Guidance

ANNEX 3 Exposure Limits

Published 18 September 2025

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This publication is available at https://www.gov.uk/government/publications/mgn-658-mf-amendment-1-control-of-noise-at-work-regs-2007/annex-3-exposure-limits

PART 1 

Daily Personal Noise Exposure Levels 

  1. The daily personal noise exposure level, LEP,d, which corresponds to LEX,8h defined in international standard ISO 1999: 1990 clause 3.6, is expressed in decibels and is ascertained using the formula:

 Where - Te is the duration of the person’s working day, in seconds; 

               T0 is 28,800 seconds (8 hours); and 

is the equivalent continuous A-weighted sound pressure level, as defined in ISO 1999: 1990 clause 3.5, in decibels, that represents the sound the person is exposed to during the working day. 

2. If the work is such that the daily exposure consists of two or more periods with different sound levels, the daily personal noise exposure level (LEP,d) for the combination of periods is ascertained using the formula: 

Where - n is the number of individual periods in the working day; 

              T1 is the duration of period i; 

            (LAeq,T)i is the equivalent continuous A-weighted sound pressure level that represents the sound the person is exposed to during period i; and  

is equal to Te, the duration of the person’s working day, in seconds. 

PART 2 

Weekly Personal Noise Exposure Levels 

  1. The weekly personal noise exposure, LEP,w, which corresponds to

defined in international standard ISO 1999: 1990 clause 3.6 (note 2) for a nominal week of five working days, is expressed in decibels and is ascertained using the formula: 

Where - m is the number of working days on which the person is exposed to noise during a week; and (LEP,d)i is the LEP,d for working day i. 

 PART 3 

Peak Sound Pressure Level 

  1. Peak sound pressure level, LCpeak, is expressed in decibels and is ascertained using the formula: 

 Where - pCpeak is the maximum value of the C-weighted sound pressure, in Pascals (Pa), to which a person is exposed during the working day; and 

               p0 is 20 μPa.

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