OSMT (Ontario Society of Medical Technologists) Practice Exam

A disinfectant may become ineffective if:

1. It is not kept cool

2. It is not at room temperature

3. Instruments are not dried properly before being immersed in it

4. The container is kept tightly sealed during storage

The correct answer is: Instruments are not dried properly before being immersed in it

The effectiveness of a disinfectant can indeed be compromised if instruments are not dried properly before being immersed in it. This is because water on the surfaces of instruments can dilute the disinfectant, leading to reduced efficacy. Water can also create a barrier that prevents the disinfectant from effectively contacting the microorganisms present on the instruments. Properly drying instruments ensures that the disinfectant can perform at its intended concentration and fully engage with the existing contaminants. The other considerations, while they may relate to the storage or handling of disinfectants, do not have the same direct impact on their efficacy during the disinfection process. For example, maintaining a disinfectant at an appropriate temperature is important for its stability, but not necessarily for its immediate effectiveness once applied.