Washington Administrative Code › Title 296 - Labor and Industries, Department of › Chapter 296-841 - Airborne contaminants › Section 296-841-099 - Definitions

Current through Register Vol. 24-14, July 15, 2024
Breathing zone.
The space around and in
				front of an employee's nose and mouth, forming a hemisphere with a
				six to nine inch radius.
Ceiling limit.
See Permissible exposure
				limits (PELs).
Dust.
Solid particles suspended in air.
				Dusts are generated by handling, drilling, crushing, grinding, rapid
				impact, detonation, or decrepitation of organic or inorganic
				materials such as rock, ore, metal, coal, wood, grain, etc.
Exposed or exposure.
The contact an
				employee has with a toxic substance, harmful physical agent or oxygen
				deficient condition, whether or not protection is provided by
				respirators or other personal protective equipment (PPE). Exposure
				can occur through various routes of entry, such as inhalation,
				ingestion, skin contact, or skin absorption.
Fume.
Solid particles suspended in air,
				generated by condensation from the gaseous state, generally after
				volatilization from molten metals, etc.
Gas.
A normally formless fluid which can
				be changed to the liquid or solid state by the effect of increased
				pressure or decreased temperature or both.
General exhaust ventilation.
The general
				movement of air out of an area or permit-required confined space by
				mechanical or natural means.
Immediately dangerous to life or health
				(IDLH).
An atmospheric condition that would:
(a) Cause an immediate threat to life;
(b) Cause permanent or delayed adverse health
				effects; or
(c) Interfere with an employee's ability to escape.
Mist.
Liquid droplets suspended in air, generated by
				condensation from the gaseous to the liquid state or by breaking up a
				liquid into a dispersed state, such as by splashing, foaming,
				spraying or atomizing.
Nuisance dust (or inert dust).
Dusts
				that, when inhaled, have little adverse effect on the lungs
and
do not produce significant organic disease or toxic
				effect when exposures are kept under reasonable control.
The biological reaction to these dusts in lung tissue
				has the following characteristics:
(a) The architecture of the air spaces remains
				intact;
(b) Scar tissue (collagen) is not formed to a
				significant extent; and
(c) The tissue reaction is potentially
				reversible.
Oxygen deficient.
An atmosphere with an
				oxygen content below 19.5% by volume.
Permissible exposure limits (PEL).
The
				amount of an airborne chemical, toxic substance, or other harmful
				agent that must not be exceeded during any part of the
				workday.
An airborne chemical or toxic substance can have 3
				PEL values:
(a) TWA8. This is an 8-hour,
				time-weighted average limit.
(b) Short-term exposure limit (STEL). This is
				typically a 15-minute, time-weighted average limit.
(c) Ceiling limit (C). This is an instantaneous
				limit.
Short-term exposure limit (STEL).
See
				Permissible exposure limits (PELs).
Temper.
To condition air for a specific
				work environment by changing its temperature or moisture
				content.
Time weighted average
				(TWA8).
See Permissible exposure limits
				(PELs).
Toxic substance.
Any chemical substance
				or biological agent, such as bacteria, virus, and fungus, which is
				any of the following:
(a) Listed in the latest edition of the National
				Institute for Occupational Safety and Health (NIOSH) Registry of
				Toxic Effects of Chemical Substances (RTECS).
(b) Shows positive evidence of an acute or chronic
				health hazard in testing conducted by, or known to, the
				employer.
(c) The subject of a safety data sheet kept by or
				known to the employer showing the material may pose a hazard to human
				health.
Vapor.
The gaseous form of a substance
				that is normally in the solid or liquid state.
Ventilation.
Providing, circulating or
				exhausting air into or out of an area or space.