Quick, Inexpensive, and Convenient Protection for Mercury-Filled McLeod Gauges The environmental health hazard of mercnry has mast recently been brought to the attention of all who work in the chemical industry. The toxicity associated with small spills of mercury in the chemical laboratory can often produce vapor concentration in excess of the threshold 1imit.l This toxicity, combined with the improbability of total clean-up, forces all who use mercury to seek containment as a means of stopping .. .mercury contamination in the event of accidental spills. A recent articlea describes a "Safety Enclosure far Mercury-Filled McLeod Gauges!' While this device seems adequate to contain mercury in case of McLeod gauge breakage, its bulkiness and having to open a door makes it cumbersome to use in afume hood. In our laboratory, as a solution to containing mercury in case of McLeod gauge breakage, the glass portion of the The bags are secured a t the back with a wire or rubber gauge is enclosed in one or two lsrge Ziplo@ plastic band. Enclosing the McLeod gauge in low-cost polyethylene bags provide a quick, inexpensive, and convenient solution to the problem. Most important, however, is the fact that even with two protective bags over the McLeod gauge the operation of the instrument is not impaired, and the bags have adequate transpsrency to permit clear observation of the millimeter scale for vacuum meamrements. 'SAX, N. I., "Dangerous Properties of Industrial Materials" (2nd Ed.), Reinhold Publishing Corporation, New York, 1963, q. 971. FASSETT,D. W., AND IRISH,D. D. (Editom), "Industrial Hydiene and Toxicology," Interscience Publishers (dwision of John Wiley & Sons, Inc.) New York, 1963, Vol. 11,p. 1104. 47,755 (1970). LIPPERT,E. L., JR.,AND GLAS,J. P., J. CHEM.EDUC., Ziploc is Dow's registered trademark for plastic food storage bags. Large size is 10Q/lsX 11 in. LARRYR. COLLINS
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