What is the best method to test a PPE mask?

The vacuum test, whether conducted with or without the filter, is an effective method for assessing the fit and integrity of a personal protective equipment (PPE) mask. This method involves creating a negative pressure inside the mask and observing whether it maintains that pressure without any leaks. A successful vacuum test indicates that the mask forms an adequate seal against the wearer's face, which is crucial for ensuring the mask provides the intended level of protection.

Testing methods like the water seal test or particle filtration test focus on different aspects of mask performance. The water seal test checks for leaks in a mask by submerging it in water, which, while useful, is less reliable for confirming that the mask fits properly to face contours. The particle filtration test assesses how effectively the mask filters particulates but does not provide information about the seal on the user's face.

Visual inspection is another important step for overall safety, but it does not adequately assess the fit or performance of the mask. Therefore, while all these methods contribute to mask testing, the vacuum test stands out as the best method for ensuring a secure fit, critical for the mask's effectiveness in real-world use.