ANDERSEN EO Gas sterilizers claim that another load can be put while the sterilization of existing load is taking place. How does aeration take place in such sterilizers and doesnot the health care worker get exposed to high levels of EO gas in such sterilizers

Dear,

Information on the sterilization process and aeration in the Andersen EO gas sterilizers you can find on the following websites:

• www.anpro.com and
• www.anderseneurope.com

Andersen says the system complies with current OSHA regulations for personnel exposure.
In my opinion exposure of the staff to EO must be strictly limited. This is not the case here.

Moreover I wonder if this EO sterilizer complies with "EN 1422: Sterilizers for medical purposes, Ethylene oxide sterilizers, requirements and test methods".
Reliability and reproducibility of the process remain also debatable questions.

A lot of info on EO sterilization and a foresight on the future of EO sterilization in our hospitals you can find on the Q & A pages, category Low Temperature Sterilization.

Good luck,
Wim Renders

Dear,

In response to your question on operator exposure. The Andersen EOGas system is designed using negative pressure and sterilisation bags to allow operators to add and remove loads at any time. While this function may seem counterintuitive we have performed many tests both at our facility and at customer sites to show this is correct.

Our customers regularly monitor operator exposure every year and we keep a record of the results. These records have shown a dramatic reduction in operator exposure level across the last decade to levels which are well beneath OHSA requirements. I believe this is a result of better design and improved training of operators. You may be interested to know there is a update of the NIOSH study about to be released which has tracked cancer rates in 18,000 workers exposed to EtO in the USA over 40 years. This study shows that overall cancer rates in the group are below expected levels. While concerns still exist for the group of workers who were regularly exposed to levels of 50ppm and above on a daily basis for many years in the 1960s and 1970s, mostly in facilities with very large pallet chamber sterilizers, no concerns exist for the workers whose exposure was kept within OHSA guidelines.

On Wim's comment with respect to EN1422. I presume he refers to the more important EN550 and updated ISO11135 which is to be issued soon and will supercede EN550. It is becoming a requirement that all low temperature sterilizers in use in Europe for healthcare instruments need to be validated to an official standard. To achieve this will require a massive upgrade of most exising equipment in the field. For example you will need two calibrated temperature sensors which give readings independent of the main control system. You must measure relative humidity during a cycle. You must use at least 10 biological controls per cycle and validate a reduced incubation time. Andersen offers sterilization systems which can comply with these standards but understand that the customer base in Europe will be small given the cost of buying and maintaining such a system and the present focus on single use items. In Europe therefore we are establishing and running the systems ourselves on a contract basis for multiple clients rather than selling systems to single clients.

If you would like more information you can contact me on


Jonathan Lintott
Managing Director
Andersen Europe