Atomic absorption spectrophotometers
The American Conference of Governmental
Industrial Hygienists is a voluntary organization of professional industrial hygiene
personnel in government or educational institutions. The ACGIH develops and publishes
recommended occupational exposure limits each year called Threshold Limit Values (TLVs)
for hundreds of chemicals, physical agents, and biological exposure indices.
- Action level
A concentration for a specific substance,
calculated as an eight (8) hour time-weighted average, which initiates certain required
activities such as exposure monitoring and medical surveillance. Typically it is one-half
that of the PEL for that substance.
- Acute Exposure
Single exposure episodes which occur over a
short time period.
The American National Standards Institute is
a voluntary membership organization (run with private funding) that develops consensus
standards nationally for a wide variety of devices and procedures.
American Society of Heating, Refrigeration
and Air Conditioning Engineers.
A chemical (gas or vapor) that can cause
death or unconsciousness by suffocation. Simple asphyxiants such as nitrogen, either use
up or displace oxygen in the air. They become especially dangerous in confined or enclosed
spaces. Chemical asphyxiants, such as carbon monoxide and hydrogen sulfide, interfere with
the body's ability to absorb or transport oxygen to the tissues.
- Biohazard Wastes
Discarded materials "that are
biological agents or conditions (as an infectious organism or unsecure laboratory
condition) that constitutes a hazard to man or his environment." This definition
includes "any and all substances which contain materials to which organisms may cause
injury or disease to man or his environment, but which are not regulated as controlled
Biological Safety Committee
Biological Safety Officer
- "C" or Ceiling
A description usually seen in connection
with a published exposure limit. It refers to the concentration that should not be
exceeded, even for an instant. It may be written as TLV-C or Threshold Limit
Value--Ceiling. (See also Threshold Limit Value).
Any substance that causes the development of
cancerous growths in living tissue, either those that are known to induce cancer in man or
animals or experimental carcinogens that have been found to cause cancer in animals under
- C.A.S. Number
Identifies a particular chemical by the
Chemical Abstracts Service, a service of the American Chemical Society that indexes and
compiles abstracts of worldwide chemical literature called "Chemical Abstracts".
These numbers are always contained in brackets.
Centers for Disease Control
Code of Federal Regulations
- Chemical Hygiene Plan
A written program developed and implemented
by the employer which sets forth procedures, equipment, personal protective equipment and
work practices that are capable of protecting employees from the health hazards presented
by hazardous chemicals used in that particular work place and meets the requirements of 29
See Chemical Hygiene Plan
- Chemical Reaction
A change in the arrangement of atoms or
molecules to yield substances of different composition and properties. (See Reactivity).
- Chronic Exposure
A series of exposures occurring over a
longer period of time.
A combustible liquid or an "Ordinary
Combustible" such as wood, paper, etc.
- Combustible Liquid
Any liquid having a flashpoint at or above
100°F (37.8°C), but below 200°F (93.3°C), except any mixture having components with
flashpoints of 200°F (93.3°C), or higher, the total volume of which make up 99 percent
or more of the total volume of the mixture.
Any gas, liquid, or solid that causes
destruction of human tissue or a liquid that has a severe corrosion rate on steel.
Generally, a substance that has a very low or a very high pH.
Pertain to or affecting the skin.
The breakdown of a chemical or substance
into different parts or simpler compounds. Decomposition can occur due to heat, chemical
reaction, decay, etc.
Pertaining to or affecting the skin.
An inflammation of the skin.
- Designated Area
An area which may be used for work with
"select carcinogens, reproductive toxins, or substances which have a high degree of
acute toxicity." A designated area may be the entire laboratory, an area of a
laboratory, or a device such as a laboratory hood. A designated area shall be placarded to
reflect the designated hazard.
The concentration of a substance and the
time period during which the exposure occurs. The dose received links hazard and toxicity.
The United States Department of
Transportation is the federal agency that regulates the labeling and transportation of
Shortness of breath; difficult or labored
- Emergency Spills
Accidental chemical discharges that present
an immediate danger to personnel and/or the environment. Under these circumstances, leave
the spill site immediately and send for help. Management of these spills is the
responsibility of specially trained and equipped personnel. Contact the campus police at
911 for response. They will notify the appropriate persons/departments. (See Section 1.1 -
An individual employed in a laboratory work
place who may be exposed to hazardous materials in the course of his or her assignments.
The Environmental Protection Agency is the
governmental agency responsible for administration of laws to control and/or reduce
pollution of air, water, and land systems.
- EPA Number
The number assigned to chemicals regulated
by the Environmental Protection Agency (EPA).
A reddening of the skin.
- Class A
- Fires in ordinary combustible materials such as wood, cloth,
paper, rubber, and many plastics.
- Class B
- Fires in flammable liquids, oils, greases, tars, oil-base
paints, lacquers and flammable gases.
- Class C
- Fires that involve energized electrical equipment where the
electrical conductivity of the extinguishing medium is of importance; when electrical
equipment is de-energized, extinguishers for class A or B fires may be safely used.
- Class D
- Fires in combustible metals such as potassium, sodium,
lithium, magnesium, titanium, sirconium.
Any substance which may be classified as a
flammable aerosol, flammable gas, flammable liquid or flammable solid.
- Flammable Aerosol
An aerosol that, when tested by the method
described in 16 CFR 1500.45, yields a flame protection exceeding 18 inches at full valve
opening, or a flashback (a flame extending back to the valve) at any degree of valve
- Flammable Gas
A gas that, at ambient temperature and
pressure, forms a flammable mixture with air at a concentration of 13 percent by volume or
less; or a gas that, at ambient temperature and pressure, forms a range of flammable
mixtures with air wider that 12 percent by volume, regardless of the lower limit.
- Flammable Liquid
Any liquid having a flashpoint below 100°F
(37.8°C), except any mixture having components with flashpoints of 100°F (37.8°C), or
higher, the total volume of which make up 99 percent or more of the total volume of the
- Flammable Solid
A solid, other than a blasting agent or
explosive, that is liable to cause fires through friction, absorption of moisture,
spontaneous chemical change, retained heat from processing, or which can be ignited
readily, and when ignited burns so vigorously and persistently as to create a serious
hazard. A chemical shall be considered a flammable solid if, when tested by the method
described in 16 CFR 1500.44, it ignites and burns with a self-sustained flame at a rate
greater than one-tenth of an inch per second along its major axis.
The possibility that exposure to a substance
will cause injury when a specific quantity is used under certain conditions.
- Health Hazard
A substance for which there is statistically
significant evidence based on at least one study conducted in accordance with established
scientific principles that acute or chronic health effects may occur in exposed employees.
This term includes carcinogens, toxic or highly toxic agents, reproductive toxins,
irritants, corrosives, sensitizers, hepatotoxins, nephrotoxins, neurotoxins, agents which
act on the hematopoietic systems, and agents which damage the lungs, skin, eyes, or mucous
Inductively-coupled argon spectrometers
Immediately dangerous to life or health
concentrations represent the maximum concentration from which one could escape within 30
minutes without a respirator and without experiencing any escape-impairing (e.g., severe
eye irritation) or irreversible health effects.
A solid, liquid, or compressed gas that has
a flashpoint of less 140°F. Ignitable material may be regulated by the EPA as a hazardous
waste, as well.
The term applied to two substances to
indicate that one material cannot be mixed with the other without the possibility of a
Taking a substance into the body through the
mouth as food, drink, medicine, or unknowingly as on contaminated hands or cigarettes,
The breathing in of an airborne substance
that may be in the form of gases, fumes, mists, vapors, dusts, or aerosols.
A substance that is added to another to
prevent or slow down an unwanted reaction or change.
A substance that produces an irritating
effect when it contacts skin, eyes, nose, or respiratory system.
See Lethal Concentration50.
See Lethal Dose50.
See Lower Explosive Limit.
- Lethal Concentration50
The concentration of an air contaminant that
will kill 50 percent of the test animals in a group during a single exposure.
- Lethal Dose50
The dose of a substance or chemical that
will kill 50 percent of the test animals in a group within the first 30 days following
See Lower Explosive Limit.
- Lower Explosive Limit
(Also known as Lower Flammable Limit.) The
lowest concentration of a substance that will produce a fire or flash when an ignition
source (flame, spark, etc.) is present. It is expressed in percent of vapor or gas in the
air by volume. Below the LEL or LFL, the air/contaminant mixture is theoretically too
"lean" to burn. (See also UEL.)
Small chemical leaks that usually are
detected early and present no immediate danger to personnel or the environment. These are
spills that can be safely corrected with the advice of knowledgeable laboratory or
Material Safety Data Sheet (See Section 9.3)
Anything that can cause a change (or
mutation) in the genetic material of a living cell.
Stupor or unconsciousness caused by exposure
to a chemical.
The National Fire Protection Association is
a voluntary membership organization whose aims are to promote and improve fire protection
and prevention. NFPA has published several volumes of codes known as the National Fire
National Institute of Health
The National Institute for Occupational
Safety and Health is a federal agency that among its various responsibilities trains
occupational health and safety professionals, conducts research on health and safety
concerns, and test and certifies respirators for work place use.
The minimum concentration of a substance in
the air at which a majority of test subjects can detect and identify the substance's
The Occupational and Safety Health
Administration is a federal or state agency under the Department of Labor that publishes
and enforces safety and health regulations for most businesses and industries in the
- OSU HAZCOMM
OSU Environmental Health Services Department
Hazard Communications Section
- OSU HAZMAT
OSU Environmental Health Services Department
Hazardous Materials Section
A substance such as chlorate, permanganate,
inorganic peroxide, nitrocarbonitrate, or a nitrate that yields oxygen readily to
stimulate the combustion of organic matter.
- Oxygen Deficiency
An atmosphere having less than the normal
percentage of oxygen found in normal air. Normal air contains approximately 21% oxygen at
See Permissible Exposure Limit.
- Permissible Exposure Limit
An exposure limit that is published and
enforced by OSHA as a legal standard. PEL may be either a time-weighted-average (TWA)
exposure limit (8 hour), a 15-minute short term exposure limit (STEL), or a ceiling (C).
The PELs are found in Tables Z-1, Z-2, or Z-3 of 29 CFR 1910.100. This level of exposure
is deemed to be the maximum safe concentration and is generally the same value as the
threshold limit value (TLV).
- Personal Protective Equipment
Any devices or clothing worn by the worker
to protect against hazards in the environment. Examples are respirators, gloves, and
chemical splash goggles.
- Physical Hazard
A substance which is a compressed gas,
explosive, flammable, organic peroxide, oxidizer, pyrophoric, unstable or water reactive.
A chemical reaction in which two or more
small molecules combine to form larger molecules that contain repeating structural units
of the original molecules. A hazardous polymerization is the above reaction with an
uncontrolled release of energy.
A substance's susceptibility to undergoing a
chemical reaction or change that may result in dangerous side effects, such as explosion,
burning, and corrosive or toxic emissions. The conditions that cause the reaction, such as
heat, other chemicals, and dropping, will usually be specified as "Conditions to
Avoid" when a chemical's reactivity is discussed on a MSDS.
A device which is designed to protect the
wearer from inhaling harmful contaminants.
- Respiratory Hazard
A particular concentration of an airborne
contaminant that, when it enters the body by way of the respiratory system or by being
breathed into the lungs, results in some bodily function impairment.
A substance that may cause no reaction in a
person during initial exposures, but afterwards, further exposures will cause an allergic
response to the substance.
Hypodermic needles, syringes, (with or
without the attached needle), pasteur pipettes, scalpel blades, suture needles, blood
vials, needles with attached tubing, and culture dishes (regardless of presence of
infectious agents). Also included are other types of broken or unbroken glassware that
were in contact with infectious agents, such as used slides and cover slips.
- Short Term Exposure Limit
Represented as STEL or TLV-STEL, this is the
maximum concentration to which workers can be exposed for a short period of time (15
minutes) for only four times throughout the day with at least one hour between exposures.
This designation sometimes appears alongside
a TLV or PEL. It refers to the possibility of absorption of the particular chemical
through the skin and eyes. Thus, protection of large surface areas of skin should be
considered to prevent skin absorption so that the TLV is not invalidated.
See Short Term Exposure Limit
Another name by which the same chemical may
Spread throughout the body; affecting many
or all body systems or organs; not localized in one spot or area.
An agent or substance that may cause
physical defects in the developing embryo or fetus when a pregnant female is exposed to
- Threshold Limit Value
Airborne concentrations of substances
devised by the ACGIH that represents conditions under which it is believed that nearly all
workers may be exposed day after day with no adverse effect. TLVs are advisory exposure
guidelines, not legal standards, that are based on evidence from industrial experience,
animal studies, or human studies when they exist. There are three different types of
TLV's: Time Weighted Average (TLV-TWA), Short Term Exposure Limit (TLV-STEL) and Ceiling
(TLV-C). (See also PEL.)
- Time Weighted Average
(TLV-TWA, Threshold Limit Value-Time
Weighted Average) The time weighted average airborne chemical concentration for a normal
eight hour work day and a 40 hour work week to which nearly all workers may be repeatedly
exposed, day after day, without adverse effect.
See Threshold Limit Value.
Substances such as carcinogens, irritants,
or poisonous gases, liquids, and solids which are irritating to or affect the health of
The potential of a substance to exert a
harmful effect on humans or animals and a description of the effect and the conditions or
concentrations under which the effect takes place.
- Trade Name
The commercial name or trademark by which a
chemical is known. One chemical may have a variety of trade names depending on the
manufacturers or distributors involved.
- TWASee Time Weighted Average.
See Upper Explosive Limit.
See Upper Explosive Limit.
- Unstable Liquid
A liquid that, in its pure state or as
commercially produced, will react vigorously in some hazardous way under shock conditions
(i.e., dropping), certain temperatures, or pressures.
- Upper Explosive Limit
Also known as Upper Flammable Limit. Is the
highest concentration (expressed in percent of vapor or gas in the air by volume) of a
substance that will burn or explode when an ignition source is present. Theoretically
above this limit the mixture is said to be too "rich" to support combustion. The
difference between the LEL and the UEL constitutes the flammable range or explosive range
of a substance. (See also LEL.)
The gaseous form of substances which are
normally in the liquid or solid state (at normal room temperature and pressure).
- Water Reactive
Substances that react violently when in
contact with water. They can be either be flammable solids or corrosives.