b No data is available on the resistance to dimethyl sulfoxide of neoprene, nitrile, or vinyl materials; the manufacturer recommends using butyl rubber gloves.

Chemicals in columns A and B should be kept separate. These examples are illus-trative of common laboratory chemicals; this list is not intended to be exhaustive.

A B

Acetylene and monosubstituted Group IB and IIB metals and

acetylenes (RC=CH) their salts

Halogens

Acids Bases

Alkali and alkaline earth metals Water

carbides Acids

hydrides Halogenated organic hydroxides compounds

oxides Oxidizing agents*

peroxides Chromates, dichromates Halogens

Halogenating agents

Hydrogen peroxide and peroxides

Nitric acid, nitrates

Perchlorates and chlorates

Permanganates

Persulfates

Ammonia, anhydrous and aqueous Halogens

Halogenating agents

Silver Mercury

Inorganic azides Acids

Heavy metals and their salts

Oxidizing agents*

*Oxidizing agents include the types of compounds listed in the entry for alkali and alkaline earth metals, etc.

Inorganic cyanides Acids

Strong bases

Inorganic nitrates Acids

Metals

Nitrites

Sulfur

Inorganic nitrites Acids

Oxidizing agents*

Inorganic sulfides Acids

Mercury and its amalgams Acetylene

Ammonia, anhydrous and aqueous

Nitric acid

Sodium azide

Nitric acid Chromic acid and chromates

Metals

Nitrites, reducing agents

Permanganates

Sulfides

Sulfuric acid

Organic compounds Oxidizing agents*

organic acyl halides Bases

Organic hydroxy compounds

organic anhydrides Bases

Organic hydroxy compounds

organic halogen compounds Aluminum metal

organic nitro compounds Strong bases

Oxalic acid Mercury and its salts

Silver and its salts

*Oxidizing agents include the types of compounds listed in the entry for alkali and alkaline earth metals, etc.

Phosphorus (yellow) Oxygen

Oxidizing agents* Strong bases

Phosphorus pentoxide Halogenating agents

Water

Powdered metals Acids

Oxidizing agents*

Sulfuric acid Metals

Chlorates Perchlorates

Permanganates

Nitric acid

*Oxidizing agents include the types of compounds listed in the entry for alkali and alkaline earth metals, etc.

ACGIH. Threshold Limit Values for Chemical Substances and Physical Agents and Biological Exposure Indices. Cincinnati, Ohio: ACGIH; 1995.

American Chemical Society. Safety in Academic Chemistry Laboratories. 6th ed. Washington, DC; 1995.

Bretherick, L. Handbook of Reactive Chemical Hazards. 5th ed. Oxford, Boston: Butterworth-Heineman; 1995.

CDC/NIH. Biosafety in Microbiological and Biomedical Laboratories. 3rd ed. Washington DC;1993.

Dux, J.P., Stalzer, R.F. Managing Safety in the Chemical Laboratory. New York, New York: Van Nostrand Reinhold; 1988.

Furr, A.K. CRC Handbook of Laboratory Safety. 4th ed. Boca Raton, Florida: CRC Press; 1990.

Klaasen, C.D., Amdur, M, Doull, J., Cassarett and Doull's Toxicology: The Basic Science of Poisons, Third Edition, Macmillan Publishing Company, New York, New York, 1986

Lenga, R.A., The Sigma-Aldrich Library of Chemical Safety Data, Edition II, Volumes I and II, Sigma-Aldrich Corporation, 1988

Lewis, R.J. Sax's Dangerous Properties of Industrial Materials. 8th ed. 3 vols. New York: Van Nostrand Reinhold; 1996.

Lewis, R.J. Hazardous Chemicals Desk Reference. , New York: Van Nostrand Reinhold; 1997.

The Merck Index, Eleventh Edition, 1989

National Research Council. Prudent Practices for Disposal of Chemicals from Laboratories. Washington, DC: National Academy Press; 1983.

National Research Council. Prudent Practices for Handling Hazardous Chemicals in Laboratories. Washington DC: National Academy Press; 1981.

National Institutes for Occupational Safety and Health. Pocket Guide to Chemical Hazards. Washington DC: USDHHS; 1994.

Patty, F. A. Industrial Hygiene and Toxicology. 4th ed. New York: John Wiley and Sons, 1991.

Perrin, D.D., Armarega, W.L.F., Perrin, D.R. Purification of Laboratory Chemicals. 4th ed. New York: Pergamon Press: 1996.

Raffle, P.A.B., Lee, W.R., McCallum, R , Murray, R., Hunter's Diseases of Occupations. 8th ed. London, Boston: E. Arnold; 1994.

Acute Severe, often dangerous conditions in which relatively

rapid changes occur.

Acute Exposure An intense exposure over a relatively short period of time.

Asphyxiant 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 becomes 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.

Boiling Point The temperature at which the vapor pressure of a liquid equals atmospheric pressure or at which the liquid changes to a vapor. The boiling point is usually expressed in degrees Fahrenheit. If a flammable material has a low boiling point, it indicates a special fire hazard.

"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)

Carcinogen A substance or physical agent that may cause cancer in animals or humans.

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."

Chemical As broadly applied to the chemical industry, an element or a compound produced by chemical reactions of a large scale of either direct industrial and consumer use or for reaction with other chemicals.

Chemical Reaction A change in the arrangement of atoms or molecules to yield substances of different composition and properties. (see REACTIVITY)

Chronic Persistent, prolonged, or repeated conditions.

Chronic Exposure A prolonged exposure occurring over a period of days,

weeks, or years.

Combustible Liquid According to the DOT and the NFPA, combustible liquids are those having a flash point at or above 100o F (37.8o C), or liquids that will burn. They do not ignite as easily as flammable liquids. However, combustible liquids can be ignited under certain circumstances, and must be handled with caution.

Concentration The relative amount of a material in combination with another material. For example, 5 parts (of acetone) per million (parts of air).

Corrosive A substance that, according to the DOT, causes visible destruction or permanent changes in human skin tissue at the site of contact or is highly corrosive to steel.

Cubic Meter A measure of volume in the metric system.

Cutaneous Pertaining to, or affecting the skin.

Decomposition The breakdown of a chemical or a substance into different parts of simpler compounds. Decomposition can occur due to wear, chemical reaction, decay, etc.

Dermatitis An inflammation of the skin.

Designated Area An area which may be used for work with "select carcinogens," reproductive toxins, or substances with a high degree of acute toxicity. A designated area may be the entire lab or just a section of it, such as a laboratory hood.

Dilution Ventilation See GENERAL VENTILATION.

Dyspnea Shortness of breath; difficult or labored breathing.

Employee An individual employed in a laboratory workplace who may be exposed to hazardous chemicals in the course of his or her assignments.

Epidemiology The study of disease in (human) population.

Erythema A reddening of the skin.

Evaporation Rate The rate at which a material is converted to vapor (evaporates) at a given temperature and pressure when compared to the evaporation rate of a given substance.

Explosive A chemical that causes a sudden, almost instantaneous release of pressure, gas, or heat when subjected to sudden shock, pressure, or high temperature.

Eye Hazard A chemical which affects the eye or visual capacity.

Signs and symptoms: conjunctivitis, corneal damage; chemicals: organic solvents, acids.

Flammable a) Aerosol, flammable -- an aerosol that, when tested by the method described in 16 CFR 1500.45, yields a flame projection exceeding 18 inches at full valve opening or a flashback (a flame extending back to the valve) at any degree of opening.

b) Gas, flammable --

1) a gas that, at ambient temperature and pressure, forms a flammable mixture with air as a concentration of 13% by volume or less, or

2) a gas that, at ambient temperature and pressure, forms a range of flammable mixtures with air wider than 12% by volume, regardless of flash point below 100o F, except any mixture having components with flash points of 100o F or higher, the total of which make up 99% or more of the total volume of the mixture.

c) Liquid, flammable -- According to the DOT and NFPA, a liquid which has a flash point below 100o F (37.8o C) (see FLASH POINT)

d) Solid, flammable -- a solid, other than a blasting agent or explosive as defined in 1910.109(a), that is liable to cause fire through friction, absorption or moisture, spontaneous chemical change, or retained heat from manufacturing or 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 to be a flammable solid if, when tested by the method described in 16 CFR 1500.45, 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.

Flash Point The lowest temperature at which liquid gives off enough vapor to form an ignitable mixture and burn when a source of ignition (sparks, open flame, cigarettes, etc.) is present. Two tests are used to determine flash point: open cup and closed cup. The appropriate test method is indicated on the MSDS after the flash point.

General Ventilation Also known as general exhaust ventilation. This is a system of ventilation consisting of either natural or mechanically induced fresh air movements to mix with and dilute contaminants in the workroom air. This is not the recommended type of ventilation to control contaminants that are highly toxic, when there may be corrosion problems from the contaminant being generated, and where fire or explosion hazards are generated close to sources of ignition. (see also LOCAL EXHAUST VENTILATION)

Hazardous Material Any substance or compound that has the capability of producing adverse effects on the health and safety of humans.

Hematopioetic Agents which act on the blood or the hematopoietic system. They decrease hemoglobin function and deprive the body tissues of oxygen. Signs and symptoms: cyanosis, loss of consciousness; chemicals: carbon monoxide, cyanides.

Hepatoxins Chemicals which produce liver damage. Signs and symptoms: jaundice, liver enlargement; chemicals: carbon tetrachloride, nitrosamines.

Highly Toxic a) A chemical that has a medial lethal dose (LD50) of 50 milligrams or less per kilogram of body weight when administered orally to albino rats weighing between 200 and 300 grams each.

b) A chemical that has a median lethal dose (LD50) of 200 milligrams or less per kilogram of body weight when administered by continuous contact for 24 hours (or less if death occurs within 24 hours) with the bare skin of albino rabbits weighing between two and three kilograms each

c) A chemical that has a median lethal concentration (LC50) in air of 200 parts per million by volume or less or gas or vapor, or 2 milligrams per liter or less of mist, fume, or dust when administered by continuous inhalations for one hour (or less if death occurs within one hour) to albino rats weighing between 200 and 300 grams each.

Ignitable A solid, liquid, or compressed gas waste that has a flash point of less than 140o F. Ignitable material may be regulated by the EPA as a hazardous waste as well.

Incompatible The term applied to two substances to indicate that one material cannot be mixed with the other without the possibility of a dangerous reaction.

Ingestion Taking a substance into the body through the mouth, as in food, drink, medicine, or unknowingly as on contaminated hands or cigarettes, etc.

Inhalation The breathing in of an airborne substance that may be in the form of gases, fumes, mists, vapors, dust or aerosols.

Inhibitor A substance that is added to another to prevent or slow down an unwanted reaction or change.

Irritant A substance that produces an irritating effect when it contacts skin, eyes, nose or respiratory system.

Kilogram A unit of (kg) weight in the metric system equal to 2.2 pounds.

Lethal Dose 50 The dose of a (LD50) substance or chemical that will kill 50% of the test animals in a group during a single exposure.

Local Exhaust Also known as exhaust ventilation. A ventilation Ventilation system that captures and removes the contaminants at the point they are being produced before they escape into the workroom air. The system consists of hoods, ductwork, a fan, and possibly an air-cleaning device. It works by removing the contaminant, not just diluting it, making it more economical over the long term. However, the system must be properly designed with the correctly-shaped hoods and correctly-sized fans and ductwork.

Lower Explosive Also known as the Lower Flammable Limit (LFL). The Limit (LEL) lowest concentration of a substance that will produce a fire or flash when an ignition source is present. It is expressed in the 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)

Lung Hazards Signs and symptoms

Melting Point The temperature at which a solid changes to a liquid. A melting range may be given for mixtures.

MPPCF "Millions of particles of particulate per cubic foot of air."

Material Safety Data Safety information about a chemical provided by the

Sheet (MSDS) manufacturer or distributor. OSHA regulations require that an MSDS for each chemical in use in a laboratory be accessible to every employee of that laboratory.

Mutagen Anything that can cause a change (or mutation) in the genetic material of a living cell.

Narcosis Stupor or unconsciousness caused by exposure to a chemical.

Nephrotoxins Chemicals which produce kidney damage. Signs and symptoms: edma, proteinuria; chemicals: halogenated hydrocarbons, uranium.

Odor Threshold The minimum concentration of a substance at which a majority of test subjects can detect and identify the substance's characteristic odor.

Oxidation The process of combining oxygen with some other substances or a chemical change in which an atom loses electrons.

Oxidizer A substance that initiates or promotes combustion in other materials, thereby causing fire either of itself or through the release of oxygen or other gases.

Oxygen Deficiency An atmosphere having less than the normal percentage of oxygen (20%) found in normal air.

Permissible Exposure The term used by OSHA to indicate the maximum air Limit (PEL) concentration to which employees can be exposed. PEL may either be a time-weighted average (TWA) exposure limit (8 hour), a 15 minute short-term exposure limit (STEL), or a ceiling (C).

Personal Protective Any devices or clothing worn by the worker to protect Equipment (PPE) against hazards in the environment. Examples include respirators, gloves, lab coats, and splash goggles.

PPM Parts (of vapor or gas) per million (parts of air) by volume.

Polymerization A chemical reaction 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.

Pyrophoric A chemical that will ignite spontaneously in air at a temperature of 130o F or below.

Reactivity A substance's susceptibility to undergoing a chemical reaction or change that may result in dangerous side effects, such as explosions, burning, and corrosive or toxic emissions. The conditions that cause the reaction, such as heat, other chemicals, or dropping, will usually be specified as "Conditions to Avoid" when a chemical's reactivity is discussed on a MSDS.

Reproductive Toxins Chemicals which affect the reproductive capabilities, including chromosomal damage (mutations) and effects on fetuses (teratogenesis). Signs and symptoms: birth defects, sterility; chemicals: lead, DBCP

Respirator A device which is designed to protect the wearer from inhaling harmful contaminants.

Respirator 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 impairment of a bodily function.

Risk Assessment Evaluation of existing hazards concerned with a procedure or process in the work environment.

"Select Carcinogen" See Appendix C for the full definition.

Short-term Represented as STEL or TLV-STEL. The maximum exposure limit concentration to which an employee can be exposed for no more than 15 minutes at a time no more than 4 times a day. There must be at least 60 minutes between exposures at the STEL level. Also, the TLV-TWA must not be exceeded.

"SKIN" This designation sometimes appears on an MSDS 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 so that the TLV is not invalidated.

Skin Hazards Chemicals which affect the dermal layer of the body. Signs and symptoms: depletion of fats of the skin, rashes, irritation; chemicals: ketones, chlorinated compounds.

Systemic Spread throughout the body, affecting many or all body systems or organs not located in one spot or area.

Teratogen An agent or substance that may cause physical defects in the developing embryo or fetus.

Threshold Limit Airborne concentrations of substances devised by the Value ACGIH that represent conditions under which it is believed that nearly all employees may be repeatedly exposed, day after day, without adverse effects. TLVs are advisory guidelines, not legal standards, that are based on evidence from industrial experience, animal studies, or human studies when they exist. TLVs include: Time Weighted Average (TLV-TWA), Short- term exposure limit (TLV-STEL), and ceiling (TLV-C). (see also PEL)

Time Weighted Represented as TLV-TWA. The average time over a Average given work period (e.g., a normal 8-hour work day) of a person's exposure to a chemical or agent. The average is determined by sampling for the contaminant throughout the time period.

Upper Explosive Also known as the Upper Flammable Limit (UFL). Limit (UEL) The highest concentration of a substance that will burn or explode when an ignition source is present. It is expressed in the percent of vapor or gas in the air by volume. Above the UEL or UFL, the air/contaminant mixture is theoretically too "rich" to support combustion. The difference between the LEL and the UEL constitutes the flammable range or explosive range of a substance. That is, if the LEL is 1 ppm and the UEL is 5 ppm, then the explosive range of the chemical is 1 ppm to 5 ppm. (see also LEL)

Unstable A chemical which in the pure state, or as produced or transported, will vigorously polymerize, decompose, condense, or will become self-reactive under conditions of shocks, pressure, or temperature.

Vapor The gaseous form of substances which are normally in the liquid or solid state (at normal room temperature and pressure). Vapors evaporate into the air from liquids, such as solvents. Solvents with low boiling points will evaporate readily.

Water-Reactive A chemical that reacts with water to release a gas that is either flammable or presents a health hazard.

ACGIH The American Conference of Governmental Industrial Hygienists is a voluntary membership organization of professional industrial hygiene personnel in governmental or educational institutions. The ACGIH develops and publishes recommended occupational exposure limits each year called Threshold Limit Values (TLVs) for hundreds of chemical, physical agents, and biological exposure indices.

ANSI The American National Standards Institute is a voluntary membership organization (operating with private funding) that develops consensus standards nationally for a wide variety of devices and procedures.

DOT The Department of Transportation is the Federal Agency that regulates the labeling and transportation of hazardous material.

EPA The Environmental Protection Agency is the Federal Agency responsible for administration of laws to control and/or reduce pollution of water, air, and land systems.

IARC International Agency for Research on Cancer.

NFPA The National Fire Prevention Association is a voluntary membership organization whose aims are to promote and improve fire protection and prevention. The NFPA has published 16 volumes of codes known as the National Fire Codes. Within these codes in Standard No. 704, "Identification of the Fire Hazards of Materials." This system rates the hazards of a material during a fire. These hazards are divided into health, flammability, and reactivity hazards and appear in a color-coded diamond system using from 0 ( no special hazard) through 4 (severe hazard) indicated severity of the hazard.

NIOSH The National Institute for Occupational Safety and Health is a national organization that, among its various responsibilities, trains occupational health and safety professionals, conducts research on health and safety concerns, and tests and certifies respirators for use in the workplace.

NIHS National Institute of Health Science.

NSF National Science Foundation.

OSHA The Occupational Safety and Health Administration is a federal agency under the Department of Labor that publishes and enforces safety and health regulations for most businesses and industries in the United States.