The Andersen Series 4 sterilizer has been approved by the FDA for the sterilization of endoscopes intended for human use.
Andersen is the first company in the world to achieve FDA registration for an Ethylene Oxide (EtO) sterilizer that uses a flexible sterilization chamber. The approval letter/certificate may be viewed here. The product concerned is the Andersen Series 4 sterilizer, pictured on the left. Indications for use include sterilization of an endoscope with a 1.7m long lumen with 0.7mm internal diameter. The sterilization cycle runs at 50°C and takes only 3 hours. The Series 4 cycle uses just 17.6g of EtO and does not require the use of deep vacuum or steam injection. Aeration may be carried out in the same cabinet. Residual EtO levels in a colonoscope will fall to levels acceptable for human use after 8 hours at 50°C. An optional abator is available, that will remove in excess of 99.9% of the EtO in the exhaust stream.
Flexible chamber technology has established itself in the low volume, low temperature sterilization market. Following on from the release of AAMI TIR56 in 2014, FDA approval will give the technology a further boost. There is also a current ISO New Work Item Proposal (NWIP) for a Technical Specification providing guidance on the Application of ISO14937 to the validation of sterilization cycles using flexible chamber EtO systems.