Abstract Of Noise Regulations / Criteria / Data

PREAMBLE

Noise standards promulgated by the U.S. Federal Government are authorized by the "Noise Control Act of 1972". The "Supremacy Clause" of the U.S. Constitution: Article VI, sec. 2, states that where there is conflict, federal law prevails. However, courts have mainly ruled that more stringent regulations can be imposed by state or local government.

Federal Occupational Safety and Health Agency (OSHA) will typically regulate work place standards including all worker exposures. Federal Environmental Protection Agency (EPA) will generally regulate outdoor standards including air, water, and noise. Noise may be subject to two or more simultaneous jurisdictions.

The following synopsis of criteria may be incorporated, modified or superseded by pending ISO regulations. In any event, the reader is advised to contact the cognizant regulatory agency to determine what criteria are pertinent to their location and project.

OSHA 8-HOUR TWA

85 to 90 dBA, Hearing Conservation program; 90 dBA and higher, Engineering Controls

TYPICAL EPA

NAC Day (0700-2200 hrs) Night (2200-0700 hrs) L10 & L50
L50 L10 L50 L10
1 60 65 50 55
in
dBA
2 65 70 65 70
3 75 80 75 80  

Acceptable sound levels for the receiver are a function of the intended activity in that land area. The following noise area classifications are grouped and defined by the SLUCM numerical codes and descriptions.

Noise Area Classifications (NAC) include the following land activities.

NAC-1 Household / residential / Medical / Religious / Educational / Recreational / Transient Lodgings / Cultural / Correctional Institutions / ...etc.
NAC-2 Transit Terminals (Passenger & Freight) / Airport / Marine / Auto Parking / Restaurants / Wholesale & Retail Trade ... etc.
NAC-3 Manufacturing / Utilities / Printing / chemicals / Petroleum Refining / Primary Metals / Paper...etc.

THE COUNCIL OF EUROPEAN COMMUNITIES, EEC / 536

100 dBA maximum sound power (Re 1 pW) for engine-generators 2KVA and larger at 75% rated load in KW under designated measuring conditions.

ISO  Noise Rating (NR) Curves

Ambient Noise Levels at Night

NEMA