Materials and Safety Data Sheets
Terms and Definitions
Identification:
Chemical Name
A group of single elements or compounds with a common name. Example; acetone, methylethyl
ketone (MEK), and methyl isobutyl ketone (MIBK) are of the "Ketone" family;
acrolein, furfural, and acetaldehyde are of the "aldehyde" family.
C.A.S, Number
Chemical Abstracts Service. A Columbus, Ohio organization which indexes information
published in "Chemical Abstracts" by the American Chemical Society, and provides
index guides by which information about particular substances may be located in the
"Abstracts" when needed. "C.A.S. Numbers" identify specific chemicals.
Flammablity
OSHA, Occupational Safety & Health Administration, and NFPA, National Fire Protection
Association define flammable liquids as any liquid with a flash point below 100 degree F.
The lowest temperature at which a liquid gives off sufficient vapor to form an ignitable
mixture with air is called the _ flashpoint. In a flammable liquids fire, it is the vapors
from the liquid that ignite. Vapor pressure is the pressure exerted by the evaporation of
vapor above the surface of a liquid in a closed container. The vapor pressure of a liquid
increases with temperature, also see combustible *** FLAMMABLE LIQUIDS, called Class 1
Liquids, are divided into three groups-- Class A,B, and C--according to the degree of the
hazard, Liquids with flash points above 11 degrees F are called combustible. _ ***OSHA
permits storage of up to 60 gallons of Class 1 or Class II liquids and up to 120 gallons
of Class III liquids in safety cabinets near works stations. Classification of Flammable
and Combustible Liquids
Class Flashpoint, Degrees F Boiling Point, Degrees F
IA below 73 below 100
IB below 73 above 100
IC at least 73, but below 100
II at least 100, but below 140
IIIA at least 140, but below 200
IIIB 200 and above
Reactivity
A discription of the tendency of a substance to undergo chemical reaction (usually with
the release of energy). Undesirable effects such as pressure buildup; temperature
increase; formation of noxiuos, toxic, or corrosive by-products; may occur because of the
reactivity of a substance by heating, burning, direct contact with other materials, or
other coinditions of use or storage. A solid waste which exhibits a "characteristic
of reactivity," as defined by RCRA, may be regukated (EPA) as a hazardous waste.
Fire, Explosion & Reactivity:
Flash Point
The lowest temperature at which the material will flash or ignite when exposed to flame.
Stated another way, it is the lowest temperature at which a liquid will produce sufficient
vapor to burn. The flash points may vary for the same material depending on the method
used, so the test method is indicated when the flash point is given. There are four
accepted methods of testing flash point. The Tag Closed Cup (TCC or CC) is normally the
preferred method. However, the Tag Open Cup (TOC), Cleveland Open Cup (COC) and
Pensky-Martens (PM) methods are also widely used to test flash point.
D.O.T
U.S. Department of Transportation. Regulates transportation of chemicals and other
substances for the protection of the public; law enforcement, and emergency response
personnel, particularly when transportation incidents occur involoving hazardous
materials. Detailed DOT classification lists specify appropriate warning labels-such as
Oxiding Agent or Flammable Liquid-which must be used for various substances during
transport .
Stability
An expression of the ability of a material to remain unchanged. For MSDS purposes, a
material is stable if it remains in the same form under expected and reasonable conditions
of storage or use. Examples of conditions which may cause instability (dangerous change)
are: temperatures above 150 F shock from dropping, combination with another chemical.
NFPA Classification
National Fire Protection Assn. An international volutary membership organization to
promote/improve fire protection and provention, and establish safeguards against loss of
life and property by fire. Best known on the industrial scene for the National Fire Codes-
16 volumes of codes, standards, recommended practices, and manuals developed and updated
by NFPA technical committees. Among these is NFPA 704M, the code for showing hazards of
materials using the familiar diamond-shaped label or placard with appropriate numbers or
symbols. The brief expalnation below illustrates the NFPA principle of using scales of 0
to 4 (low to high) to classify material hazards.
Hazardous Combustible Decomposition Products
A term used by the National Fire Protection Assn. DOT, and others to classify certain
liquids that will not burn, on the basis of flash points. In the hazard communication
rules, a combustible liquid has a flash point at or above 100 F (37.8 C), BUT BELOW 200 F.
Also, see combustible liquid in 1910.1200(C).
Hazardous Polymerization Products
A chemical reation in which one or more small compounds. A hazardous poolymerization is
such a reation which takes place at rate which releases large amounts of enery (usually
heat). If hazardous polymerization can ooccur with a given material, the MSDS usually will
list conditions which could start the reaction; and since the material usually contains a
polymerization inhibitor, the expected time period before the inhibitor is used up should
be stated.
Physical Data:
Boiling Point
The temperature ar which a liquid changes to a vapor state, at given pressure; usually
expressed on degrees Fahrenheit at sea level pressure (760 mmHg, or one atmosphere). For
mixtures, the initial boiling point or the boiling range may be given. Flammable materials
with low boiling points generally present extreme fire hazards. Some approxiate boiling
points: Propane 44 F , Anhydruos Ammonia 28 F , Butane 31 F , Gasoline 100 F , Allyl
Chloride 113 F , Ethylene Glycol 387 F .
Specific Gravity
The weight of the material compared to the weight of an equal volume of water; an
expression of the density (or heaviness) of the material. Example; if a volume of a
material weighs eight pounds, and equal volume of water weights ten pounds, the material
is said to have a specific gravity of 0.8 8lbs= 10lbs =0.8 Insoluble materials with
specific gravity of less than 1.0 will float in (or on) water. Most (butnot all) flammable
liquids have specific gravities less than 1.0 and, if not soluble, will float on water, an
important consideration for fire suppression and spill clean-up.
Melting Point
The temperature at which a solid substance changes to a liquid state. For mixtures, the
melting range may be given.
Vapor Pressure
The pressure exerted by the vaporization of a liquid in a closed container. When vapor
pressure tests are proformed on products the test temperature is usually 68-100 F, and the
vapor pressure is expressed as pounds per square inch. Vapor pressures reported on MSDS
are in millmeters of mercury at 68 F (20 C), unless stated otherwise. Three facts are
important to remember:
Vapor pressure of a substance at 100 F will always be higher than the vapor pressure of
the substance at 68 F (20 C).
Vapor pressures reported on MSDS in mmHg are usually very low pressures; 760 mmHg is
equivalent to 14.7 pounds per square inch.
The lower the boiling point of a substance, the higher its vapor pressure.
Vapor Density
The weight of vapor or gas compared to the weight of an equal volume of air; an expression
of the density of the vapor or gas. Materials lighter than air have vapor densities less
than 1.0. Materials heavier than air (examples: carbon dioxide, propane, hydrogen sulfide,
ethane, butane, chlorine, sulfur dioxide) have vapor densities greater than 1.0. All
vapors and gases will mix with air, but the lighter materials will tend to rise. Heavier
vapors and gases are likely to concentrate in low places (along or under floors, in sumps,
sewers and manholes, in trenches and ditches) where they may create fire or health
hazards.