Bacteriology, Sanitation, and Infection Control
Core concepts
This domain is about keeping clients and yourself safe. Know the difference between cleaning (removing visible debris), sanitizing (reducing pathogens to a safe level on surfaces and tools), disinfecting (destroying most pathogens on nonporous items with an EPA-registered hospital disinfectant), and sterilizing (destroying all microorganisms, including spores). Understand the chain of infection and the classes of pathogens: bacteria (cocci, bacilli, spirilla), viruses, fungi, and parasites. Know which are contagious and which are bloodborne.
Traps to expect
Questions blur sanitize vs. disinfect and disinfect vs. sterilize. Remember: disinfectants require full immersion for the label contact time, and porous items (files, buffers) cannot be effectively disinfected, so they are single-use. Another trap is confusing a bloodborne pathogen (HIV, hepatitis B) with a disease spread by direct contact or air. Also watch for "how often" questions: disinfect implements after each client, wash hands before and after every service.
Rule of thumb
"If it touches skin and can't be immersed, it's single-use." And "clean before you disinfect" because debris blocks the chemical.
Worked example
A barber drops a metal comb on the floor. Correct sequence: pick it up, clean it of debris, then fully immerse it in an EPA-registered disinfectant for the labeled time before reuse. Skipping cleaning or the contact time are the classic wrong answers.