1.1 This European standard specifies the minimum performance requirements and test methods of two types of sterilizers employing ethylene oxide gas as the sterilant, either as a pure gas or in admixture with other gases (whether supplied ready mixed or mixed at the point of use) in a temporarily sealed chamber. These sterilizers are intended to be used for medical, dental, pharmaceutical, veterinary and industrial or related purposes. The two types of sterilizers have been designated Type A and Type B respectively using the following criteria: - Type A sterilizers are capable of being programmed by the user; - Type B sterilizers are of limited size and provided with one or more pre-set operating cycles which cannot be varied by the user. The clauses of this standard apply to both types of sterilizer unless it is specifically indicated within the clause that it applies only to one of the types in particular. 1.2 This standard includes minimum performance and construction requirements for sterilizers working above or below atmospheric pressure: - To ensure that the process is capable of being used to sterilize medical products; - For the equipment and controls necessary to permit validation and monitoring of the sterilization process.