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About Determining
Breathable Area Of Sterilisation Package?
For effective EtO sterilisation the
packaging material must be breathable to allow the high-humidity
EtO gas mixture to infiltrate the package. A partial vacuum is
drawn before and after the cycle to facilitate the movement (in
and out)of the EtO and moisture vapor.
If the package does not have
sufficient permeability, the process will be ineffective.
A packaging that allows a breathable
barrier allows sterilant to permeate during the sterilisation
process while prohibiting the penetration of microorganisms during
handling and storage, after sterilisation. The total package
porosity of a sterilisable pouch which is dependent on the gas
flow and surface area is a key for sterilisation and aeration
phases of ethylene oxide gas sterilisation processes. The cycle
and aeration times decrease as the porosity increases. Hence a
smaller porous area is ample.
Determination of porous area
requires knowledge of some specific characteristics. Breathable
surface area, package volume, secondary and tertiary packaging,
and peel force are all factors that determine porosity
limitations. The worst case average porous area, the volume of the
package and the gas exchange rate for each part of the EtO cycle
at a minimum is needed for determining the porosity. The end
sterilisation testing is also needed to qualify a package design.
Product families of worst-case design and cycles are helpful
defining the limitation of sterilisation testing, but optimizing
the porosity of a package for an EtO cycle is a continuous
process.
Ref:
http://www.pmpnews.com/article/sterilization-packaging-perspective
http://www.rollprint.com/pdf/rpp_tp01_mddi.pdf.
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