National Stock Number (NSN). Medical equipment identification
consisting of an applicable four-digit class code number plus the
nine-digit national item identification number.
North Atlantic Treaty Organization.
NAVFAC. Naval Facilities Engineering Command.
NCPC. National Capital Planning Commission.
National Capital Region.
National Council of Radiation Protection and measurements.
NEMA. National Electrical Manufacturers Association.
National Environmental Policy Act.
National Fire Protection Agency.
NIOSH. National Institute for Occupational Safety and Health.
NIST. National Institute of Standards and Technology.
Noise Criteria-Level (NC-LEVEL). Refers to a set of contours,
roughly corresponding to the ear's response to Sound Pressure
Level at various frequencies, which define the background sound
level existing within a space.
Noncombustible Material. A material (as defined in NFPA 220,
Standard on Types of Building Construction) that, in the form it
is used and under the conditions anticipated, will not ignite,
burn, support combustion, or release flammable vapors when
subjected to fire or heat. Materials reported as noncombustible
when tested in accordance with the Standard Test Method for
Behavior of Materials in a Vertical Tube Furnace at 750 degrees
C, ASTM E136, shall be considered noncombustible materials.
Nonflammable Anesthetic Agent. Refers to those inhalation agents
that because of their vapor pressure at 98.6 degrees F (37
degrees C) and at atmospheric pressure cannot attain flammable
concentrations when mixed with air, oxygen, or mixtures of oxygen
and nitrous oxide.