Which of the following statements is false regarding the use of alcohol disinfectants?

a. Their activity drops when diluted below 50% concentration.
b. Alcohols are good for surface cleaning of stethoscope bells and diaphragms.
c. They can damage rubber tubing.
d. They are considered sporicidal.

ANS: D
Alcohol disinfectants in the health care setting refer to either ethyl alcohol or isopropyl alcohol. Neither is considered a high-level disinfectant as a single agent, they are not sporicidal, and they do not penetrate protein-rich materials. Their activity drops when diluted below 50% concentra-tion. Alcohols are inactivated by protein and can damage rubber, plastics, and the shellac mount-ing of lensed instruments. Alcohol wipes are a good choice for disinfecting small surfaces, such as medication vial tops. Alcohols are also useful as surface disinfectants for stethoscopes, venti-lators, and manual ventilation bags.