Respiratory Protection & PPE

Respiratory and hearing protection: N95 valved particulate respirators, KN95 and pleated face masks by the case, disposable face shields, and 3M PELTOR Optime over-the-head earmuffs rated 25 dB NRR. An N95 only performs to its rating if it seals to the face, which is why facial hair and a loose strap undo the filter entirely. A valve makes the mask easier to breathe through and cooler over a shift, but it vents unfiltered exhale, so it is a wearer-protection item rather than a source-control one. NRR is measured in a lab; the practical reduction at the ear is meaningfully less, so choose a margin rather than the exact number.