Help: EO sterilization & bioburden

Emanuel Meron ms_comp at
Sun Nov 23 16:40:54 EST 1997

Please help with the following problem:

Our company manufactures a medical device (single use instrument cover).
The device is sterilized by a contract sterilizer. Sterilization is by
Ethylene Oxide. Process was validated per EN 550. At validation time
bioburden was 10 to 15 CFU per product unit.

My question is: How high may product bioburden go without invalidating
the sterilization process? I know that the lower the bioburden the
better but I still need to set some practical limit for our production
people without imposing undue difficulties.

All help will be appreciated.

Emanuel Meron

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