California Cosmetology Written ExamSafety and Infection ControlMedium
A nail technician keeps her quaternary ammonium disinfectant solution in an open, uncovered plastic tub throughout her shift for easy access between clients. Why does this violate proper disinfection practice?
- ACalifornia law requires all disinfectants be stored only in glass containers
- BUncovered containers cause the solution to become more concentrated over time
- CLeaving the container open speeds up the required contact time
- DOpen exposure increases evaporation and contamination, reducing disinfecting strength
Show answer & explanationAnswer & explanation
Correct answer: D. Open exposure increases evaporation and contamination, reducing disinfecting strength
Disinfectant solutions must be kept in covered containers to prevent evaporation, airborne contamination, and reduction of the active ingredient's effectiveness, per manufacturer instructions and Title 16 requirements.
Why the other options are wrong
- A. There is no glass-only container requirement.
- B. Evaporation reduces effective concentration; it does not strengthen it usefully.
- C. Contact time is unaffected by whether the lid is open.
Covered Disinfectant Containers
Disinfectant solutions must be stored in covered, labeled containers to prevent evaporation and contamination that weaken disinfecting effectiveness.
- Keep containers covered/closed when not in use
- Evaporation reduces active ingredient concentration
- Label containers with contents and mix date
Memory trick: 'Lid on tight keeps the germs out of sight.'