Chemical Education Today
Letters
Chemical Inventory and MSDS Systems The article by James Hunsley in the June 1995 issue does an excellent job of reviewing PC-Based Chemical Inventory and MSDS systems. The author states that “Both up-to-date inventories of, and MSDS’s for, hazardous chemicals for each area where the substances are used…are required components of the laboratory Chemical Hygiene Plan (CHP) as promoted in OSHA Laboratory Standard.” Although having both is an excellent idea and widely regarded as good practice, in fact, 29CFR1910.1450 requires neither. The only statement in the law related to MSDSs is one to the effect that if they are received, they must be retained and made readily available to employees. Furthermore, the law makes no reference to chemical inventories. The appendices of the lab standard are intended only as recommendations. They create no legal obligations. Many readers of this regulation mistakenly believe that the model CHP in appendix A represents a requirement. It is not. It is only a recommendation. Similarly, while reading our Laboratory Safety Guidelines (which is referenced in appendix B of the standard) is a good idea, unfortunately, doing so is only a recommendation! Fortunately, more than 2 million copies have been distributed so far. If you would like a free copy, fax your request to me at 1-508-647-0062. James A. Kaufman Director, The Laboratory Safety Workshop A National Center for Health, Safety and Environmental Affairs 192 Worcester Road Natick, MA 01760
James Hunsley replies: The letter by James A. Kaufman about my article, PC-Based Chemical Inventory and MSDSs in the Chemical Hygiene Plan, in the June 1995 issue, centers around the use of the word “required” in discussing use of MSDS sheets and chemical inventories in the chemical hygiene plan. He is in error when he says there is “only” one statement in the law related to MSDSs, referring, I assume, to part (g), (4), (D), (ii), “Employers shall maintain any material safety data sheets that are received with incoming shipments of hazardous chemicals, and ensure that they are readily accessible to laboratory employees.” For instance, under part (f) Employee information and training. (3) Information. it states that “Employees shall be informed of: (v) “The location and availability of known reference material on… hazardous
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chemicals found in the laboratory including, but not limited to, Material Safety Data Sheets received from the chemical supplier” (my underlining). A reasonable interpretation of this statement, which many academic and industrial laboratories have taken, is that MSDSs are, in fact, required and not just limited to those automatically received. With regard to chemical inventories, Kaufman has a point and my use of the word “required” here should have been to my reference 2 (1). In this ACS pamphlet, the authors state categorically that, in developing a chemical hygiene plan, “The development of an inventory is mandatory.” The statement that an inventory is necessary stems, not from a mistaken belief that the appendices of the lab standard constitute a requirement, but from the concern that hazardous chemicals will be overlooked. It is difficult to see how the requirements of the law can be met without an inventory. Again, both academic and industrial laboratories have made this working assumption. Literature Cited 1. Young, J. A.; Kingsley, W. K.; Wahl, G. H., Jr. Developing a Chemical Hygiene Plan; American Chemical Society: Washington, DC, 1990.
James R. Hunsley Southern Illinois University at Edwardsville Edwardsville, IL 62026-1652
Egg in the Bottle According to the note entitled “Getting the Egg Out of the Bottle” by Doris Kolb, Susan Grzanich, and Peggy Carrigan (J. Chem. Educ., June 1995, page 527), “the burning paper uses up the oxygen inside the bottle, thus reducing the pressure.” The loss of oxygen is only part of the overall picture. The number of moles of oxygen consumed during most combustion reactions usually equals the number of moles of carbon dioxide and/or water vapor produced. As a result, either no change or only a slight change in pressure occurs. Two other effects make a greater contribution toward reducing the internal pressure: (1) the cooling of the gas inside the bottle after the flame is extinguished, and (2) the condensation of water vapor. The first reduces the pressure by reducing the speed of the gas molecules inside the bottle, and the second reduces the pressure by reducing the number of gas molecules inside the bottle. Ronald DeLorenzo Middle Georgia College 1100 Second Street, S.E. Cochran, GA 31014-1599
Journal of Chemical Education • Vol. 73 No. 9 September 1996
Chemical Education Today
Letters
The note “Getting the Egg Out of the Bottle” (Kolb, Grzanich, and Carrigan, June 1995, p 527) teaches a nifty trick that will be helpful to demonstrators. But the explanation of how the egg got into the bottle is off the mark. The reason is not that the oxygen is used up (by the burning of the paper) “thus reducing the pressure”. The oxygen gas is replaced by an equal amount of carbon dioxide. The cause of the pressure drop within the bottle is surely the cooling of the high-temperature gases of the flame when the flame is extinguished. Michael Moran West Chester University West Chester, PA 19383
Doris Kolb replies: I deeply regret the error that appeared in the June 1995 issue of the Journal (page 527). The drop in pressure that allows the egg to be pushed into the bottle is due, of course, to the drop in temperature when the oxygen has been used up and the flame goes out. There is a related demonstration in which a small candle implanted in a cork is floated on a dish of water. An inverted drinking glass is lowered over the burning candle until the rim is below the surface of the water. The candle flame soon goes out as the oxygen inside the glass gets used up. Meanwhile, the water level inside the glass rises because of the reduced gas pressure in the glass. In this case the reduced pressure is due primarily to the disappearance of oxygen, since the gas is in contact with water and carbon dioxide is water- soluble. (When the dish is filled with limewater, it turns milky.) I suspect that I had that demonstration in the back of my mind when I mistakenly attributed the pressure drop in the egg experiment to the disappearance of oxygen. In any case, that note was not about getting the egg into the bottle but getting it out. During a workshop for teachers I had been trying unsuccessfully to remove a very stubborn egg from an unyielding bottle. The egg kept getting stuck in the neck of the bottle. When two middle school teachers (Susan Grzanich and Peggy Carrigan) asked if baking soda and vinegar might work, we added a spoonful of baking soda and a little vinegar to the bottle, gave it a quick swirl, and turned the bottle upside down. The egg popped right out into my hand. It is a simple technique that seems to work every time. What a pity that their useful idea had to be marred by my faulty and much too hasty write-up! Doris Kolb Bradley University Peoria, IL 61625
Helping Dyslexic Students I found the letter from F. L. Himes in the September, 1995, issue about dyslexic students to be most interesting, especially the part about the tape recorder. Many people are not aware that there is an organization called “Recording for the Blind and Dyslexic” (former name: “Recording for the Blind”) that records textbooks in all subjects and lends them free of charge to blind and dyslexic people, mostly students. If readers know of such students, the organization can be reached at its national headquarters: 20 Roszel Road, Princeton, NJ 08540; (1-800-221-4792). Volunteers for reading are always welcome. There are more than two dozen studios located in large and small cities all over the country, including for example, New York, Chicago, Washington, Louisville, and Santa Barbara. Readers who can handle chemistry books are especially welcome, since few nonchemists can do that. Though the volunteers are unpaid, they receive much personal satisfaction in providing this much-needed service to thousands of students (I have been doing it for nearly ten years). Potential volunteers can get further information, including the location of the nearest studio, at the above address. Jerry March Adelphi University Garden City, NY 11530
About Letters to the Editor Letters to the Editor may be submitted to the editorial office by regular mail (JCE, University of Wisconsin–Madison, Department of Chemistry, 209 North Brooks, Madison, WI 53715-1116), by FAX (608-2627145), or by Email (jce@chem. wisc.edu.). Be sure to include your complete address, your daytime phone number, and your signature. Your letter should be brief (400 words or less) and to the point; it may be edited for style, consistency, clarity, or for space considerations.
From Neil Gordon, Editor 1924–1932 “Every successful teacher must have an interest in research in chemical education. Whether he can carry on experimental or theoretical investigations that will fill the pages of our journals is not now the question.” 1, 65 (1924)
Vol. 73 No. 9 September 1996 • Journal of Chemical Education
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