Basic Calculations for Occupational Safety and Environmental Health Professionals - Mathematics and Statistics for the Environment - page 389

Gas —A state of matter in which the material has very low density and viscosity, can expand
and contract greatly in response to changes in temperature and pressure, easily diffuses
into other gases, and readily and uniformly distributes itself throughout any container.
Ground-fault circuit interrupter (GFCI) —A sensitive device intended for shock protection,
which functions to de-energize an electrical circuit or portion thereof within a fraction of
a second, in case of leakage to ground of current sufficient to be dangerous to persons but
less than that required to operate the overcurrent protective device of the circuit.
Grounded system —A system of conductors in which at least one conductor or point is inten-
tionally grounded, either solidly or through a current-limiting (current transformer) device.
Hazard —The potential for an activity, condition, circumstance, or changing conditions or
circumstances to produce harmful effects. Also an unsafe condition.
Hazard analysis —A systematic process for identifying hazards and recommending correc-
tive action.
Hazard and operability (HAZOP) analysis —A systematic method in which process hazards
and potential operating problems are identified using a series of guide words to investigate
process deviations.
Hazard assessment —A qualitative evaluation of potential hazards in the interrelationships
between and among the elements of a system, upon the basis of which the occurrence prob-
ability of each identified hazard is rated.
Hazard Communication Standard (HAZCOM) —An OSHA workplace standard found in 29
CFR 1910.1200 that requires all employers to become aware of the chemical hazards in
their workplace and relay that information to their employees. In addition, a contractor
conducting work at a client's site must provide chemical information to the client regarding
the chemicals that are brought onto the work site.
Hazard control —A means of reducing the risk from exposure to a hazard.
Hazard identiication —The pinpointing of material, system, process, and plant character-
istics that can produce undesirable consequences through the occurrence of an accident.
Hazardous material —Any material possessing a relatively high potential for harmful effects
upon persons.
Hazardous substance —Any substance that has the potential for causing injury by reason of
its being explosive, flammable, toxic, corrosive, oxidizing, irritating, or otherwise harmful
to personnel.
Hazardous waste —A solid, liquid, or gaseous waste that may cause or significantly contrib-
ute to serious illness or death, or that poses a substantial threat to human health or the
environment when the waste is improperly managed.
Hearing conservation —The prevention of, or minimizing of noise-induced deafness through
the use of hearing protection devices, the control of noise through engineering controls,
annual audiometric tests, and employee training.
Heat cramps —A type of heat stress (a possible side-effect of dehydration) that occurs as a
result of salt and potassium depletion.
Heat exhaustion —A condition usually caused by loss of body water from exposure to excess
heat. Symptoms include headache, tiredness, nausea, and sometimes fainting.
Heat stroke —A serious disorder resulting from exposure to excess heat. It results from sweat
suppression and increased storage of body heat, characterized by high fever, collapse, and
sometimes convulsions or coma.
Homeland Security —Federal cabinet-level department created to protect the United States
and her citizens as a result of 9/11. The new Department of Homeland Security (DHS)
has three primary missions: prevent terrorist attacks within the United States, reduce
America's vulnerability to terrorism, and minimize the damage from potential attacks and
natural disasters.