Gas sterilization

The most interesting issue with the
list is the reference to “gas
sterilisation” which has the phrase
“vapour phase sterilisation” following
it in parentheses. In this section two
methods of sterilisation by gas are
described: alkylating agents, which is
principally ethylene oxide (commonly
used to sterilise plastics, especially
those that might become embrittled
by gamma radiation); and oxidising
agents, which is principally hydrogen
peroxide in the vapour form. With
hydrogen peroxide vapour, which is
the most common means of treating
the inside environment of an isolator,
it is more common to use the term
‘decontamination’ (or
biodecontamination) rather than
‘sterilisation’. Indeed, in this author’s
experience, regulatory agencies such
as the MHRA stress that hydrogen
peroxide vapour is not a sterilant
(primarily because it cannot penetrate
the item being sterilised). This
means, with aseptic processing
isolators, for instance, product
contact parts (such as filling needles
and stopper bowls) are sterilised
separately and fitted in place prior to
running the hydrogen peroxide cycle.