Which of the following is a typical characteristic of a disinfectant?

A typical characteristic of a disinfectant is that it must be mixed with water. Many disinfectants are concentrated solutions that require dilution in water to achieve the correct strength for effective disinfection. This dilution activates the properties of the disinfectant to eliminate pathogens effectively, ensuring that it operates at the required potency.

While some disinfectants can be used directly without dilution, most commercial products are designed to be mixed with water to optimize their effectiveness against germs and viruses. This is an essential practice in maintaining hygiene standards in environments such as salons, where proper sanitation is crucial.

The other options present characteristics that are not typical of disinfectants. Not all disinfectants are safe for all surfaces, as some can be harsh and damage certain materials. Furthermore, disinfectants do not have a perpetual lifespan; many have a limited shelf life and may lose efficacy over time or after repeated use. Finally, while some disinfectants may begin to work shortly after application, the efficacy usually needs a specified contact time to ensure all pathogens are effectively killed.