The 2005 version of the Regulations came in to force on 6th April 2006, with the exception of the music and entertainment sectors, where the introduction was delayed for 2 years.  The Regulations were an update of the 1990 Regulations, and introduced new noise limits for protecting employees hearing.

The Regulations contain lower exposure action values, upper exposure action values and exposure limit values.  The action values and limit values are specified in terms of peak sound pressure values and overall noise exposure in terms of daily or weekly personal noise exposure.  The lower action values identify where hearing protection has to be made available to staff and other actions are required by employers.  The upper action value determines the level where hearing protection must be used by employees.  The exposure limit value is the maximum level that employees shall be exposed to when taking in to account noise control actions.