Reference

Earmuffs only deliver their rated protection when the cushions form an unbroken seal against your head. This guide shows you how to wear earmuffs correctly: positioning the headband, clearing hair and eyewear arms, setting the right tension, choosing cap-mount versus over-head styles, and knowing when worn cushions need replacing.

The NRR on every earplug and earmuff is a laboratory number, not the protection you actually get on the floor of a plant. This guide shows you how to read the NRR on the EPA label, apply the OSHA 50 percent derating rule and the NIOSH (NRR-7)/2 formula, and calculate combined attenuation when you double up earplugs and earmuffs together.