Mask seal refers to the tight fit between a respirator or breathing mask and the wearer’s face, ensuring that air is filtered through the mask rather than leaking in from the sides. A proper seal is critical for effective protection against airborne particles, smoke, or chemical vapors. Users are trained to perform seal checks before each use, adjusting straps and positioning to achieve a secure fit. Facial hair, improper sizing, or damage can compromise the seal, reducing protection. Regular inspections and fit-testing are standard in occupational safety programs. Maintaining a good mask seal is a simple yet vital step in safeguarding respiratory health during hazardous conditions, ensuring that protective equipment functions as intended.