Basic Calculations for Occupational Safety and Environmental Health Professionals - Mathematics and Statistics for the Environment - page 390

Hot work —Work involving electric or gas welding, cutting, brazing, or similar flame or spark-
producing operations.
Human factor engineering/ergonomics —For practical purposes, the terms are synonymous,
and focus on human beings and their interaction with products, equipment, facilities, pro-
cedures, and environments used in work and everyday living. The emphasis is on human
beings (as opposed to engineering, where the emphasis is more strictly on technical engi-
neering considerations) and how the design of things influences people. Human factors,
then, seek to change the things people use and the environments in which they use these
things to better match the capabilities, limitations, and needs of people (Sanders and
McCormick, 1993).
Ignition temperature —The temperature at which a given fuel bursts into flame.
Illumination —The amount of light flux a surface receives per unit area; may be expressed in
lumens per square foot or in foot-candles.
Impulse noise —A noise characterized by rapid rise time, high peak value, and rapid decay.
Incident —An undesired event that, under slightly different circumstances, could have resulted
in personal harm or property damage; any undesired loss of resources.
Indoor air quality (IAQ) —The effect, good or bad, of the contents of the air inside a struc-
ture on its occupants. While usually temperature (too hot and cold), humidity (too dry
or too damp), and air velocity (draftiness or motionless) are considered “comfort” rather
than indoor air quality issues, IAQ refers to such problems as asbestosis, sick building
syndrome, biological aerosols, and ventilation issues concerning dusts and fumes, among
others.
Industrial hygiene —The American Industrial Hygiene Association (AIHA) defines industrial
hygiene as “that science and art devoted to the anticipation, recognition, evaluation, and
control of those environmental factors or stresses—arising in the workplace—which may
cause sickness, impaired health and well-being, or significant discomfort and inefficiency
among workers or among citizens of the community.”
Ingestion —Entry of a foreign substance into the body through the mouth.
Injury —A wound or other specific damage.
Interlock —A device that interacts with another device or mechanism to govern succeeding
operations, such as the interlock on an elevator door that prevents the car from moving
unless the door is properly closed.
Ionizing radiation —Radiation that becomes electrically charged (i.e., changed into ions).
Irritant —A substance that produces an irritating effect when it contacts skin, eyes, nose, or
respiratory system.
Job hazard (safety) analysis —The breaking down into its component parts of any method
or procedure to determine the hazards connected therewith and the requirements for per-
forming it safely.
Kinetic energy —The energy resulting from a moving object.
Laboratory Safety Standard —A specific hazard communication program for laboratories,
found in 29 CFR 1910.1450. These regulations are essentially a blend of hazard communi-
cation and emergency response for laboratories. The cornerstone of the Laboratory Safety
Standard is the requirement for a written chemical hygiene plan.
Lockout/tagout procedure —An OSHA procedure found in 29 CFR 1910.147. A tag or lock is
used to “tag out” or “log out” a device, so that no one can inadvertently actuate the circuit,
system, or equipment that is temporarily out of service.
Log and Summary of Occupational Injuries and Illnesses (OSHA-300 Log) —A cumulative
record that employers (generally of more than 10 employees) are required to maintain,
showing essential facts of all reportable occupational injuries and illnesses.
Loss —The degradation of a system or component. Loss is best understood when related to
dollars lost. Examples include death or injury to a worker, destruction or impairment of