The following is an explanation which is provided to help you interpret
the information found on manufacturers’ MSDSs. While the format
of these data sheets varies from manufacturer to manufacturer, certain
components appear on each sheet.
Product Identification (top)
This section gives the name and address of the manufacturer and an
emergency phone number where questions about toxicity and chemical
hazards can be directed.
Product Name: Commercial or marketing name.
Synonym: Approved chemical name and/or synonyms.
Chemical Family: Group of chemicals with related physical and chemical properties.
Formula: Chemical formula, if applicable;
i.e., the conventional scientific definition for a material. CAS Number:
Number assigned to chemicals or materials
by the Chemical Abstracts Service.
Hazardous Ingredients Of Mixtures (top)
This section describes the percent composition of the substance, listing
chemicals present in the mixture. If it was tested as a mixture, lists
chemicals which
contribute to its hazardous nature. Otherwise, lists ingredients making up
more than 1% and all carcinogens.
The OSHA
permissible exposure limit (PEL), National
Institute for Occupational Safety and Health (NIOSH) recommended
exposure limit (REL), and/or the American
Conference of Governmental Industrial Hygienists (ACGIH) threshold
limit value (TLV) will also be listed, if appropriate.
The OSHA PEL is the regulated standard, while the others are recommended
limits. The PEL is usually expressed in parts per million parts of
air (ppm) or milligrams of dust or vapor per cubic meter of air (mg/m3).
It is usually a time weighted
average (TWA) - concentration averaged over an eight hour day. Sometimes,
a STEL or short term exposure limit may
be listed. The STEL is a 15 minute TWA which should not be exceeded. A
ceiling limit (c), is a
concentration which may not be exceeded at any time. A skin
notation means that skin exposure is significant in contributing
to the overall exposure.
Physical Data (top)
This section outlines the physical properties of the material. The
information may be used to determine conditions for exposure. For example,
one can determine whether or not a chemical will form a vapor (vapor
pressure), whether this
vapor will rise or fall (vapor density), and what the vapor should smell
like (appearance and odor). This could help determine whether to use
a fume hood or where to place ventilators. The following information
is usually included:
Boiling Point: temperature at which liquid changes to vapor state
Melting Point: temperature at which a solid begins to change to liquid
Vapor Pressure: a measure of how volatile
a substance is and how quickly it evaporates. For comparison, the
VP of water (at 20o C) is 17.5 mm Hg, Vaseline (non-volatile) is
close to 0 mm Hg, and diethyl ether (very volatile) is 440
mm Hg.
Vapor Density (air=1): weight of a gas or
vapor compared to weight of an equal volume of air. Density greater than
1 indicates it is heavier than air, less
than 1 indicates it is lighter than air. Vapors heavier than air can
flow along just above ground, where they may pose a fire or explosion
hazard.
Specific Gravity(water=1): ratio of volume
weight of material to equal volume weight of water. Solubility
in Water: percentage of
material that will
dissolve in water, usually
at ambient temperature. Since the much of the human body is made
of water, water soluble substances more readily absorb and distribute.
Appearance/Odor: color, physical state
at room temperature, size of particles, consistency, odor, as
compared to common substances.
Odor
threshold refers
to the concentration required in the air before vapors are detected
or recognized.
% Volatile by Volume: Percentage of
a liquid or solid, by volume, that evaporates at a temperature
of 70oF.
Evaporation Rate: usually expressed
as a time ratio with ethyl ether = 1, unless otherwise specified.
Viscosity: internal resistance to
flow exhibited by a fluid, normally measured in centiStoke time
or Saybolt
Universal Secs.
Other Pertinent Physical Data: information
such as freezing point is given, as appropriate.
Fire And Explosion Hazard Data (top)
This section includes information regarding the flammability of the material
and information for fighting fires involving the material.
Flashpoint: the lowest temperature at which a liquid gives off enough vapor
to ignite when a source of ignition is present.
Autoignition Temperature: the approximate temperature at which a flammable
gas-air mixture will ignite without spark or flame. Vapors and gases
will spontaneously ignite at lower temperatures in oxygen than in air.
Flammable Limits: the lower explosive limit (LEL) and upper explosive
limit (UEL) define the range of concentration of a gas or vapor in air
at which combustion can occur. For instance, an automobile carburetor
controls this mixture - too
lean (not enough chemical) or too rich (not enough air, as when you flood
your engine), will not ignite.
Extinguishing Media: appropriate extinguishing agent(s) for the material.
Fire-fighting Procedures: Appropriate equipment and methods are indicated for
limiting hazards encountered in fire situations.
Fire or Explosion Hazards: Hazards and/or conditions which may cause fire or
explosions are defined.
Health Hazard Data (top)
This section defines the medical signs and symptoms that may be encountered
with normal exposure or overexposure to this material or its components.
Information on the toxicity of the substance may also be presented.
Results of animal studies are most often given. i.e. LD50 (mouse)=250
mg/kg. Usually expressed in weight of chemical per kg of body weight. LD50 or lethal
dose 50 is the dose of a substance which will cause
the death of half the experimental animals. LC50 is the concentration of the substance in air which will cause the death of
half the experimental animals.
Health hazard information may also distinguish the effects of acute (short
term) and chronic (long-term) exposure.
Emergency And First Aid Procedures
Based on the toxicity of the product, degree of exposure and route
of contact (eye, skin, inhalation, ingestion, injection), emergency
and first aid procedures
are recommended in this section. Additional cautionary statements, i.e.,
Note to Physician, for first aid procedures, when necessary, will
also appear
here.
Reactivity Data (top)
This section includes information regarding the stability of the material
and any special storage or use considerations.
Stability: "unstable" indicates
that a chemical may decompose spontaneously under normal temperatures,
pressures, and mechanical
shocks. Rapid decomposition produces heat and may cause fire or explosion.
Conditions to avoid are listed in this section.
Incompatibility: certain chemicals, when mixed may create hazardous conditions.
Incompatible chemicals should not be stored together.
Hazardous Decomposition Products: chemical substances which may be created
when the chemical decomposes or burns.
Hazardous Polymerization: rapid polymerization may produce enough heat to cause
containers to explode. Conditions to avoid are listed in this section.
Spill, Leak And Disposal Procedures (top)
This section outlines general procedures, precautions and methods
for cleanup of spills. Appropriate waste disposal methods are provided
for safety and environmental protection.
Personal Protection Information (top)
This section includes general information about appropriate personal
protective equipment for handling this material. Many times, this section
of the MSDS
is written for large scale use of the material. Appropriate personal protection
may be determined by considering the amount of the material being used
and the actual manipulations to be performed.
Eye Protection: recommendations are dependent upon the irritancy, corrosivity,
and special handling procedures.
Skin Protection: describes the particular
types of protective garments and appropriate glove materials to provide
personnel protection.
Respiratory Protection: appropriate respirators for conditions exceeding the
recommended occupational exposure limits.
Ventilation: air flow schemes (general, local) are listed to limit hazardous
substances in the atmosphere.
