d e t y in the chernkol loborotory
edited by MALCOLM M. RENFREW University of Idaho MOSCOW.Idaho 83843
The Role of Labeling in Chemical Health and Safety: Recent Developments Jay A. Young, Consultant 1 2 9 1 6 Allerton Lane, Silver Spring, MD 2 0 9 0 4
use it, and have it handy, fully charged and applied depend upon the properties of each chemical. In every instance the properties must be learned-they are not intuitively known-and the appropriate precautions must be deduced and then applied. Given the variety of chemicals each with unique praperties and the variety of possible precautions,
day a. roung is a cnemcal consultant Specializing in the safe manufacture, use, precautionarq labeling, proper handling, and appropriate disposal of chemicals used in industry, the household, and the laboratory. He writes articles and books, and o r g a s and participates as a contributor to conferences. seminars, and symposia in these areas. He deposes andlor testifies as an expert witness (for plaintiff or defense) in litigations involving chemicals or chemical reactions and product liability. He is Editor Of the International Journal of Chemical Health and Safety
can he stated in a few words such as these: Interpose physical barriers (or distance). Use small quantities of a chemical either directly or through dilution. For incompatible chemicals, avoid both inadvertent mixing and storage in adjacent locations. Know which kind of fire extinguisher is suitable, how to
Most recently (1977-80)Dr. Young was the Manager of Technical Publications for the Chemical Manufacturers Association. Dr. Young taught far many years et King's College in Pennsylvania and was a Visiting Professor at Carieton University in Onawa. He taught for seven years in Southeastern United States and was associated with the lSiS project at Florida State University. Dr. Youna is the author of several articles on tne leachmg of cnem ss,, most of them p.0- snaa n 'he .o.ahn. uk C-rucn t ~ . .CAT Oh Tnese ano alher P L 1' ~81 o m nciuding more than a dozen books, have stressed laboratory as a means of instruction and the importance of strategies designed l o enhance individualstudent contacts with their professor in both large and small class environments. Cbrrenlly nc s muui.ed n ~ nal h onn y oused Groups He senm for man, )ears as Secrelary of the ACS D,, ston of Cnemcai Education and member of the Board of Publicationof the Journal of Chemical Education and also has been a member of various ACS Council committees, chairman of various comminees and subcomminees, or a member of such, in the ACS Oivisians of Chemical Health and Safety and of Education, of NSTA, and other organizations. including the National Advisory Council on College Chemistry. He is a fellow of the AAAS and a founding (charter) member of the American Conference on Chemical Labeling.
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How small quantity or what degree of dilution? Is a hood really necessary (and is it in operating condition)? Will these two unfamiliar chemicals react violently? Selection of the suh-set of proper precautions from the set of possibilities is hidden in a variety of decisions. First the hazardous properties must be learned: then oarticular orecautions can he selected. 1f we'consider concentrated hydrochloric acid, or, say, acetone, mast chemists know the hazards and can select the precautions to be taken. But what ahout beginning chemists, or the janitors or maintenance personnel? What about the hazardous properties of hexane, or zirconium carbonate, or pyrilamine maleate? Which if any afthese is toxic, or flammable, or reactive? And how toxic, to what degree flammable, how reactive and with what? Selection of the suitable precautions requires either an encyclopedic knowledge of the properties of all chemicals or access to references that contain the information. Failing this, one can of course guess and hope. Often, flammabil~tyand corrosivity can he rather reliably estimated from general chemical knowledge; toxicity cannot. Even reactivity with other chemicals is full af surprises. The history af chemical use is replete with anecdotes, a few humorous, too many tragic. I t is the function of the lshel to inform users of chemicals of the hazards and of the those hazards.
andtoselect and then describe the reasonable precautions that should he taken to prevent otherwise foreseeable harm. Precautionary (Continued on page A142)
Volume 6 0
Number 5
May 1 9 8 3
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labeling for chemicals is less than 100 years old. This art has progressed sporadically until about 1945 and in an organized manner since then to its present state.' Recent developments in efficient communicatian through the use of combined numeric and pictorial symbols are described here. Any given chemical can be hazardous in one or more of fourZdifferent ways, as a: Health hazard Flammability hazard Reactiuity hazard
Contact hazard
the danger or toxic effect a substance presents if inhaled, ingested or absorbed. the tendency of a substance to burn. the potential of a substance to explode or to react violently with air, water, or other substances. the danger a substance presents when exposed to skin, eyes, or mucous membranes.
Each of these four kinds of hazard can vary in their degree of potential harm. Somewhat arbitrarily, five degrees of hazard are recognized and identified by numbers: 0 No significant hazard 1 Slightly hazardous 2 Moderately hazardous 3 Severely hazardous 4 Extremely hazardous. The numbers appear on a label in order, from left to right, denoting the degrees of hazard for health, flammability, reactivity, and contact.
so-called life symbol and the word, "cancer". The hazard symbols used when a degree of hazard is rated at "3" or "4" (severe or extreme hazard) are shown in Figure 2. When a health, flammability, reactivity, or contact hazard is unknown, aquestian mark symbol is used; any chemical so labeled should be considered to be extremely hazardous and handled accordingly until proved otherwise by facts known to the user. In addition to descriptions of hazards, a label should prescribe the precautionary steps to be taken to minimize otherwise fore seeable harm arising from the hazardous ~rooertiesof a chemical. Pictorial svmbols &e "sefuk the" are shown in Fieure 3 (also see the precautionary steps include wearing protective gear, using a hood, and access to the proper type of fire extinguisher (type- A, B, or Note that the symbols in Figure 3 identify protective equipment for the labaratory, not necessarily for the industrial workplace where the hazards sometimes differ in degree andlor kind. The "Stop Sign" symbol in Figure 3 is used when the appropriate precautionary steps cannot be described by one or more of the other symbols 'See, for example, the seven successive editions of "Guide to Precautionary Labeling of Hazardous Chemicals, Manual L-I," Labels and Precautionary Information Cammittee, Manufacturing Chemists Association (now Chemical Manufacturers Association), Washington, DC, 1945, 1946, 1949, 1953, 1956, 1961,and 1970. Also see the so-called eighth edition of this ~uhlication."American ~ i t i o n a lStandard ror the ~recantionarv
in press. As defined by the J. T. Baker Chemical Company, Phillipsburg, NJ, private communications. for the J. T. Baker "Saf-TData'"" labeling system. The Fisher Scientific Company has just announced a related but different "ChemAlertTM" system based an similar but not identical definitions. It can be anticipated that other suppliers will introduce their own labeling systems, each with different but related definitions. Unless users are thoroughly familiar with the eccentricities of each of their suppliers labeling systems, the consequent confusion could lead to less, not improved, safe use, handling and storage of chemicals. Steps toward uniformity are being taken but the process may require several months. This mnemonic for fire extinguisher type may he useful: ~~~~
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Figure 1 illustrates the numeric symbols for the hazards of 50% (wtlwt) aqueous sodium hydroxide solution in the ton horizontal row. ~ h u sand . in order left to &ht. this cocorrosive to skin, eyes and mucous membranes. Whenever the degree of hazard is numerically rated at "3" or "4",a pictorial symbol is shown along with thenumber; thus, note the health and contact hazard symbols in Figure 1. A substance known to cause cancer in humans, for example, would be rated with a "4" in the health category; the upper left block would then show a "4" accompanied by the A142
Journal of Chemical Education
upon combustion. B suggests Boiling andBubbling; use a type B extinguisher on fires of burning liquids (they boil and bubble as they burn). D suggests Doggone gaod, hot, fires; use a type D extinguisher on fires of burning metals (they burn doggone gaod in a hot fire). (Type C extinguishers are used an fires involving Charged electrical circuits. Type E fire extinguishers are used on fires in^ volving everything Else.)
of Figure 3. A Stop Sign also carries the wording, "Exceptional hazard; read the material safety data sheet." This indicates that the labeled substance can be extremely hazardous and that it should not be used or handled until the appropriate precautionary steps are known and understood as described in the material safety data sheet for the chemical involved. Wide ranging and reliable statistical surveys have not been made, hut causal studies suggest that improper chemical storage is responsible for more adverse incidents involving chemicals than any other single cause. Hence, good chemical health and safety practices include storage based on chemical principles. Chemicals that react with each other violently, for example, should not be stored near each other. Solid colors and striped colors are used as a code. The solid or striped color appears around and in between the numeric and pictorial symbols. The colors and stripes and their meanings are
signifying flammability hazard; store in a flammable chemicals srumgr area. Es3rnplv. 3
