As a result of a European Union Physical Agents (Noise) Directive issued in 2001 new regulations, "The Control of Noise at Work Regulations 2005" came into force in April 2006.  These regulations set the following action and limit values:

Lower exposure action value:	a daily noise exposure level(LEP,d) of 80 dB(A) and a peak sound pressure level of 135 dB(C)
Upper exposure action value:	a daily noise exposure level of 85 dB(A) and a peak sound pressure level of 137 dB(C)
Exposure limit value:	a daily noise exposure level of 87 dB(A) and a peak sound pressure level of 140 dB(C)

An employee’s noise dose must be below the limit value when wearing hearing protection.

An employer must ensure that risk from exposure of his employees to noise is either eliminated at source or, where this is not reasonably practicable, reduced to as low a level as is reasonably practicable.

If a lower exposure action value is likely to be exceeded, a risk assessment must be carried out.  An employer must determine whether any employees are likely to be exposed to noise at or above one of the three above levels.

View the regulations.