ANTIFLASH CLOTHING--Intended to protect
AIR BLAST--The shock wave that is produced in the
personnel from transient high temperatures that
air by an explosion. The shock wave initially travels
may occur from the use of high explosive weapons
outward at a velocity of approximately seven times
and from being burned in a fire. Antiflash clothing
the speed of sound at high overpressures. It will then
consists of an antiflash hood and antiflash gloves.
gradually slow down to a sonic speed of about
APPROVED (FOR THE PURPOSE)--Equipment
1,000 fps at low overpressures.
or materials that have been tested, evaluated, and
AIR BLAST INJURY--Personnel can be picked up
determined to be acceptable by a recognized testing
and thrown by the blast. They receive their injuries
laboratory or inspection agency according to the
upon landing. The extent of the injuries will depend
requirements of a particular code or specification
upon the velocity of the body's movement, the
f o r a p a r t i c u l a r p u r p o s e , e nv i r o n m e n t , o r
nature of the object with which the body collides,
and the nature of impact, whether glancing or solid.
AQ U E O U S F I L M - F O R M I N G F OA M F I R E
EXTINGUISHER (AFFF)--Used to provide a
AIRBURST--A burst where the point of detonation is
vapor seal over a small fuel spill, to extinguish small
below an altitude of 100,000 feet, and the fireball
class BRAVO fires (such as deep-fat fryers), and for
does not touch the surface of the earth. Air blast,
standing fire watch during hot work.
thermal radiation (heat and light), electromagnetic
AQUEOUS FILM-FORMING FOAM (AFFF)--
pulse, and initial nuclear radiation (neutron and
AFFF, also known as "light water," is a synthetic,
gamma rays) are produced around the point of
film-forming foam designed for use in shipboard
AIR CHANGE--The process of introducing a volume
AQUEOUS POTASSIUM CARBONATE (APC)--
of air into a compartment that is equal to the volume
Are installed in Navy ships to provide protection for
of the compartment while simultaneously removing
galley deep-fat and doughnut fryers and their
an equal volume. Because of mixing, only 65
exhaust systems. Aqueous potassium carbonate is
percent of the air originally in the compartment is
specifically formulated to extinguish fire in the
removed in one air change.
reservoirs by combining with the hot cooking oil
surface to form a combustion-resistant soap layer,
AIR CONTAMINANT--A substance or material that
thereby cutting off the grease from its source of
atmosphere, usually occurring in the form of
AQUEOUS SOLUTIONS--A pH of 7 indicates a
aerosols, dusts, fumes, mists, gases, and vapors.
neutral solution; values below 7 indicate acid
AIR LOCK--A shipboard passageway with a
solutions and values.
quick-acting watertight (QAWT) door on either
ATHWARTSHIP--The athwartship structure consists
end. Only one door is opened at a time to prevent the
of transverse frames and floors and is the crosswise
flow of air from a pressurized part of the ship to an
portion of the ship.
unpressurized area. Air locks are also equipped
AT M O S P H E R E -- T h e i m m e d i a t e g a s e o u s
with fittings to allow purging of contaminated air.
surrounding of a particular location or confined
ALPHA (A) FIRES--Those that occur in such
space, including normal air plus any air
ordinary combustible materials as wood, cloth,
paper, upholstery, and similar materials.
ATMOSPHERIC IONIZATION--An increase in the
density of electrons in the atmosphere around a
ALPHA PARTICLES--A form of ionizing nuclear
nuclear burst. These electrons affect radio and radar
r a d i a t i o n c o n s i s t i n g o f p o s i t ive l y c h a rg e d
signals by removing energy from the waves.
subatomic particles emitted by some radioactive
materials. An alpha particle is identical to the
ATOM--An atom is made up of tiny particles known as
nucleus of a helium atom in mass, structure, and
electrons, protons, and neutrons. The relative
electrical charge but an alpha particle's energy level
number of these small particles determines the
attributes of an element.
is higher due to its speed.