What is checked during a fit check of respiratory equipment?

During a fit check of respiratory equipment, both positive and negative pressure checks are conducted to ensure the proper seal and functionality of the respiratory protection being used.

A positive pressure check typically involves using the respirator's exhalation valve to see if it holds air when the user exhales, indicating that the seal is intact and preventing outside air from entering the respirator. This is crucial for protecting against hazardous airborne substances.

Conversely, a negative pressure check assesses the integrity of the respirator by having the user inhale while blocking the filter or inhalation valve. If the respirator collapses slightly against the face, this also signifies a good seal, ensuring that no contaminants can bypass the respirator.

Both checks are fundamental components of a comprehensive fit check, as they ensure that the equipment will function properly in real-world conditions, offering the wearer optimal protection against asbestos or other harmful airborne particles. Thus, both types of pressure checks are necessary to ensure the respirator fits well and is in proper working order to safeguard the user effectively.