BS 4142 - Methods for Rating and Assessing Industrial and Commercial Sound

Responses to sound can be subjective and are affected by many factors. This can include the margin by which sound exceeds the background sound level, time of day and change in the acoustic environment, as well as local attitudes to the source of the sound and the characteristic of the neighbourhood.

BS 4142:2014 has been amended. The new British Standard BS 4142:2014+A1:2019 Methods for rating and assessing industrial and commercial sound provides a method of assessing the impact of a source of industrial or commercial sound including sound from: 

• industrial and manufacturing processes
• fixed installations
• the loading and unloading of goods
• mobile plant and vehicles that is an intrinsic part of the overall sound emanating from premises or processes

The standard can be used to assess sound, including a change of sound, as a response to a complaint or as part of a planning application.  It supports current UK planning guidance and Environment Agency requirements on noise impact assessments. The standard does not include sound from passing vehicles on roads or railways.

BS 4142 is one of the UK’s most widely used standards for the assessment of environmental noise.

BS 4142 uses a 'rating level' – this is based on a comparison between the sound which is being assessed and the background sound which would exist without it. The rating level is then modified by any corrections for the character of the sound, be that tonal, impulsive, or intermittent.

Finally, the impact assessment is considered with respect to the context in which the sound will be heard. The impact assessment is modified appropriately to provide a final assessment which takes account of the ‘context’. Annex A in the standard provides several useful examples of assessments for users.

The standard has come a long way since the first version appeared in the Wilson Report of 1963. BS 4142 was last revised in 2014. 

This new version (June 2019) will ensure professionals are advised correctly to make valid and supportable planning decisions. The standard has been amended to improve clarity and to correct errors. The consistency of the assessment of the impact has been improved.

Users of BS 4142 include anyone who deals with environmental sound, including:

• Environmental Health Officers
• Noise consultants, and
• Planners needing assurance that any noise evidence supporting planning applications is sensible, coherent and reliable.