Which level of sanitation involves complete removal of visible soil?

Cleaning is the level of sanitation that involves the complete removal of visible soil, dirt, and organic matter from surfaces. This process is essential as it prepares surfaces for further decontamination steps, such as disinfection or sterilization, by ensuring that contaminants do not interfere with these processes. Effective cleaning is crucial in laboratory settings, especially when working with laboratory animals, as it helps maintain a hygienic environment, reducing the risk of disease transmission and ensuring the welfare of the animals involved in research.

Disinfection focuses on reducing the number of pathogenic microorganisms to a level considered safe but does not necessarily remove all visible dirt or organic material. Sterilization goes further by eliminating all forms of microbial life, including spores, typically through methods like steam sterilization or chemical agents, but does not pertain to the physical removal of dirt. Therefore, cleaning stands distinct as the foundation of sanitation practices, making it the correct answer in this context.