Processes using chlorine dioxide (CD) gas for the biological decontamination of Class II
laminar flow biological safety cabinets (BSCs) have been validated following a protocol
developed in conjunction with NSF International. This report reviews the protocol and
presents the results of the study. Trials were performed in type A1, A2, B1, and B2
cabinets from two different manufacturers. Exhaust and down-flow HEPA filters were
pre-loaded with particulates to enhance the validation challenge. Two methods of CD
generation were included within the trials, with one involving the injection of a specific
mass of CD gas dependent upon the BSC volume, and the other involving the maintenance of a
constant CD gas concentration over the duration of the exposure. In each of the more than
40 experimental trials, 12 biological indicators with ∼106 Bacillus atrophaeus
endospores were deployed at various locations within the BSC to monitor decontamination
efficacy.
The study validated and qualified CD as an alternative to formaldehyde gas as a
decontaminant for BSCs. Acceptable durations for CD exposure of less than 90 minutes were
established. Neither residuals from CD nor cabinet material degradation was observed
during the trials.
References
1.
AbrahamG., Le Blanc SmithP.
M., & NguyenS. (1997). The effectiveness of gaseous formaldehyde
decontamination assessed by biological monitoring. Journal of
the American Biological Safety Association, 2(1), 30–38.
2.
AcklandN. R., HintonM. R., & DenmeadeK.
R. (1980). Controlled
formaldehyde fumigation system. Applied Environmental
Microbiology, 39(3), 480–487.
3.
ButtnerM., CruzP., StetzenbachL., Klima-CombaA., StevensV., & CroninT. (2004). Determination of the efficacy of two building
decontamination strategies by surface sampling with culture and quantitative PCR
analysis. Applied Environmental Microbiology, 70, 4740–4747.
4.
CheneyJ.
E., & CollinsC.
H. (1995). Formaldehyde
disinfection in laboratories: Limitations and hazards. British
Journal of Biomedical Science, 52, 195–201.
5.
CzarneskiM.
A., & LorcheimP. (2008). Validation of chlorine dioxide
sterilization. In AgallocoJ. and CarletonF. (Eds.), Validation of pharmaceutical processes (3rd
ed.) (pp. 281–287). New
York: Inform Healthcare,
Inc.
6.
FaveroM.
S., & BondW. W. (2001). Chemical disinfection of medical and surgical
materials. In BlockS. (Ed.), Disinfection, sterilization, and preservation (p.
888). Philadelphia: Lippincott, Williams & Wilkins.
7.
FinkR., LibermanD. F., MurphyK., LupoD., & IsraeliE. (1988). Biological safety cabinets: Decontamination or
sterilization with paraformaldehyde. American Industrial Hygiene
Association Journal, 49, 277–279.
8.
HalvorsonH.
O., & ZieglerN.
R. (1932). Application
of statistics to problems in bacteriology. Journal of
Bacteriology, 25, 101–120.
9.
HawleyR.
J., & KozlovacJ.
P. (2005).
Decontamination. In LindlerL., LebedaF., & KorchG. (Eds.), Infectious diseases: Biological weapons defense: Infectious diseases and
counterterrorism (pp. 333–348).
Tottowa, NJ: Humana Press,
Inc.
10.
International Agency for Research on
Cancer. (2004). Formaldehyde, 2-butoxyethanol and
1-tert-butoxy-2-propanol. IARC monographs on the evaluation of carcinogenic risks to humans. 88. Available at: www.iarc.fr/ENG/Press_Releases/archives/pr153a.html. Accessed online 2008.
11.
JengD.
K., & WoodworthA.
G. (1990). Chlorine
dioxide gas sterilization under square-wave conditions. Applied
Environmental Microbiology, 56, 514–519.
12.
JoslynL.
J. (2001). Gaseous
chemical sterilization. In BlockS. (Ed.), Disinfection, sterilization, and preservation (pp.
337–360). Philadelphia: Lippincott, Williams & Wilkins.
13.
KnappJ., & BattistiD. (2001). Chlorine dioxide. In BlockS. (Ed.), Disinfection, sterilization, and preservation (pp.
215–228). Philadelphia: Lippincott, Williams & Wilkins.
LeoF., PoissonP., SinclairC. S., & TallentireA. (2005). Design, development and qualification of a
microbiological challenge facility to assess the effectiveness of BFS aseptic
processing. PDA Journal of Pharmacy Science Technology, 59, 33–48.
16.
LuftmanH.
S. (2005).
Neutralization of formaldehyde gas by ammonium bicarbonate and ammonium
carbonate. Applied Biosafety: Journal of the American Biological
Safety Association, 10(2), 101–106.
17.
LuftmanH. S., RegitsM. A., LorcheimP., CzarneskiM. A., BoyleT. & AcetoH. (2006). Chlorine dioxide gas decontamination of large animal
hospital intensive and neonatal care units. Applied Biosafety:
Journal of the American Biological Safety Association, 11(3), 144–154.
18.
LuftmanH.
S., & RegitsM.
A. (2008). B. Atrophaeus
and G. Stearothermophilus biological indicators for chlorine dioxide gas
decontamination. Applied Biosafety: Journal of the American
Biological Safety Association, 13(3), 143–157.
19.
McDonnellG.
E. (2007). Antisepsis,
disinfection and sterilization–Types, action and resistance. Washington, DC: AMS
Press.
20.
MunroK., LanserJ., & FlowerR. (1999). A comparative study of methods to validate
formaldehyde decontamination of biological safety cabinets. Applied Environmental Microbiology, 65(2), 873–876.
21.
National Sanitation Foundation. (2007a). National Sanitation Foundation: Standard No. 49 for Class
II (Laminar Flow) Biosafety Cabinetry.
22.
National Sanitation Foundation. (2007b). Annex G–Recommended microbiological decontamination
procedure, National Sanitation Foundation: Standard No. 49 for Class II (Laminar Flow) Biosafety Cabinetry, G1–G3.
23.
PflugI. J., HolcombR. G., & GómezM.
M. (2001). Principles of
the thermal destruction of microorganisms. In BlockS. (Ed.), Disinfection, sterilization, and preservation (pp.
112–123). Philadelphia: Lippincott, Williams & Wilkins.
24.
PrinceN., & PrinceD.
L. (2001). Principles of
viral control and transmission. In BlockS. (Ed.), Disinfection, sterilization, and preservation (pp.
543–571). Philadelphia: Lippincott, Williams & Wilkins.
25.
RogersJ., SabourinC. L., TaylorM. L., RiggsK., ChoiY. W. & RichterW.
R. (2004a).
Environmental technology verification report: CDG Research Corporation
bench-scale chlorine dioxide gas: Solid generator. Battelle. www.epa.gov/etv/pubs/11_vr_cdg.pdf. Accessed online 2008.
26.
RogersJ., SabourinC. L., TaylorM. L., RiggsK., ChoiY. W. & RichterW.
R. (2004b).
Environmental technology verification report: CERTEK, Inc. 1414RH formaldehyde
generator/neutralizer. Battelle. Available at: www.epa.gov/etv/pubs/11_vr_certek.pdf. Accessed online 2008.
27.
SpinerD.
R., & HoffmanR.
K. (1971). Effect of
relative humidity on formaldehyde decontamination. Applied
Microbiology, 22, 1138–1140.
28.
TaylorL. A., BarbeitoM. S., & GremillionG.
G. (1969).
Para-formaldehyde for surface sterilization and
detoxification. Applied Microbiology, 17, 614–618.
29.
U.S. Department of Health and Human
Services. (2007). Biosafety in microbiological and
biomedical laboratories (5th ed.) (pp. 303–341). Washington: U.S. Government Printing Office.
30.
U.S. Environmental Protection
Agency. (2005). Compilation of available data on building
decontamination alternatives. Available at: www.epa.gov/NHSRC/pubs/600r05036.pdf. Accessed online 2008.
31.
USP 31/NF 26. (2008).
<1035> Biological indicators for sterilization. United States Pharmaceutical Corporation, 399–402.
32.
WestphalA. J., PriceP. B., LeightonT. J., & WheelerK.
E. (2003). Kinetics of
size changes of individual Bacillus thuringiensis spores in response to changes in
relative humidity. Proceedings of the National Academy of
Sciences, 100, 3461–3466.
33.
YoungS.
B., & SetlowP. (2003). Mechanisms of killing Bacillus subtilis spores by
hypochlorite and chlorine dioxide. Journal of Applied
Microbiology, 95, 4–67.
