EFHSS Questions and Answers - Question Q00485

We have discovered in our CSSD, that containers made of plastic, wrapped in non-woven paper, are wet inside after sterilizing.
Not only when the packages are wet outside, but also when they are dry outside!

The containers contains instrumets used for orthopedic surgery, i.e. Charnley.

Could anyone please, give me some advice?

Lisbeth

I suspect many SSD managers have suffered this problem from time to time. The plastic trays do push the drying capabilities of a porous-load sterilizer to the limit, especially with orthopaedic trays where there is so much metal, and hence so much water produced. Sometimes the packaging may dry before all the water is removed, the packaging becomes non-porous and hence no more drying. This will produce the packs which are wet inside. The solution is not easy and you may have to experiment with packaging materials, tray liners, drying time, drying vacuum etc to reach the right conditions. The load characteristics are so different from the standard test loads that you will need to set up the sterilizer - or have a special cycle - for these loads. I suspect that managers may respond with their tricks to overcome this problem - I speak as an engineer.

Hope this helps - Peter Hooper, UK

Lisbeth

Place a wireless %RH/Temperature data logger inside a tray. Locate the tray in the most challenging zone of the sterilizer. The sensor can be programmed to collect data even every minute. Changing the drying times, and collecting humidity and temperature data profiles for each run, will allow you to determine the required drying time.

If you do not have access to wireless data loggers (made by MadgeTech, Omega, Dickson, Mesa Labs, etc...), you may be able to accomplish the same profiling with a thermocouple.

Paul J. Sordellini

Hi.

Such a load: Plastic container, Non woven paper, and Metal load IS A CHALLENGE!!!
Plastics, needs X4 condense than Steel to acheive an identical temperature.
Ad to these complications the difficulty to remove locked air from the container.
To achieve consistant (&) good results you need very good quality of steam, a very strong vacuum pump and to develop a pulsed drying stage. Air removal is very difficult.
Challenge the process!
It is possible!

miki

All this is a result of some physical laws.
The heat taken by steel and the heat taken by plastics is very different and the difference of heat given off in the cooling down process gives this moist on your instruments.
When both materials are united in one container you always have some wet load problems.
Ask a physician in your neighberhood about this and he will tell you.
I also have a problem of the same kind because I started to use some new containercovers in plastic from aesculap.
I will have to adjust some specifications on my steriliser to avoid this... I think.

Standing the plastic box on a metal tray base before wrapping helps to alleviate this problem.

Ros

Hi Lisbeth,

My advice is to change to aluminium sterile - containers where ever possible. They are reasonably light and have excellent drying properties, although costly. The use of disposable tray-liners helps, but they cannot be used with pre-formed instrument sets.
Check the effectivness of the vacuum pump, this varies greatly according to the manufacturerof the steriliser. Some plastic containers have perforated walls and base, these allow better drying.

NB: Plastic trays and containers with silicone mats (Example: Riwo-System Tray) for MIS endoscopic instruments can have residual condensate underneath the mats, but are dry on the outside, check these too.

Good luck
Linda

Lisbeth & colleagues

I would like to suggest that you contact the company who supplies these plastic instrument trays e.g Johnson & Johnson, Stryker etc. Get them to supply and pay for custom made stainless steel 3mm thick metal flash plates. These flash plates should fit underneath the set and be wrapped within the sterilisation wrap.

Kimberly-Clark Healthcare may also supply the metal flash plates as part of a conversion package to the One-Step Sterilisation wrap.