Chapter 1: Infection Prevention and Control

1.5 Principles of Asepsis

Critical Thinking Exercises: Questions, Answers, and Sources / References

Critical thinking questions are in bold type, and the answers are italicized. Additional resources or references are provided below.


  1. When should a sterile field be opened (under normal circumstances)?

A sterile field should be opened very close to the time it will be used. One of the principles of asepsis is that sterile fields left open to air for extended periods of time are considered contaminated.


2. What part of the sterile field is considered non-sterile?

The outer 2.5 cm (1 inch) border is considered non-sterile.


Perry, A. G., Potter, P. A., & Ostendorf, W. R. (2017). Clinical nursing skills and techniques (9th ed.). Elsevier; Mosby.