In the rule proposed in August 2009, the Environmental Protection Agency developed three primary label requirements that manufacturers must use to identify a hearing protector’s intended protection:
- Passive devices rely solely on their structure to block the transmission of sound into the ear canal without the use of electronic elements. These labels contain a single range.
- Active devices use electrical and structural elements, either alone or in combination, to reduce noise transmitted to the ear canal. These labels contain two ranges – with electronic activation and while passive.
- Impulsive devices provide a range of low-level passive hearing protection and protection in high-level environments (those that peak at greater than 140 dBA). These labels include two ranges – one for continuing passive noise and one for impulsive.
Source: Environmental Protection Agency