How is a negative pressure fit check performed?

A negative pressure fit check is performed to ensure that a respirator or mask forms a proper seal against the wearer's face. This check is essential in lead abatement work to guarantee that workers are adequately protected from inhaling lead dust and other harmful contaminants.

The correct choice describes the process of covering the filter cartridges and breathing in. By doing this, the wearer creates a slight negative pressure inside the mask. If the mask is sealing well, the user will feel the mask being pulled toward their face as air is drawn in, rather than allowing outside air to enter through any leaks. This method effectively tests the integrity of the fit and provides immediate feedback about whether the respirator is providing a proper seal.

The other methods do not specifically verify the seal as effectively as the negative pressure method. For instance, simply covering an exhaust valve and breathing out can inform you about the respirator's function but does not accurately indicate if the fit is secure. Using a manometer would not typically be practical in this context, as it measures pressure but isn't designed for fit checks. Checking for leaks with soap and water is primarily used for identifying existing leaks but is not a method for checking the fit itself during wear.