Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam 2025 - Free Medical Laboratory Science Practice Questions and Study Guide

The most critical part of a biological safety cabinet is the high-efficiency particulate air (HEPA) filter. This filter plays a vital role in ensuring a sterile environment by capturing airborne contaminants that may pose a risk to laboratory personnel and the integrity of the experiment. The HEPA filter is designed to trap at least 99.97% of particles that are 0.3 micrometers in diameter, which includes most microorganisms and cellular debris. This capability is essential in protecting both the user from potential exposure to hazardous biological agents and the samples being handled from contamination.

The effectiveness of a biological safety cabinet hinges significantly on the HEPA filter, as it is responsible for filtering the air that enters the cabinet and providing a sterile work environment. Therefore, the presence and proper functioning of this filter are paramount in maintaining safety protocols in the laboratory setting.