Any safety manager will reasonably segregate personal protective equipment (PPE) into categories based on the hazards such equipment is designed to mitigate. Consequently, a full-face respirator is not the first thing that comes to mind when thinking about hearing protection. Earmuffs and earplugs have their place in a noisy environment, but a respirator? Likewise, employees working with chemicals may make daily use of a respirator, but with noise below the action level, one may be inclined to think of hearing protection as optional safety equipment.
It turns out that many common industrial chemicals are ototoxic (poisonous to the ears) and as damaging to employees’ hearing as the industrial noise to which they are often exposed. But exposure to noise and chemicals at the same time can be positively devastating to hearing. That’s because their effects are often synergistic rather than merely additive. In other words, the total damage is greater than the damage caused by the sum of the parts.