Interpreting and understanding microbial data in validation of ethylene oxide sterilization processes.

Ethylene oxide (EtO) sterilization validation programs are based on historical data, industry experience, and theoretical knowledge. When designing a specific program, the knowledge and experience of the individuals responsible often determines how accurately these data, experiences, and theories are applied. The assumptions and premises that form the foundation for the validation program are critical to the ultimate safety ofproducts distributed to the marketplace. Demonstrating appropriate microbial lethality is the ultimate purpose of sterilization validation. When using EtO processes, this is usually dependent on the proper use of biological indicators (Bls) in conjunction with the specific product, load, and cycle to be validated. The authors discuss the use of Bls, determination of microbial lethality, process controls, and variables related to these subjects in order to assist validation teams in designing successful validation programs, and/or problem solving when unexpected results are obtained.