Alternative Room Disinfection Modalities –Pros and Cons - Use of Biocidal Surfaces for Reduction of Healthcare Acquired Infections - page 200

120-L sample of 0.004 ppm. When applying an occupational exposure limit to a
member of the general public, it is essential to apply a safety factor. If a 100-fold
safety factor were applied to the PEL, the exposure limit of 0.001 ppm could not be
detected using OSHA's validated sampling method. Currently there are no fully
validated methods for measuring hydrogen peroxide. OSHA's partially validated
method (VI-6) can detect as low as 0.043 ppm, and their other partially validated
method (ID-126-SG) can detect only 0.1 ppm. Since the PEL is 1.0 ppm, these
methods would not be low enough to determine the safety of a non-occupational
exposure.
If, at some point in the future, either fumigation or UVC irradiation are
determined to be effective, the cost efficiency should be determined. The assess-
ment of cost must consider more than just the vendor fees or purchase of the
equipment. The time that rooms are removed to be fumigated or irradiated should
be considered. Fumigation techniques using hydrogen peroxide vapor typically
reported a 2-4 h per room cycle time. A greater than 2-h delay could affect room
turnover rates and potentially create a significant burden on the short supply of beds
in hospitals. The downtime using UVC irradiation would be expected to be less, but
the medical or legal costs of overexposure to either ultraviolet radiation or chemical
fumigation must be considered. An additional cost is that rooms to be fumigated
must be checked by a qualified person for potential leakage or for potential
deleterious effects on the facility's ventilation system. The cost of exposure mon-
itoring should be factored into the total price of a fumigation or UVC irradiation
procedures.
9.5 Conclusion
Fumigation and ultraviolet germicidal irradiation in healthcare facilities and other
related institutions should be limited to those instances where the benefits clearly
exceed the risks of human exposure or environmental damage. Fumigation of an
unoccupied building following a bioterrorism incident would meet this criterion.
In situations where the building is occupied, and the potential for recontamination is
high, the benefits of fumigation do not appear to exceed the risks. There is limited
research on the effectiveness of UVC as a surface germicide. Therefore, its use
should be restricted to areas with a proven benefit such as upper air and ventilation
system coil disinfection. Before potentially risky procedures such as fumigation or
ultraviolet irradiation are considered, simpler and safer approaches such as
enhanced cleaning should be considered first.
References
1. Dancer SJ, White LF, Lamb J, Girvan EK, Robertson C (2009) Measuring the effect of
enhanced cleaning in a UK hospital: a prospective cross-over study. BMC Med 7:28