In regards to sterilizing 3ml injection pen cartridge vials.    Heres my plan - wondering what I have wrong - probably overloaded. I'm doing a test run.  Cartridges are packed 4 to a sterilization pouch - 3.5"x6.5".   I can get 4 packs per layer without overlapping. Place a terrycloth towel between layers, 8 layers - total of 32 packages, total of 128 cartridges.  The inner chamber is 3/4 full.  Following directions in the manual to vent air and fill with steam for 10 minutes, then close vent, bring up to 20PSI and vent again until pressure comes to about 5PSI (this last part wasn't in the manual, but I saw it mentioned elsewhere - seems like a good option to make sure all air is purged).  Close vent, bring back to 20PSI and hold between 17-20 PSI for 45 minutes.  I got some sterilization indicator tape and put a piece on each pouch.  Arranged so the tape is in the center of each layer on 2 of the 4 packages.  Remove packets from sterilizer and lay out on a wire shelf to air dry.  Misted the wire shelf with alcohol first to sterilize it.  Allow to dry completely.   I am not sure about these sterilization pouches... How does steam penetrate them to reach the items inside?  If steam can get through, then germs can probably get through.   Are they not sealed in these pouches to prevent contamination?  Or do they have to be dried and stored in a sterile environment too?    A lab pro contact told me I need to remove the plungers from the cartridges so steam can get in them-- which would require puncturing the cartridge tip with a needle to inject air to push the stoppers out.  But I don't understand how steam can penetrate the pouches.  I'd have to work the stoppers back into the vials while still in the pouches and after they dry.  Difficult but not impossible.  My concern with that is that the handling of them like that opens the door to contamination.  I would certainly wear gloves, but that doesn't eliminate all germs... There's still unsterile air all around them.  If the pouches don't seal the contents and keep them sterile, then what's the point of the pouches?  I have to think that just getting these things up to 259° for 45 minutes would be adequate... I don't see why the stoppers need to be pushed out first or how steam can penetrate the pouch to get inside the cartridge.  Ok, I probably just confused everyone.  I want to get this right, so I'm happy to talk it out and do whatever is necessary.  These will be used for SQ vitamin injections, so being perfectly 100% sterile isn't as critical as it would be for, say, IV injections.