng.
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REFERENCES
Gale, W.F., Prorok, B.C., Gale, H.S., Sofyan, N.I., Barbaree, J.M.,and Neely, W.C. (2006). Report on the Selection of Decontamination Technologies for Further Evaluation or Implementation, Auburn Unversty, Auburn, AL. Gale, W.F. (2007). Report on Field Evaluation of Whole Airliner Decontamination Technologies, Auburn Unversty, 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. Rudnck, S. and Spengler, J. (2006). Report on the Thermal Inactivation of Vaccinia Viruses on Surfaces, Department of Envronmental Health, Harvard School of Publc, Boston, MA. Thomas, J.A. (2007), Decontamination Feasibility Tests on a Boeing 747 Aircraft Passenger Cabin and Commuter Train Car With STERIS Vaporized Hydrogen Peroxide (VHP) Technology and an AeroClave, LLC High Velocity Air Handling System, STERIS Corporaton, Mentor, OH.
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