Which of the following best describes cross-contamination?

Cross-contamination refers to the transfer of harmful microorganisms from one surface, substance, or individual to another, which can lead to contamination and the spread of infection. This process often occurs when tools or equipment are used interchangeably without proper cleaning or when surfaces come into contact with contaminated items.

The correct answer highlights the essence of cross-contamination by emphasizing the movement of dangerous pathogens, and it recognizes the potential health risks involved in such actions. Understanding cross-contamination is crucial in the cosmetology industry to maintain hygiene and client safety.

The other options focus on preventive measures — such as cleaning tools or disinfecting surfaces — but do not capture the definition of cross-contamination itself. These practices are important in minimizing the risk of cross-contamination, yet they describe actions rather than the process of transferring microorganisms.