General EHS Guidelines [Complete version] at: www.ifc.org/ehsguidelines
Environmental, Health, and Safety (EHS) Guidelines
GENERAL EHS GUIDELINES: ENVIRONMENTAL
NOISE MANAGEMENTWORLD BANK GROUP

barrier. Barriers should be located as close to the

1.7 Noise

source or to the receptor location to be effective

Applicability•

Installing vibration isolation for mechanical equipment

This section addresses impacts of noise beyond the property•Limiting the hours of operation for specific pieces ofboundary of the facilities. Worker exposure to noise isequipment or operations, especially mobile sources

covered in Section 2.0 on Occupational Health and Safety.

operating through community areas

Prevention and Control
Noise prevention and mitigation measures should be applied•advantage of distance and shielding•

where predicted or measured noise impacts from a project
facility or operations exceed the applicable noise level•••

Selecting equipment with lower sound power levels•

Installing silencers for fans•

Installing suitable mufflers on engine exhausts andcompressor components•

Installing acoustic enclosures for equipment casingradiating noise•

Reducing project traffic routing through communityareas wherever possible•emissions depend on the source and proximity of receptors.
Noise reduction options that should be considered include:

Taking advantage of the natural topography as a noise
buffer during facility design

sources is to implement noise control measures at source.53
Methods for prevention and control of sources of noise

Siting permanent facilities away from community areas if
possibleguideline at the most sensitive point of reception.52 The
preferred method for controlling noise from stationary

Re-locating noise sources to less sensitive areas to take

Planning flight routes, timing and altitude for aircraft(airplane and helicopter) flying over community areas•

Developing a mechanism to record and respond tocomplaints

Noise Level Guidelines
Noise impacts should not exceed the levels presented inTable 1.7.1, or result in a maximum increase in backgroundlevels of 3 dB at the nearest receptor location off-site.

Improving the acoustic performance of constructedbuildings, apply sound insulation•

Installing acoustic barriers without gaps and with acontinuous minimum surface density of 10 kg/m2 inorder to minimize the transmission of sound through the52 A point of reception or receptor may be defined as any point on thepremises occupied by persons where extraneous noise and/or vibration arereceived. Examples of receptor locations may include: permanent orseasonal residences; hotels / motels; schools and daycares; hospitals andnursing homes; places of worship; and parks and campgrounds.
53 At the design stage of a project, equipment manufacturers should provide

design or construction specifications in the form of “Insertion LossPerformance” for silencers and mufflers, and “Transmission Loss
Performance” for acoustic enclosures and upgraded building construction.

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Environmental, Health, and Safety (EHS) Guidelines
GENERAL EHS GUIDELINES: ENVIRONMENTAL
NOISE MANAGEMENTWORLD BANK GROUP

m to any reflecting surface (e.g., wall). In general, the noise

Table 1.7.1- Noise Level Guidelines 54

level limit is represented by the background or ambient noise

One Hour L Aeq (dBA)

Receptor

Daytime
07:00 - 22:00

Nighttime
22:00 - 07:00

Residential; institutional;
educational55

55

45

Industrial; commercial

70

70levels that would be present in the absence of the facility ornoise source(s) under investigation.

Highly intrusive noises, such as noise from aircraft flyovers
and passing trains, should not be included when establishingbackground noise levels.

Monitoring
Noise monitoring56 may be carried out for the purposes of
establishing the existing ambient noise levels in the area ofthe proposed or existing facility, or for verifying operational
phase noise levels.
Noise monitoring programs should be designed andconducted by trained specialists. Typical monitoring periods
should be sufficient for statistical analysis and may last 48
hours with the use of noise monitors that should be capableof logging data continuously over this time period, or hourly,
or more frequently, as appropriate (or else cover differing
time periods within several days, including weekday andweekend workdays). The type of acoustic indices recorded
depends on the type of noise being monitored, asestablished by a noise expert. Monitors should be locatedapproximately 1.5 m above the ground and no closer than 3
54 Guidelines values are for noise levels measured out of doors. Source:

Guidelines for Community Noise, World Health Organization (WHO), 1999.
55 For acceptable indoor noise levels for residential, institutional, andeducational settings refer to WHO (1999).

56 Noise monitoring should be carried out using a Type 1 or 2 sound level

meter meeting all appropriate IEC standards.

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