mfety in the chemkal laboratory
edited by MALCOLM M. RENFREW University of Idaho MOSCOW, Idaho 83843
Flood Control Bruce D. Pollard Marquette University, Milwaukee, WI 53233
Perhaps the most frequent chemical spill in the laboratory is the common flood. Certainly, all but the most theoretical of chemists have either caused or been a victim of large amounts of water spewing from condenser hoses, dripping from the ceiling, or emanating from overflowing drains. Only the most ideally built laboratories, where all rooms are on one floor and all of the floor within one room slants a t a 10' angle to a drain, are floodproofed and thereby minimize the unhealthy interaction between co-workers when one floods out another. A recent flood in the Marquette University Todd Wehr Chemistry Buildine has nrecioitated this contribution.
structure, floors five and six containing the research labortories and the lower floors containing student laboratories, lecture halls, and other offices. The organic and inorganic synthetic chemists are located on the 6th floor convenientlv close to the hood svstems
one day in June, a graduate student prepared to do a 24-h Soxhletm extraction as required in a literature oreoaration. He assembled the apparatus on-his workbench, attached the quick-connect hoses, adjusted the heating rate using his Variac" until the Soxhlet was operating properly, checked it periodically during the day, and left for the evening. At 5:30 a.m. the next day, another ambitious graduate student arriving a t the laboratory discovered a waterfall cascading down the
Bruce D. Pollard is Assistant Professor of Analvticai Chemistrv and Denartmental Safetv Caordinator at Marq~ene.nt\ers I) he nolds a OSaegree n cllem arb IromCnrroll Co ege in W scons nand a PhD n ann ,I cnl cnmor'!) from tne Jn versftv of Florida. He has worked in the environments engineering laboratory at Dow Chemical. Research interest$ include developing new instrumentation for process control and environmental or work place monitorina. He teaches instrumental analvsis. specoascop c lnsVJment desogn. m a i n w l prouem ralrmg. ana comprran8cs for sc entorts he s an ACS member and a past president of the Milwaukee Section of the Society for Applied Spectroscopy.
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back stairway between the 5th and 4th floors of the building. Being conscientious he called the Public Safety Office of the University, which dispatched an officer to investigate, and then called his advisor (the author and departmental safety coordinator by default) who headed to work early. While waiting for the arrival of the Public Safety Officer, our hero wandered around the building until it was clear that the water was at least partially emanating from beneath the 6th floor door of one of his ca-workers who had been doing a Soxhlet extraction. Upon the arrival of the Public Safety Officer who had the necessary keys they together entered thelaboratoryand found the source hose to the Soxhlet condenser spilling water out onto the floor. Because there were a number of electrical cables in the same laboratory, the graduate student found two chairs, used them as stilts, waded into the laboratory, and turned off the water. He then evaluated the possible electrical hazards and turned off appropriate switches and circuit breakers. Then he surveyed the extent of the flood. He found water 2 cm deep in the NMR laboratory next door, but the instruments wereon blacksand not damaged. On the 5th floor he found waterjust starting to drip onto the laser Raman instrumentation and quickly covered it with plastic bags. On the 4th floor he found water coming out of the quantitative analysis stockroom, entered it, and moved to a place of safety several reagents which were directly under dripping water. He also found water in the 3rd and 2nd floor stockrooms. Then the advisor arrived, and they began to clean up the water starting a t the source. Wet vacs (an industrial type vacuum cleaner which will safely suck up water) and sponges were used. Safety glasses, rubber gloves, and insulating shoes were worn. Other students, faculty, and maintenance personnel were called, and the clean-up continued intensely for 3 hr. Six hours later ceilings were still dripping owasionally, but things were reasonably dried out. Based on the number of times the wet vacs were emptied, the flood volume was estimated a t 600 1. Luckily no major damage was caused and a valuable lesson was learned. In nature, floods are acts of God, but in the chemical laboratory, floods are preventable accidents that still happen. Although the substance involved is primarily water, floods are in fact chemical spills with specific hazards and should be treated as such. Seven Volume 60
Seven Steps of Flood Control 1. 2. 3. 4. 5.
Prevention Minimization Early Detection Stopping the F l w d Evaluation 6. Clean-Up 7. Documentation
steps of flood control are listed in the Table. The remainder of this contribution comments on each individual step. These steps t G a r d s flood control must be included in the safetv education of everv laboratorv worker. personnel. As in all safety matters, prevention is the foundation of a good program. Education is extremely important; workers who know what to do have same chance of doing it. Water is required for cooling and other laboratory functions and, therefore, cannot he eliminated from possible spillage. To minimize the possihilty of a flood, water usage should heconsidered in a fashion and with a degree of severity similar to that of electrical circuits. All connections should be secured, using, as listed in the order of preference: permanent fittings, screw-type hose clamps, finger-type hose clamps, or strong wire. When wire must be used;make two loops before twisting to tighten; one loop is ineffective and more than two is less secure. Tubings and other components in the water circuit should be free from cracks, tension, and isolated from possible sources of physical damage such as heaters or sharp edges. Both the source and drain should be secured and leak free. The source flow rate should be adjusted with the most restrictive component in the water circuit in mind so that pressure will not build up and burst a hose. After the water circuit is constructed, it should be critically inspected by the builder and a devil's advocate co-worker. Periodic inspection of water circuits under continuous use should be
(Continued on page A336) Number 12
December 1983
A335
While sand bags are not necessary, steps to minimize the damage caused hy any size ilond are dictated. Knowledge of the flood history of your building is invaluable. Every building has its characteristic paths where water flows under cabinets, through cracks in walls, and dawn through cracks and holes where plumbing and electrical fixtures pass from one floor tv another. The simplest steps, using this knowledge, are to designate the f l o d p n m e areas of a building as temporary usage areas where instruments cannot be located or water-sensitive articles stored. A more cvstly approach is to seal the cracks and holes, particularly those between floors, with caulking or some other suitable material. Remember, however, that water must go somewhere. If no drains are available on the
If equipment or condenser hoses are left running overnight, key-point cards telling how to turn the equipment off safely in an emergency should be posted in an ohvious and accessible area. Emergency cards listing persons to call and their phone numbers should be pvstedon the door of every working laburatmy. Departments doing a consider-
A336
Journal of Chemical Education
able amount of overnight work should consider purchasing additional safety equipment. Flow monitors which set off an alarm vr turn off the water and electricity when the drain tlow ceases are available (Instruments for Research and Industry, Cheltenham, PA, sells a complete line). Another possibility would be to substitute a closed-cycle water circulator fvr an open-cycle water tap. This would restrict the total flood quantity to only the volume of the circulatory system. Goad monitarine.. nractices will facilitate . eddy detwism of,, t.wd. \Vhi.e e ~ m t ~ n u u u < is ntll practical. ~ n ~ m i 111 l ~dllmfluw ~ ~.\.%tern$ ~ r ~ p t d t dclwchs, ~ m >ut n l y d the I l ~ ~ ~ v but the entire apparatus, are a good idea. Each worker should check his or her work area befvre leaving a t night and, if an experiment is left on overnight, provisions for periodic checking should be made, if possible. Securitv ~ e n o n n eshould l oatnd the hallwavs left open for inspection. When a possible flood source or leak is detected it should he slopped safely as soon as possible. Execution of this task requires trained personnel, key-point cards, and pwper labeling of water and electrical outlets. Water spigots should be located in a place where they can be readily reached without the danger of electrocution. Those qualified to stop floods should he made aware that turning off any part of a system necessitates that it be turned off entirely. Special provisions should be made for floods caused bv leaky nines and drains in the ceilines and walls. whom to call and possible shut>fflocations should be posted.
Swift but total evaluation vf the ihwd situation should he made using sound principles of chemical safety. Because the water ilvw could be contaminated with chemicals from a broken apparatus, reagent bottles, or chemical residues on an unclean floor, the flood must be treated a t least initially as a chemical spill. In addition, the flood will conduct electricity, so all electrical circuitry and outlets exposed to flood water must be identified and safely turned off. This can facilitated by using key-point cards and having a laboraton-wide electrical diaeram. Quick t e ~ ~ ~ sensitive apparatus. The apparatus and personnel required to clean up a flood depend upon its scale. If suitable equipment is available and ready and people are p&erly trained in its use, flood clean-up can he expedited and damage further minimized. The availahilitv of a vacuum . ~ + m e rrho1 ..wks up w t m I$ e w n t t ~ l:\low w ~ the h urt wr. maq,.. I,uckrt\,adr2nn wtn water rinse, sponges, and wipes should all be lncated in an easy-to-reach unlocked storage area. In addition, because the h o d may be chemically dangerous, safety goggles, glasses, gloves, and rubber hoots should he worn by clean-up personnel. Clean-up should proceed in a fashion to minimize damage. Usually this is best done by starting a t the source and, in the case of multi-floored buildings, from the top dawn. Rapid work as a team is ideal. Because water may be missed the first time or seep out from cracks and crevices, a second pass later in the day may be required. Good ventilitatiun to soeed drvine . .. is necessarv to prwrnt I I I I I ~ ~I t, ~i?nllrU, r e - e ~ n ~ h . v i ~ m g that dl p e r i w w l i~~\ldvr.d i n tht i.lei
