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Glossary of Common MSDS Terms

Page Updated October 2008

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N

n-:

Normal.Used as a prefix in chemical names signifying a straight-chain structure.

NARCOSIS:

Stupor or unconsciousness produced by narcotics or other materials.

NAUSEA:

Tendency to vomit, a feeling of sickness at the stomach.

NECROSIS:

Localized death of tissue.

NEOPLASM:

New or abnormal tissue growth that is uncontrollable and progressive.

NEPHROTOXIC:

Poisonous to the kidney.

NEURITIS:

Inflammation of the nerves.

NEUTRALIZE:

To render chemically harmless; to return the ph to the neutral level of 7.

NON-FLAMMABLE:

Incapable of being easily ignited or burning with extreme rapidity when lighted. Also, a DOT hazard class for any compressed gas other than a flammable one.

NOx:

A general formula for oxides of nitrogen (NO,NO2). They react with moisture in the respiratory tract to produce acids that corrode and irritate tissue, causing congestion and pulmonary edema. Symptoms of acute exposure can develop over 6 to 24 hours. Chronic exposure to low levels can cause irritation, cough, headache, and tooth corrosion. Exposure to 5 to 50 ppm of NO2 can cause slowly evolving pulmonary edema. Commonly produced by combustion processes, including motor vehicle engines.

NUISANCE PARTICULATES:

Dusts that do not produce significant organic disease or toxic effect from "reasonable" concentrations and exposures.

NYSTAGMUS:

Spastic, involuntary motion of the eyeballs.

O 

ODOR:

Description of the smell of the substance.

ODOR THRESHOLD:

Lowest concentration of a substance's vapor, in air, that can be smelled.

OLFACTORY:

Relating to the sense of smell.

OLIGURIA:

Scanty or low volume of urine.

OPAQUE:

Impervious to light rays.

OPEN TRANSFER:

Any transfer that at any time involves contact of a moving fluid with the atmosphere, air, or oxygen. Open transfer of flammable liquids, especially Class IA liquids, is dangerous due to the release of flammable vapors into the work area. Since there is a risk of fire or explosion if an ignition source is present, do these transfers only in a hood.

ORAL:

Used in or taken into the body through the mouth.

ORAL TOXICITY:

Ratings corresponding to the following definitions are derived from data obtained from the test methods and categories of toxicity as described in 16 CFR 1500.3.

1. NON TOXIC:
   The probable lethal dose of undiluted product to 50% of the test animals determined from ingestion studies (LD50) is greater than 5 grams per kilogram of body weight.
2. TOXIC:
   The probable lethal dose of undiluted product to 50% of the test animals determined from ingestion studies (LD50) is greater than 50 milligrams and less than or equal to 5 grams per kilogram of body weight.
3. HIGHLY TOXIC:
   The probable lethal dose of undiluted product to 50% of the test animals determined from ingestion studies (LD50) is less than or equal to 50 milligrams per kilogram of body weight.

ORGANIC MATERIALS:

Compounds composed of carbon, hydrogen, and other elements with chain or ring structures.

OVEREXPOSURE:

Exposure to a hazardous material beyond the allowable exposure levels.

OXIDATION:

Reaction in which a substance combines with oxygen provided by an oxidizer or oxidizing agent. An oxidation reaction is always accompanied by an offsetting reduction reaction in which (1) oxygen is removed from a compound; or (2) atoms, molecules, or ions gain electrons.

OXIDE POX:

Dermatitis caused by contact with oxides under poor personal hygienic conditions.

OXIDIZER:

Substance that yields oxygen readily to stimulate the combustion of organic matter.

OXIDIZING AGENT:

Chemical or substance that brings about an oxidation reaction.

P 

PALPITATION:

Irregular, rapid heartbeat.

PARATHESIA:

Sensation of pricking, tinkling, or creeping on the skin that has no objective cause.

PARTICULATE:

Small, separate pieces of an airborne material. Generally, anything that is not a fiber and has an aspect ratio of 3 to 1.

PARTS PER MILLION (PPM):

Unit for measuring concentration of a gas or vapor in air. Parts of the gas or vapor in a million parts of air. Also used to indicate the concentration of a particular substance in a liquid or solid.

PERCENT VOLATILE:

Percent volatile by volume is the percentage of a liquid or solid (by volume) that will evaporate at an ambient temperature of 70 degrees F (unless some other temperature is specified). Examples: butane, gasoline, and paint thinner (mineral spirits) are 100 percent volatile; their individual evaporation rates vary, but in time, each will evaporate completely.

PERMISSIBLE EXPOSURE LIMIT (PEL):

Legally enforced exposure limit for a substance established by OSHA. The PEL indicates the permissible concentration of air contaminants to which nearly all workers may be repeatedly exposed 8 hours a day, 40 hours a week, over a working lifetime (40 years), without adverse effects.

PERSONAL HYGIENE:

Precautionary measures taken to maintain good health when exposed to harmful materials.

PERSONAL PROTECTIVE EQUIPMENT (PPE):

Devices or clothing worn to help isolate a worker from direct exposure to hazardous materials.

PETROLEUM DISTILLATE:

Complex mixture of hydrocarbons, liquid at normal ambient conditions, separated from crude oil and other refinery process streams by distillation.

pH:

Scale of 0 to 14 representing acidity or alkalinity of aqueous solution. Pure water has pH of 7. Substance in aqueous solution will ionize to various extent giving different concentrations of H+ and OH- ions.

PHLEGM:

Thick mucous from the respiratory passage.

PHOTOPHOBIA:

Intolerance to light.

PHYSICAL HAZARD:

Means a chemical for which there is scientifically valid evidence that it is a combustible liquid, a compressed gas, explosive, flammable, an organic peroxide, an oxidizer, pyrophoric, unstable (reactive) or water reactive.

PHYSICAL STATE:

Condition of a material (solid, liquid, or gas) at room temperature.

POISON:

Any substance that is injurious to health and may lead to death when relatively small amounts are taken either internally or externally.

PRODUCT IDENTIFICATION NUMBER:

Four-digit number, prefaced by UN or NA, used in Canada under the Transportation of Dangerous Goods Regulation for use by emergency personnel to identify a material in the event of an accident.

PNEUMOCONIOSIS:

Respiratory tract and lung condition caused by inhalation and retention of irritant mineral or metallic particles. An X-ray can detect changes, which include fibrosis.

POISON, CLASS A:

DOT term for an extremely dangerous poison such as a poisonous gas or liquid of such a nature that a very small amount of the gas or vapor of the liquid mixed with air is dangerous to life.

POISON, CLASS B:

Term for liquid, solid, paste, or semisolid substances other than class A poisons or irritating materials known or presumed by animal tests to be so toxic to man to be a health hazard during transportation.

POISON CONTROL CENTER:

Provides medical information on a 24-hour basis for accidents involving ingestion of potentially poisonous materials.

POLYCHLORINATED BIPHENYL (PCB):

Pathogenic and teratogenic compound used as a heat transfer medium. It accumulates in tissue.

POLYMERIZATION:

Chemical reaction in which one or more small molecules combine to form larger molecules. A hazardous polymerization is such a reaction that takes place at a rate that releases large amounts of energy that can cause fires or explosions or burst containers. Materials that can polymerize usually contain inhibitors that can delay the reaction.

POUR POINT:

Temperature at which a liquid ceases or begins to flow or at which it congeals.

POx:

A general term for the several oxides of phosphorus.

PPE:

Personal protective equipment. Devices or clothing worn to help insulate a worker from direct exposure to hazardous materials. Examples include gloves and respirators.

PRECORDIAL:

In front of the heart, stomach.

PRIMARY SKIN IRRITANT:

A non-corrosive substance which produces severe skin irritation.

PRODUCE:

To manufacture, process, formulate, or repackage.

PROSTRATION:

Physical exhaustion, incapacitation.

PROTEINURIA:

Presence of protein in the urine.

psia:

Pounds per square inch absolute.

psig:

Pounds per square inch gauge (i.e., above atmospheric pressure).

PSYCHOTROPIC:

Acting on the mind.

PULMONARY EDEMA:

Fluid in the lungs.

PYOLYSIS:

Chemical decomposition or breaking apart of molecules produced by heating.

PYROPHORIC:

Materials that ignite spontaneously in air below 130 degrees F. Occasionally friction will ignite them.

R 

REACTION:

Chemical transformation or change; interaction of two or more substances to form new substance.

REACTIVE MATERIAL:

Chemical substance or mixture that will vigorously polymerize, decompose, condense, or become self-reactive due to shock, pressure, or temperature. Includes explosive materials, organic peroxides, pressure-generating materials, and water-reactive materials.

REACTIVITY:

Tendency of a substance to undergo chemical reaction with the release of energy.

REAGENT:

Substance used in a chemical reaction to produce another substance or to detect its composition.

RECOMMENDED EXPOSURE LIMIT:

The highest allowable airborne concentration that is not expected to injure a worker. Expressed as a ceiling limit or as a time weighted average, usually for 10-hour work shift.

REDUCING AGENT:

Substance that (1) combines with oxygen or (2) loses electrons to the reaction during a reduction reaction.

REGISTRY OF TOXIC EFFECTS OF CHEMICAL SUBSTANCES:

Published by NIOSH. Presents basic toxicity data on thousands of materials. Objective is to identify "all known toxic substances" and to reference original studies.

RENAL:

Pertaining to the kidney.

REPORTABLE QUANTITY (RQ):

Amount of material that when spilled must be reported to the Federal, State, and local authorities under CERCLA, EPCRA, and the CWA.

REPRODUCTIVE HEALTH HAZARD:

Any agent that has a harmful effect on the adult male or female reproductive system or the developing fetus or child.

RESPIRATORY SYSTEM:

Breathing system, including the lungs and air passages, as well as the associated system of nerves and circulatory supply.

RESPIRATORY PROTECTION:

Devices that will protect the wearer's respiratory system from overexposure by inhalation to airborne contaminants. Respiratory protection is used when a worker must work in an area where he/she might be exposed to concentration in excess of the allowable exposure limit.

RESPONSIBLE PARTY:

Someone who can provide additional information on the hazardous chemical and appropriate emergency procedures, if necessary.

ROUTES OF ENTRY:

Means by which material may gain access to the body (inhalation, ingestion, skin contact).

S 

SAINT ANDREW'S CROSS (X):

Used in packaging for transport; It means harmful--stow away from foodstuffs.

SARCOMA:

A tumor that is often malignant.

SARA:

Superfund Amendments and Reauthorization Act. Signed into law October 17, 1986. Title III of SARA is known as the Emergency Planning and Community Right-to-Know Act of 1986. A revision and extension of CERCLA, SARA is intended to encourage and support local and state emergency planning efforts. It provides citizens and local governments with information about potential chemical hazards in their communities. SARA calls for facilities that store hazardous materials to provide officials and citizens with data on the types (flammables, corrosives, etc.); amounts on hand (daily, yearly); and their specific locations. Facilities are to prepare and submit inventory lists, MSDSs, and tier 1 and 2 inventory forms. The disaster in Bhopal, India in 1987 added impetus to the passage of this law.

SCBA:

Self-contained breathing apparatus.

SCLERAE:

Tough, white, fibrous covering of the eyeball.

SENSITIZATION:

State of immune-response reaction in which further exposure elicits an immune or allergic response. A person previously exposed to a certain material is more sensitive when he experiences further contact with it.

SENSITIZER:

Substance which, on first exposure, causes little or no reaction in man or test animals but which, on repeated exposure, may cause a marked response not necessarily limited to the contact site.

SIDEROSIS:

Pneumoconiosis caused by the inhalation of iron particles. Also, tissue pigmentation caused by contact with iron.

SIGN:

Abnormality in the body indicating poisoning or disease which is observable by another person.

SIGNAL WORDS:

Distinctive words on a MSDS which serves to alert the reader to the existence and relative degree of a hazard. Signal words are limited to:

• Danger:
  Materials that are: highly toxic; corrosive to living tissue; extremely flammable; or are suspected human carcinogens.
• Warning:
  Materials that are: moderately toxic; have severe skin irritation potential; cause allergic skin reactions; or are flammable.
• Caution:
  Materials that: have a low order of toxicity; produce only slight to moderate skin irritation; or are combustible.

SILICOSIS:

Condition of massive fibrosis of the lungs causing shortness of breath because of prolonged inhalation of silica dusts.

SKIN IRRITATION:

Ratings corresponding to the following definitions are derived from data obtained from the test methods as described in the CFR 16 1500.41 and or NAS publication 1138 and categories of toxicity as described in 16 CFR 1500.3.

• PRACTICALLY NON-IRRITATING:
  The undiluted product causes no noticeable irritation or causes slight inflammation (edema and erythema skin reaction values of 0 to 1) of intact or abraded skin of rabbits during the study period. Primary irritation index of 0 - 1.9.
• MODERATELY IRRITATING:
  The undiluted product causes well-defined inflammation (edema and erythema skin reaction values of 2) during the study period. Primary irritation index of 2 - 4.9.
• PRIMARY SKIN IRRITANT:
  The undiluted product cause moderate to severe inflammation (edema and erythema skin reaction values of 3 or 4) of the intact or abraded skin of rabbits during the study period. Primary irritation index of 5 or more.
• CORROSIVE:
  The undiluted product causes visible destruction or irreversible alterations of the tissue structure at the site of contact on intact or abraded skin of rabbits during the study period.

SLURRY:

Pourable mixture of solid and liquid.

SMOKE:

Dry particles and droplets generated by incomplete combustion of an organic material combined with and suspended in the gases from combustion.

SOLUBILITY IN WATER:

Percentage of a material (by weight) that will dissolve in water at ambient temperature.

SOLUTION:

Uniformly dispersed mixture. Composed of a solvent and a dissolved substance, called the solute.

SOLVENT:

Substance, usually liquid, in which other substances are dissolved. Water is the most common solvent.

SOOT:

Fine particles, usually black, formed by combustion consisting chiefly of carbon. Gives smoke color.

SOx:

Oxides of sulfur where x equals the number of oxygen atoms.

SPASM:

Involuntary, convulsive muscular contraction.

SPECIFIC CHEMICAL IDENTITY:

Chemical name, CAS number, or other information that reveals the precise chemical designation of the substance.

SPECIFIC GRAVITY:

>Weight of material compared to equal volume of water: expression of density of material.

STABILITY:

Ability of a material to remain unchanged. A material is stable if it remains in the same form under expected and reasonable conditions of storage or use.

STEL:

Short-term exposure limit.

STEV:

Short-term exposure value.

STOMATITIS:

Inflammation of the mucous membrane of the mouth.

STUPOR:

Partial or nearly complete unconsciousness.

SUBCUTANEOUS:

Beneath the skin.

SUBLIME:

Change from the solid to the vapor phase without passing through the liquid phase.

SYNERGY:

Interaction of materials to give a combined result different from either material alone.

SYNONYM:

Another name or names by which a material is known.

SYSTEMIC EFFECTS:

Acute or chronic adverse health effects which occur in parts of the body removed from the site of exposure to the material.

T 

TACHYCARDIA:

Excessively rapid heartbeat, with a pulse rate above 100.

TACHYPNEA:

Increased rate of respiration.

TARGET ORGAN TOXIN:

Toxic substance that attacks a specific organ of the body.

TERATOGEN:

Substance or agent to which exposure of a pregnant female can result in malformation in the fetus.

THRESHOLD LIMIT VALUE:

Airborne concentration of a material to which nearly all persons can be exposed day after day, without adverse effects. TLV's are expressed in 3 ways:

• TLV-C:
  Ceiling limit, concentration that should not be exceeded even instantaneously.
• TLV-STEL:
  Short term exposure limit, maximum concentration for a continuous 15-minute exposure period.
• TLV-TWA:
  Time-weighted average, concentration for a normal 8-hour work day or 40-hour work week.

THRESHOLD PLANNING QUANTITY (TPQ):

Per 40 CFR 302. The amount of material at a facility that requires emergency planning and notification per CERCLA.

TINNITUS:

Ringing sound in the ears.

TOXICITY:

Sum of adverse effects resulting from exposure to a material, generally by the mouth, skin, or respiratory tract.

TOXICOLOGY:

Study of the nature, effects, and detection of poisons in living organisms. Also, substances that are otherwise harmless but prove toxic under particular conditions.

TOXIC SUBSTANCE:

Chemical or material that (1) has evidence of an acute or chronic health hazard, and (2) is listed in the RTECS manual, provided that the substance causes harm at any dose level; causes cancer or reproductive effects in animals at any dose level; has a median lethal dose level of less than 500 mg per kg of body weight when administered orally to rats; has a median lethal dose level of less than 1000 mg per kg of body weight when administered by continuous contact to the bare skin of albino rabbits; or has a median lethal concentration in air of less than 2000 ppm by volume of gas or vapor, or less than 20 mg per liter of mist, fume, or dust when administered to albino rats.

TOXIC SUBSTANCES CONTROL ACT (TSCA):

Public Law PL 94-469. Found in 40 CFR 700-799. EPA has jurisdiction. Effective January 1, 1977. Controls the exposure to and use of raw industrial chemicals not subject to other laws. Chemicals are to be evaluated prior to use and can be controlled based on risk. The act provides for a listing of all chemicals that are to be evaluated prior to manufacture or use in the US.

TRADE NAME:

Trademark name or commercial trade name for a material given by the manufacturer.

TRADE SECRET:

Any confidential formula pattern, process, device, information, or compilation of information used in an employer's business and gives the employer an opportunity to obtain an advantage over competitors.

TWA:

Time-weighted average exposure is the airborne concentration of a material to which a person is exposed, averaged over the total exposure time, generally the total workday (8 to 12 hours).

U 

UPPER EXPLOSIVE (FLAMMABLE) LIMIT (UEL):

Highest concentration (highest percentage of the substance in air) that will produce a flash of fire when an ignition source (heat, electric arc, or flame) is present.

UNSTABLE:

Tending toward decomposition or other unwanted chemical change during normal handling or storage.

USE:

To package, handle, react, or transfer.

UTRICARIA:

Nettle rash; hives; elevated, itching white patches.

V 

VAPOR:

Gaseous state of a material suspended in air that would be a liquid or solid under ordinary conditions.

VAPOR DENSITY:

Weight of vapor or gas compared to an equal volume of air; expression of the density of the vapor or gas.

VAPOR PRESSURE:

Pressure exerted by a saturated vapor above its liquid in a closed container. Important facts to remember:

• Vapor pressure of a substance at 100° F will always be higher than the vapor pressure of the substance at 60° F.
• Vapor pressures reported on MSDS/s in mmHg are usually very low pressures; 760 mmHg is equivalent to 14.7 psi.
• The lower the boiling point of a substance, the higher its vapor pressure.

VAPOR:

Gaseous form of a solid or liquid substance as it evaporates.

VENTILATION:

Circulating fresh air to replace contaminated air.

VERTIGO:

Feeling of revolving in space; dizziness, giddiness.

VISCOSITY:

Tendency of a fluid to resist internal flow without regard to its density.

VOLATILE ORGANIC COMPOUNDS (VOC):

Used in coatings and paint because they evaporate very rapidly.

VOLATILITY:

Measure of how quickly a substance forms a vapor at ordinary temperatures.

W 

WATER REACTIVE:

Material that reacts with water to release a gas that is either flammable or presents a health hazard.

WORK AREA:

A room or defined space in a workplace where hazardous chemicals are produce or used, and where employees are present.

WORKPLACE:

An establishment at one geographical location containing one or more work areas.

Z 

ZINC FUME FEVER:

Caused by inhalation of zinc oxide fume characterized by flu-like symptoms, a metallic taste in the mouth, coughing, weakness, fatigue, muscular pain, and nausea, followed by fever and chills.

Z LIST:

OSHA's Toxic and Hazardous Substances Tables Z-1, Z-2, and Z-3 of air contaminants, found in 29 CFR 1910.1000. These tables record PEL's, TWA's, and ceiling concentrations for the materials listed. Any material found on these tables is considered to be hazardous.

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