Within how many days must confirmation of a standard threshold shift (STS) take place?

The requirement for the confirmation of a standard threshold shift (STS) to take place is set at 21 days. This timeline is established to ensure that any potentially significant changes in an employee's hearing threshold, which could indicate hearing loss related to workplace noise exposure, are properly monitored and addressed promptly.

By utilizing a 21-day confirmation window, it allows sufficient time for follow-up audiometric testing to determine whether the initial STS is consistent or an isolated incident. This is critical for implementing any necessary interventions, such as further monitoring, engineering controls, or personal protective equipment adjustments, aiming to safeguard the employee's hearing health effectively.

This timeframe aligns with regulations and best practices in occupational health and ensures that employers can act on the information gathered from hearing tests to prevent further hearing degradation among employees.