unintentional event resulting in fatality, injury, illness, or property
ANSI. American National Standards
Institute. A private, non-profit organization that administers and coordinates
voluntary industry standards in the United States. ANSI standards have
been developed for equipment such as safety goggles, helmets, power
tools, elevating work platforms, and roadway lighting equipment [ANSI
Anthropometry. The technology
of measuring human physical traits such as size, reach, mobility, and
ASTM. American Society for
Testing and Materials. A private, non-profit organization that provides
an international forum for the development and publication of voluntary
consensus standards for materials, products, systems, and services.
ASTM standards include those for test methods for determining slip-resistance,
design and construction guidelines for safe walking surfaces, design
and installation of grab bars, and design and manufacture of amusement
park rides [ASTM Web site].
Attention. Direction and concentration
of cognitive resources. "Divided attention" occurs in situations in
which two or more separate tasks or mental operations must be attended
simultaneously, for example, looking for road signs and scanning traffic
while steering a vehicle. "Focused attention" occurs in situations in
which one information source must be attended to the exclusion of others,
for example trying to find a particular road sign in a group of road
signs. "Selective attention" occurs in situations in which one source
of information is inappropriately monitored to the exclusion of other
relevant information sources, such as being so engrossed in talking
on a cell phone that a driver misses his freeway exit.
state of bodily equilibrium.
Barrier guard In machine guarding
terminology, a rigid shield or device that covers hazard points on a
machine to prevent accidental and injurious contact with body parts,
or to control hazardous ejection and emissions from the machine such
as flying chips, air contaminants and noise. Syn. Machine guard.
Biomechanics. A discipline
that studies various aspects of physical movements of the body and body
Boom. A long pivoting structure
or arm that extends from an upright to lift or carry something, such
as on a crane or backhoe.
Brightness. The subjective
attribute of light intensity in which brightness implies higher light
intensities and dimness implies lower light intensities.
CAL-OSHA. California Division
of Occupational Safety and Health. (See OSHA) [Cal-OSHA Web site].
Candela. Abbr. cd. A unit of
luminous intensity equal to 1/60 of the luminous intensity per square
centimeter of a blackbody radiating at the solidification temperature
of platinum. Also called "candle" or "standard candle" or "new candle".
Coefficient of friction. The
ratio of the friction force between two objects and the force pressing
the objects together. "Static coefficient of friction" is
the ratio of the hoizontal force needed to initiate a slipping
action of an object along a surface, and the vertical force on the surface.
"Dynamic coefficient of friction" is the ratio of the horizontal
force needed to continue a slipping action of an object along
a surface, and the vertical force on the surface. A higher coefficient
indicates greater surface traction.
Cone. In eye physiology, a
cone-shaped photoreceptor in the retina of the eye responsible for fine
visual acuity and color vision. Cones function only at daylight levels
Contaminant. An undesirable
liquid or solid material on a walkway surface. Contaminants pose slip
and trip hazards.
Contrast. The difference in
luminance between two areas.
Contrast ratio. A mathematical
expression describing the difference in luminance between two areas;
the contrast ratio can be expressed as L1/L2 or as (L2L1)/L2, where
L1 is the luminance of the first area and L2 is the luminance of the
Control. In human-machine interaction,
a mechanism for regulating or guiding the operation of a tool, apparatus,
machine or other system; examples include push button, switch, knob,
wheel, lever, and pedal.
Dark adaptation. The physical
and chemical adjustments of the eye and visual system that make vision
possible in low levels of illumination by increasing its sensitivity
Decibel. A measure of sound
Display. Any method of presenting
information, such as a highway sign, warning buzzer or TV monitor.