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in the Chemical laboratory Edited by NORMAN V. STEERE, 140 Melbourne Ave., S.E. Minneapolis, Minn. 554 14
LIX. Safety Manuals and Handbooks c.
Safety Handbook, Chemistry Dept., Ohio Stote University
E.W. BOWERMAN, P.M. HARRIS,A. J. KRUBSACK, E. P. SCHRAM and T. R. SWEET, The Ohio State University, Columbus, Ohio 43210 Authors' Note An effective safety program in a chemistry department requires total commitment hy its faculty to the program. The key to this commitment is the development of a. reasonable set of guidelines on safe practices under which the faculty is willing to operate and assume responsibility, such that safety consciousness plays an integral role in the planning and execution of all laboratory operations. This handbook is t,he result of action hy the faculty of the chemistry department a t The Ohio State University to develop such a set of guidelines. I t will be noted that the responsibility for the program rests with each individual member of the department through regular organizational lines. The materials compiled by the committee responsible for the p r e p eration of the handbook came from many sourws, and no effort has been made to document them. The handbook is being offered for publication in bhis format with the hope that i t will stimulnte both college and high school teachers to promote safe practices in their chemical laboratories.
SAFETY HANDBOOK Table of Contents Tothestuden1 . . . . . . . . . Laboratory Safety Roles . . . . . Safe Pracbices . . . . . . . . . . SP-1 General Work Practices . . SP-2 Housekeeping . . . . . . SP-3 Handling Chemicals . . . RP-4 Chemical Waste Disposal . SP-5 Handling Compressed gas Cylinders . . . . . . . . SP-6 Handling Equipment and Appamtus . . . . . . . . SP-7 Handling Laboratory Glassware . . . SP-8 FirePrevention . . . . . Accident Report Format . . . . . Chemistry Department Safety Organization . . . . . . . 1. ResponsihiMy for Safet,y . . . 2. Central Safety Committee . . 3. Department Safety Coordinator . . . . . . . . 4. Group Safety llepresentstive . 5. Teaching Assistant Duties and Ilesponsihilities for Safety . .
To the Student: Experience has demonstrated the necessity of maintaining a constant awareness of tho hazards attendant to experimental
work performed in bhe study of chemistry. Experience also shows that the best way for a student to protect himself and his coworkers is to incorporate safety a? an integral part of each task and operation. Those studying chemistry, bath a t the undersraduate and graduate level, are expected to exhibit good judgment hased upon t,heir chemical knowledge and upon common sense in preventing haaardous situations. The student is expected to make a, careful analysis of each operation for safety. In doing this, he collects information pertinent to the job from the literature and his msociates. On the basis of this information he forecasts potential hazards and decides how to circumvent the hnaards through the application of safe techniques and the use of proteotive eqt~ipment. Finally, he plans a precautionmy course of action in t,he event an accident occors because of unforeseen factors. An analysis of many accidents over the years indicates qnibe clearly that poor housekeeping in tho laboratory, poor understanding of the properties of the chemicals used, improper use of tools and equipment, improper selection of clothing, and poor judgment on the part of the student are important contributory factors to laboratory accidents. To assist you to plan and conduct your experimental work safely, a set of safety rules and a. number of safe practices have been compiled in the handbook for your use. I t must he remembered that these safe practices are not hard and fast mles and that all circnmstances are not covered. If under exceptional circumstances good judgment indicates certain of these practices should not he followed, then you should make certain yoit are not creating a hazard by selecting a different procedure.
LABORATORY SAFETY RULES I . Eye Protectia: All students must wear safety goggles or indostrial quality safety spectacles in laboratories where chemical work is done. 2. Warning Signs: "No smoking," "Caution-Radiation Ares" or other warning signs must he strictly obeyed.
feature
To help those who may have responsibility for developing written safety guidelines for a laboratory, we continue a series of excerpts from some laboratory safety manuals and handbooks. The series will include examples of detailed safety practice, basic safety policies, reasonable safetv reeulations. and flexible administrative &oecdures. Table of eontents is listed only to show extent of coverage and variations between organimtions. Specific questions or comments about any manual or handbook excerpt should he directed t o the contact person noted at the end of the article. Whether or not they can provide copies of their manual will depend on the policy of their organization. I n a later issue, we plan to have a. report of progress on the development of a comprehensive laboratory safety manual by the Researoh and Development Seotion of. the National Safety Counoil. one of three groups active in laboratory safety. The American Chemiesl Sooietr and the National Fire Protection ~ss&iationboth have committees working on guidelines and standards that will be appropriate in a laboratory safety manual. Purposes and activities of the three groups will be described here in the near future.
. Horseplay and practical joking of any kind is strictly forbidden. 4. Labeling Containers: All containers of chemicals must be clearly labeled showing the name of the chemical, date, owner's name, and safety precautions if hazardous. 6 . Searing Compressed Gas Cy1inde1.s: Compressed gas cylinders must be secured with a strap or chain a t d l times. 6. Working Alone: No one is to perform experimental work in a chemicd laboratory unless a second person is present or located within calling distance.
7. Work Authorizaiiont Unauthorized experiments are forbidden. Before any experiment is performed in an instructional laboratory, approval must he given by the instructor in charge. Experimental work in r e search laboratories must be a part of the program approved by the research p r e ceptor. 8. Radiatia Hazards: Experimental work with radioactive materials or equipment generating ionizing radiation is strictly forbidden without official approval from the University Radiation Committee. Approval for such work may be requested by the Preceptor who will contact the Supervisor of University ltadiation Safety.
(Continued on pago 11598)
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9. Reporting Aeeidenls and Fires:
All accidents resulting in injury, property damage, or fire must be reported promptly to the appropriate supervisor and to the Central Safety Committee Chairman. (See section on General Safe Practiea, SP-1, for instruction on report,ing.)
SP-1 General Work Practices A . Laboratow Layout and Facilities It is important that graduate students, postdoctoral fellows and faculty assigned to a given laboratory make a thorough safety assessment of the facility before starting work. The scope of such a safety check of the laboratory layout should include: L o d i n g the exits from the laboratory arid from the building. Are the aisles, stairwells, and corridors clear? State codes forbid blocking of all passages to exils. Locating the fire doors. State codes require that fire doors be kept closed. Locating the nearest telephone for use in case of a n emergency. Locating and checking the condition of fire extingnishers. Locating and checking the operability of the safety showers and eye fountain. Checking to make sure the exhaust hood system is operating properly. Locating and checking the operating condition of ntility lines, such as hot and cold water, distilled water, steam, gas, nitrogen, oxygen, electrical power, andsewer drains. Location of the main eot-off valves and switches to the laboratory should be known. All drains, valves, and fittings should be checked and requests snbmitted for repairs when necessary. University and State Codes require that only authorized mechanics are to repair or modify power and utility lines. For obvious safety reasons researchers are not permitted to work on power lines. Make an inventory of chemicals and apparatus. Arrange for discarding waste chemicals and obsolete apparatus. Arrange for the return of apparatus and equipment not needed to storage or storerooms. Inspect and clean all lockers, cabinets and benches. Cheek to see that the proper trash, chemical and solvent waste disposal containers are wailable. Make sure gas cylinder supports (chains or straps) are available. If needed place request for such.
Teaching Assistants assigned to an instructional laboratory for the first time are expected to make a like assessment in order to be prepared to handle emergencies. The teaching assistant should know: Location of emergency exits from the laboratory and building. Location of the fire alarm. Location of the first aid room. (Catinucd a page A601)
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Location and condition of fire extinguishers. Location and operability of safety showers and eye foundation. Location of power line and utility line cut-offs. Operating condition of exhaust hoods.
B. Working Alone Faadtv. mad~~", ~ostdoctoralfellows. and uate researchers may work alone in areas other than offices provided the following minimom safety criteria are met: ~~
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That the researchers presence is known to a second researcher located on the same floor within cslling distance. That there is little potential for a serious injury producing accident which would render the researcher helpless to cdl for assistance by voice, telephone, etc. That the researcher shall call the second person on the floor hourly and that the second person shall contact the lone worker immediately in the event he fails to call at the agreed time. When the experiment is such that there is a potential for a serious accident or one which may reach a condition by hecoming progressively worse, then a second researcher shall be immediately available for sssistance. To perform experimental work in a laboratory, an undergraduate student
must have authorization from his instructor. Under no circumstances is an undergraduate permitted to work alone.
C. Working at Night Except for regularly scheduled courses, all students and postdoctoral fellows must obtain authorization from their faculty advisor for %permitto workin the building after 5:00 p.m. Those requesting night permits must provide and keep in their assigned Jaboratory a flashlight for use in &event a power D . utility or pmerpailuTes To perform laboratory work safely it is essential that the worker include in his exDerimentd design provision for a ~oisibleutility failure which could cause an accident situation or an unsafe condition to develop. For example, in distillation operations loss of cooling water flowing through the condenser would develop an unsafe condition and result in a possible fire unless provision is made to cut off the source of heat to the still pat. Loss of power to vacuum pumps can cause serious damage to vacuum systems and expensive instruments unless the equipment design and operating procedures are carefully planned to meet such an eventuality. In the event of loss of power or a critical utility, the worker should quickly terminate his experiment, close down and evttcnate the laboratory. He should then inform his supervisor and report (Continued a page A603 )
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water. Refrigerators used for chemicals are not to be used for food or drink.
the s i t d i o n to the University security office.
G. Smoking
E. Unattended Operations Operations or experiments are not to he left unattended except for certain routine operations where antomatic safeties have been installed to effect shutdown in the event of loss in power and other utilities. Such unattended operations must be approved by the research supervisor. On an operation where permission has been given for unattended operation a t night, another researcher who will he present in the building must be informed of the operation with agreement to check it periodically. Always leave your telephone number where you may be reached in ca5e of an emergency.
F. Eating Preparation, storage, or consllmption of food or drink in chemical laboratory work areas is discouraged and should not he practiced because of the danger of contamination with toxio and poisonous substances. Before handling fond or drink or any other item which may he placed in the mouth, researchers should thoroughly wash their hands with soap and water to prevent ingestion of harmful materials. If the hazardous chemical is not readily solnble in soap and water, another effective safe solvent should be used, followed by washing with soap and
Smoking is not permitted in are= where flammable liquids, vapors or gases are heing or may be accidentally released to, the atmosphere. Also, smoking is not permitted in the vicinity of flammable liquid transfer operstio~~s.The safe distance from such an operation depends on vsriahles such as the quantity of vapor released, t,he air temperature arid the ventilation. Indoors the minimum distance is the confines of the room, while outdoors a safe distance is never less than 50 it. Before haeardons operations me started, temporary "No Smoking" signs shall be displayed in areas in which smoking is normally allowed. I n areas where smoking is permitted, suitable ash trays shall he provided by the SMOKER. Laying of burning cigarettes or cigars on benches, tables, ledges and the like or their disposal on the floor or in other waste containers is prohibited.
H. Repo~tingUnsafe Practices and Conditions Unsafe practices and conditions cause virtually all accidents. Immediate correction of potentid aocident cawes is a basic accident-prevention t,echnique. A person observing an unsafe act, practice, or situation should call it. to the attention of the researcher involved or his supervisor. (Continwed on pagc.A605)
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I . Reporting Accidents All accidents resulting in an injury, in property damage, or in a fire must be reported promptly to the instructor in charge or to the appropriate supervisor and to the Chairman of the Central Safety Committee. I n the event of an accident, the following steps should be taken: 1. I n ease of injury render prompt first llid doing only the minimum necessary to prevent more seriow injury to the patient. 2. If the accident occurs in an iwtructional laboratory, have someone summon help from the storeroom. 3. If injury appears serious have some one call an ambulance, giving room nomber and name of building. 4. I n case of fire:^ If small and easily extinguished select and use the laboratory extinguisher. I i fire is big or difficult to extinguish have someone call the fire department giving room number and building name and at the same time have someone sound the building fire alarm. Then proceed wibh an orderly evacuation. 5. For minor injuries send or t&e
the injured to the Student Health Center for treatment. 6. Report the accident promptly to your supervisor; also to the chairman of the Central Safety Committee.
7. Finally prepare
s. written report of an accident resulting in injury, property damage or a. fire.
J . Visitors Visitors ahall comply with all safety regulators in force in the place visited. Appropriate eye protection shall be worn hy visitors to any laboratory.
SP-2 Housekeeping (Removal of the hazard) The continuous practice of good house keeping is essential to the prevention of accidents, fires and personal injuries. Students working in laboratories are expected to keep their benches neat and orderly. A cluttered laboratory is a dangerous place in which to work; hy cleaning up after each step of an experiment a general housecleaning is necessary only occasionally. Each laboratory worker is responsible for: Keeping benches, tables, hoods, floors, aisles, and desks clear of all materials not being used. Keeping clear an adequate passageway to exits. Keeping clear space around safety showers, fire extinguishers, fire blanket? and electrical controls. Keeping floors free of spilled ice, dropped stirring rods, stoppers, pencils and other tripping hazards. Cleaning up spills and deposing of the (Continued on page A607)
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materials used to absorb the spills. Removing and disposing of broken glass. Using proper wastedisposal receptacles for solvents, glass, rags, paper, etc. Keeping chemical containers clean and properly labeled. Retaining only the quantities of chemicals needed for current work. Disassembling and returning to stomge surplus eqnipment. Hanging clothing in its proper place; do not drape over equipment and work benches.
SP-3 Handling Chemicals Chemicals can be hazardous unless properly handled. Serious skin and eye irritations and damage to clothing can result from needless spills and sprays. Toxic materials can cause severe illness, even death; all chemicals, %?peciallynew compounds, the toxicity of which have not yet been .determined, should be assumed to be highly toxic. Flammable gases, liquids and solids can cause fires and develop into explosive mixtures. Before working with any chemical, i t is essential to KNOW its properties. The properties of known rei~etion products, intermediates or even possible reaction products should be a3eertained before work begins. I n exploratory research work only very small quantities of chem-
icals should be employed. Larger amounts may be used after the initial work has been successfully completed and the reaction rates and the praperties of the reaction products have been established. Hazardous chemicals include, in addition to flammable materials, those substances which are toxic, corrosive. and/or reactive. I t mmt be recognized that a material, which by itself is comparatively harmless, can become very hazardous nnder conditions of use and under conditions t o which it may be subjected accidentally-as in t,he event of fire. A good reference for additional information on chemicals and their hazardous properties is the Handbook on Laboratory &jet& by Steere, published by The Chemical Rubber Company; each facult,y member has a copy of this handbook. A most important safety practice in the handling of chefnicals is to keep reagent containers properly LABELED. Containers of all substances in your laboratory shall be labeled showing: The chemical name and structure. The date of purchase, preparation, or transfer to its present container. The owner's name. A brief notation of hazard if any, a5 for example a ward like one of the following: toxic, corrosive, flammable explosive, and poison. Peroxides in common laboratory solvmts (Continued m page A609)
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are a frequent cause of laboratory explosions. Common solvents that peroxidize easily include: ETHERS--dioxme, tetrahydrofuran, ethylene glycol dimethyl ether (glyme), diethylene glycol dimethyl ether (diglyme), diethyl ether, diisopropyl ether; ALCOHOLSsome secondary alcohols, far example, is* propyl alcohol; HYDROCAILBONScyclohexene, also other olefins; tetralin, decalin, branched-chained saturated hydrocarbons, alkylsubstituted cycloaliphatics. Peroxide explosions occur most frequently during distillation or after the distillation has been completed and the operation is being shut down or dismantled. Distillations should be carried out behind shields. Research personnel are responsible for anticipating hazards associated with peroxidizable materials. Those working with such materials should avoid storing them over long periods of time because peroxides form readily in poorly closed containers or even in well closed containers if there is air apace above the solvent. Also, solvents should always he tested for peroxide content before using. Test methods and procedures for removing peroxides are described in the Chemical Rubber Company Handbook of Laboratory Safety (pages 190-194). Perchloric acid is especially dangerous because it explodes on contact with organic materials. Do not use perchloric
acid on wooden benches or tables. Keep the perchloric acid bottles on gla3s or ceramic trays having enough volume to hold all the acid in case the bott,le breakr. Discolored acid (contaminated) should be disposed of immediately. Gently pour the discolored acid into a beaker or porcelain jar which contains a t least one volume of cold water for each volume of acid. Mix gently and pour the diluted material down a drain with large amounts of cold water. A speeid hood is required if an operation is carried ont in which the acid is heated to f ~ m i n g . S w h fuming operat,iann are forbidden in ordinary hoods. Experiments involving tozie and carrosive vapors should be carried out, in fume hoods. In general, when working with m a l l quant,it,ies of such mst,erials the hood exhaust. volume is sufficient to prevent an atmospheric pollotion problem above and out,nide the bnilding. When large scale operations are carried ont in fume hoods whirh evolve large amormts of either flammable, corrosive, or toxic vapors, these vapors should he treat,ed to destroy the harmful effects and thereby prevent at,mospheric pollut,ion o ~ h i d ethe building. For example: Condense flammable vapors and then dispose of the condensate. Absorb halogens and like materials in an appropriate reducing xgent and flush the resukinp solution to the sewer. (Conlinuwl on page A f i l O )
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Absorb HCN in an alkaline oxidizing agent, sllch as Clorox, and flush the solution to the sewer. Unused chemicals ~houldnot be allowed to accumulate in s, laboratory. All reagents should he inspected periodically and ihase not needed removed. Dates on labels of materids that may form hazardous suhstances on prolonged storage should be checked periodically. The total amount of volatile, flammable solvents stored in a laboratory shodd not exceed ten gsllons. Whenever corrosion or contamination is not a factor, store solvents in excem of one gallon quantities in metal containers, and store low flash point liquids in standard safety cans. Limit quantities of solvents in glass bottles to one gallon; store glass bottles of solvents in closed metal cabinets. Because of the danger of fire, low-flash liquids and gases under pressure should not be stored close to sources of heat such as radiators, hot-plates, ovens, etc. Also keep cloth and paper towels away from heat sources. Listed below are a few simple but important reminders of precautions that should be considered in the routine handling of reagents. Keep reagent containers clean on the outside to protect your hand; use rubber or plastic gloves when appropriate.
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Be sure rubber gloves are clean on the inside before using; cleanse or decontaminate gloves regularly. Avoid prolonged contact of chemicals with skin; wash hands and face frequently; be sure laboratory clothing is cleaned regularly. If water is not the appropriate washing agent, or antidote, procure proper first aid supplies before starting work. Avoid inadvertent contamination by not returning unused portions of reagents to stock battles; stoppers should be held while pouring. Never taste a chemical. Smell cautionsly--sniff (never inhale). Use a safety pipet filler, (pipeting by mouth is dangerons). Cool sealed vials of chemicels below the bailing point of the snbstance contained therein before breaking seal. Cool gradually, first in ice water, then COS et,c., to avoid temperatme shock to the glass vial and a possible explosion. Add concentrated chemicals to water (never vice versa). Keep flammable solvents such as benzene, ether, etc. away ffom hot plates and flames. Use care in transporting chemicals; never carry more than two at a time by hand; carry large bottles in bocketa or safety carriers. Use caution in working with mercury. The equilibrium concentration of Hg vapor over liquid mercury at room t,emperatr~reis approximat,ely 20 times the threshold toxic limit,.
Clean up spills of mercury and other chemicals promptly. (See page 239, Chemical Rubber Company Handbook of Laboratory Safety for the method of cleaning up mercury spills). Know the locations of safety showers, eye washes and know how to use them.
SP-4 Chemical Waste Disposal Responsibility: In the instructional laboratories the disposal of unused and waste chemicals is incorporated as an integral part of the course and specific instructions are given on methods of handling and disposing of waste products. In the research laboratory, where many unusual and specific chemicals are used, the responsibility for disposal of unused reagents and waste reaction products is vested directly with the researcher m d his project supervisor, because, in most cases, it is only the researcher who knows how to h m d e the materials safely. In either case, waste chemicals should never be deposited in waste baskets or other trash containers, but rather should be disposed of by one of the iollowing general procedures. Water-Soluble Wastes: In general, small quantities (100 ml. or less) of water soluble chemicals which do not hydrolyze to form volatile, toxic, or odoriferous materials may be flushed down the drain with copious quantities of water. Corrosive materials in minor quantities such as acids and alkalies should be diluted with large quantities of water and then flushed (Continued on page A612)
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- ~- - down the drain. Lhrge quantities of waste acids, bases, and chemicals, which hydrolyze to farm corrosive and haaardaum products, should be treated to render them harmless before flushing to the sewer. In general, hazardous chemical wastes should be subjected to a process in the laboratory whirh converts them into harmless products not requiring special handling. Flammable Lipuid Wastes: Flammable liquids not miscible with water must not be poured into the sink or other sewer drains. Law flash point flammable wastes and solvents should be placed in safety cam and transferred to the wayte solvent storage located outside the building. Waste solvents containing materials in soh~tianapt to farm toxic or corrosive substances or hydrolysis, oxidation, etc. shodd first be treated to render them harmless before transferring to waste solvent storage. Water-insoluble Solids and Na-$ammable L i p i d s : Those materials which can be stored safely aver a period of time, without deterioration should he kept in their original containers and taken to a central disposal area where they may he destroyed by borial, burning, or some other effective means. Emplied Chemical Catainers: Before discarding, all empty chemical containers must he rinsed. Rinse containers for organic reagents first with acetone and then with water. This practice prevents
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subsequent injury to those handling the discarded containers.
SP-5 Handling Compressed Gas Cylinders (Safe Technique) Compressed gases impose potential hazards on the laboratory worker if not properly handled. Such gases can be used in the laboratory with safety if the following precautions are compiled with completely during cylinder reoeiving operations, storage, transportation, usage, and empty cylinder disposal. Know the cylinder contents and its properties: The physical properties, flammability, corrosiveness, and physiological (e.g. toxicity, anesthetic, and irritating) properties of a cylinder gas should be known before it is used. If the contents of s cylinder cannot he determined completely from wording on the cylinder or s n accompanying tag attached to the cylinder (not its cap), mark the cylinder "unidentified" and return to the supplier. Do not rely on cylinder colom, whichvary from company to company; some people are colorblind. Never remove or deface a label. Handling of cylinders: Cylinders are built as light weight as possible as is consistent with safety and durability for use as shipping containers. They therefore should be transported carefullylarge cylinders only with a wheeled cartand fastened securely with a strap or chain before removing the cap. Abwe and hard knocks can seriowly weaken a container, and a falling cylinder can
break legs and crush feet. Finally, should the valve be broken, the cylinder becomes a powerful rocket. Healing of cylindomr Most cylinders are equipped with fusible metal safety plugs which release if it is heated above 70°C. Therefore, if it is necessary to warm a cylinder to facilitate discharge of the contents, immerse no more than the lower 20% in warm water; steam should never be used directly on a cylinder. The valve must be partly open whenever a cylinder is warmed. Use of valves and regulators: A cylinder is alway~used with a regolator selected specifically for the given gas. The threads of the regulator will match the threads of the cylinder outlet. If the connedion must be forced you have either the wrong regulator or the wrong gas. To remove gas through a regulator, first eusure that all valves are closed, then soccessively and slowly open all valves, starting with the cylinder valve. Be sure that the final valve opening directs the Raw of gas away from you and others, and always wear safety glasses or goggles. Close all valves and in the same order as before. Since cylinder valves, partieularly those used with corrosive gases, are designed so that the valve stem and packing are protected from contact with the gas when the valve is either completely open or closed, it should always be in either of these two positions. The cylinder valve should be closed when gas is not in use. (Continued a page A614)
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Control qf gas and reaction system: To prevent contaminants from entering the system, always place a trap between the cylinder and the system; and to prevent an explosion revulbing from suck-back of contamination into the cylinder, never completely empty the cylinder. If pressure may boild up in the system, equip the line with a pressure indicator and a safet,y vent,. Handling of empty cylinders: The valve shonld be closed and the cap replaced on empty cylinders. They shanld be marked with "MT" and dated, and then returned to the supply center. Do not attempt to refill a cylinder. RepaZr and adjustment of equipment: Do not attempt to repair a regulator yourself. Also never attempt to tighten nuts or balk on fittinm of high pressure equipment while it is in use. Release the pressme first, then make adjustments.
SP-6 Handling Equipment and Apparatus (Safe Technique, Judgment) Any material, be it a. chemical, a p paratus, an item of forniture, a fixture. . ., e m present a hazard, start a fire, or cause injury if not properly handled. You can remove or minimize the hazard with proper handling. Some of the precautions in handling common laboratory equipment are listed below:
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Equipment location: Locate equipment set-ups as far back from the bench edge as possible, and be sure that the center of gravity of the apparatus is within the base area. Use ring stands properly. High-pressure Apparatus: Inspect all pressme equipment carefully before using and establish the limitations of the equip ment with respect to temperature, pressure, and capacity. Be certain that the system is equipped with a safety relief valve and that it is operative. Introduce compressed gas from cylinders slowly and cautioosly into the system, making certain that there is adequate shielding between you and the pressure gauge. Remember to reduce the internal pressure to atmospheric pressure via the relief valve before you open the pressure vessel. Reduced-pressu~esystems: Many of the precautions for use of high-pressure equip ment applies equally here (e.g. limitations and inspection of equipment, provision for capillary relief valve, turning vacuum lines on (or off) slowly, examination of pressure gauges). In addition, raundbottomed flasks should be used for low pressure reactions, and vacuum pumps should be protected from corrosive gases such as halogens, SO. HCI, etc., by placing appropriate traps in the system. Mechanical s~stems: Avoid personal injury by protecting or covering pump shafts, moving belts, etc. from towels or clothing, using explosion-proof motors and switches on operations in meas ex: posed to flammable vapors, and by grounding d l appmatus with either 3prong plugs or pigtail adapters. Turn
off motors on which liquid has been spilled, and use again only after they have thoroughly dried inside and out. Electrical assemblies: Avoid daneerous makrrhifr wiring nusmrldir.: by l.aviug prrmnumt wiring (either w n h i t or B S m l d r i inctnllrrl 1," nn elrrtririnn. Replare immediately worn extension cords or cord with thinning insulation. Never handle any electrical connections with damp hands or when standing in or near water, and be wary of static accum~~lations, especially in high voltage situations. SP-7 Handling Laboratory Glassware (Safe Technique) If not properly handled, glass apparatus can be a serious hazard to the chemist. These hazards can be minimized by exercising certain precautions: Handling glassware and tubing: Always carry glass tubing or rod in a vertical position. Protect your hands with a cloth towel or with gloves when cutting or breaking tubing, and fire polish immediately sharp edges of all glassware. Test glassware for strains, and when necessary remove strains by annealing. Inserting and removing tubing and stopcocks: Lubricate, using water or glycerine, the surface of glass tubing before inserting into rubber tubing or stoppers. When working such connections, protect your hands with gloves or a towel, and keep your hands close together. Use the same technique to remove glass tubing from rubber tubing or stoppers, and never use (Catinued a poge A616)
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great force. If necessary, a lubricant can be worked between the rubber and the glass with the neck of a file. Frozen stoppers or stopcocks should be removed with a stopcock lifter. Using vacuum glassware: Protect yourself from flying glassware in the event of an explosion or implosion whenever glass apparatus under pressme or vacuum is used by employing a safety shield. Additional protection can be gained by wrapping vacuum desiccators and Dewar flasks with electrical tape. Remove the cover of a desiccator with caution, after the pressure has been equalized, by sliding the cover to one side; do not lift. If the lubricant on the groond-glass surface has hardened, soften it by gentle warming with hot water. Disposing of broken glassware: Glassware should always be washed before it is stored or diucarded. Remove broken glass fragments from desk taps and floors with a brush (never your towel!), placing i t in the proper disposal can; never store broken or fractured glass in your locker.
oxidant away from the hot ignition source. The major somw of heat in t h e laboratory are: 0 0 0 0 0
The major source of oxidant is, of course, air, (oxygen); however, other oxidizing agents can supply the oxidant. Sourca of fuel are: 0 0 0 0 0 0 0 0
To start a fire three components must be present; you m w t supply a fuel, an oxidizing agent, snd a source of heat far ignition. Many fires can be avoided if the worker simply keeps the fnel and
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Woad Painted surfaces Towels, oily rags Paper and books Hair and clothing Gases (methane, hydrogen) Flammable solvents Many other chemicals or dusts thereof
The storage and handling of volatile flammable liquids requires that certain precautions be taken t o minimize the fire hazard. The inherent fire and explosion hazard depends not only on the flash point of the fuel but also on its ignition temperature, explosive range, and vapor density.
SP-8 Fire Prevention (Judgment, Safe Technique)
Matches The bunsen burner Electric hot plates Electric sparks Steam hathq
0
0
The flash point of a fnel is the lowest temperature a t which it volatilizes fsst enough to form an ignitable mixture with the air surrounding the flash apparatus. The ignition temperature of a material, whether d i d , liquid, or gaseous, is
the temperature required to caux sufficiently rapid oxidation to be selfsustained when the hot ignition source is removed. The explosive range of a fuel refers to the definite limitatiana of combwtibility and rate of burning of the flammable vapor or dust mixture in air. The mixture iri "too lean to burn" when the particles are so widely separated that those set afire by the hot ignition source will not set fire to others that are nearest. The mixture is "too rich to burn" when the particlea are so close together that they exclude the oxygen necessary for combustion. The concentration between the "leanest" and "richest" mixtures that will burn is called the explosive range. A flash jire results from very rapid oxidation and occors only when: The foel iil mixed wit,h sufficient oxygen for complete combustion. The particles of fuel vapor or dust are suspended in a diffused atate in air, close enough to each other to propagate the fltlme through the vapor or dust and still s~tfficiently separated t o make room for the r e qnired amount of oxygen for eamhustion. A source of heat equal to t,he ignition temperature is present,. To avoid 8 flash fire keep the fuel s t s. temperature below it,? flash point, and keep it away from hot swfaces t,hat asre (Calinurd a page 14618)
above the ignit,ion temperatwe. Remember the vapors having a density greater than air will flow downward to t,he hut plate whereas t,hose less dense than air will flow upward. A fire is extinguished hy applying the same principles followed in trying to avoid it. Reduce t,he air sopply by smotheringcover the vessel or apply CO*. Shut off or reduce the fuel supply. Cool the fuel below its ignition tcmperatore. Lower the concentration of the fuel by dilution with an inert material.
Tgpe of Fires Class A: burning wood, paper, cloth, etc.; extinguished with water, foam, soda-acid, or C01. Class B: hwning oils, greases, paints, etc.; extingnished with foam, COz, or dry ohemical. Class C: live electrical equipment; extinguished with COXor dry chemical. Class D: active metals s w h as sodium, potassium, aluminom; magnesium, lithium, d s o diborane, ete.; extinguish by smothering with dry soda ash, dry sodium chloride, sand (never use water, foam, CO? or CCL). The following safe practices must he known and observed to prevent or handle a fire:
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See that corridors and stairwells aye kept clear; avoid placing chemicals, equipment, furniture therein. See t,hat fire doors are kept closed a t all times. Know the location of fire-blankets, safety showers, sand buckets, and fire exting!lishers. Know how t,o operate fire extingr~isherp. and t,he type of fires for which they are to be used. If a fire ocews, first get a fire CXtinguisher, t,hen after assessing t,he situation extinguish t,he fire, render assistance, or get additional help. Never retl~rnan empty or partially used extingrdnher to its rack. Tag it empty and deliver i t to the storeroom and have it replacod. All fires for which an extinguisher is used or which cause damage or injury must be reported. If your clothing should catch fire, try to stay calm, don't nm, hut quickly get nnder a shower and keep the water rrmning. Or wfap yourself in a fire blanket. Yell for help. If a fire cannot he sn~~lTed oilt immediately, have someone sound the building fire alarm and call the fire department. Give name, building nnd room number.
Accident Repori Formal To report a n accident which results in an injury, property damage and/or a fire, simply write a concise letter t o the Central Safety Committee chairman giv-
ing the following information:
1. The name, address and phone number of The person(s) experiencing the accident The person(s) injured 0 Witnesses, if any 2. The place of the accident Building Room number Lacation in room 3. If accident occurred in an instruetiand course, list The oourse numher and section 0 The name of the teaching assistant The name of the faculty member in charge 4. If accident, occurred in a research group The name of the preceptor 5. Give the date and timeof the accident. 6. Describe briefly, but sequentially, all the known facts concerning events leading up to and following the accident,. These fact8 may be established with participants or witnesses. Avoid opinions and eonelusions. 7. If the accident resulted in injury, describe briefly the nature and extent of the injury, the type of first aid rendered and by whom, whether the injured was sent or taken to the infirmary or hospital, whether or not. an amlmlsnee war called and used, and the time involved. Also indicate t,he conditions of the injured after (Continued on page A620)
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treatment,. 8. If the accident resulted in a firc, how was the fire extinguished, was the fire alarm sounded, was the fire department called, how soon did t,he fire department arrive, and, if hand fire extinguishem were wed, were they submitted for refill? 9. If the accident resulted in property damage, describe briefly the extent of damage. 10. The name, address and telephone n ~ ~ m hof e rperson p~.eparingtho report if someone other than l i s t d under item one above. 11. Show a copy of the letter to yotu supervisor.
CHEMISTRY
DEPARTMENT S A F E T Y ORGANIZATION Choirman
Instructional Supervisor
Supervisor
Preceptor
Representative
Representative
Representative
Chemistry Depaflment Safety Organization
To achieve its objectives the operations in the department are broken into manageably sized groups depending on t,he size and complexit,y of a given f~mction. In the area of instr~tctiona grotrp can he either a division, a lect,ure section, a laboratory section, a seminar, or a colloquium. In the area of research the group comprises all those working wibh a given preceptor. Slipporting services such as lecture demonstrations, storerooms, shops, are divided by groups. The way these various groups are aligned in the department's organization for safet,y is shown in Figure 1.
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Students
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F i g u r e 1. 1 . Respasibilily for Safety: Each memher of the Chemistry Department is 8. member of the safety team; this includes all employees as well as postdoctoral fellows, gradoate and undergraduate stndents associated with ihe depart.ment. Each is responsible to the department through the line organization. Primary responsibilily is placed on the individ-
nal doing the work. For example, the student, the craftsman, or the researcher is responsible to his supervisor or preceptor for doing his work safely. In turn, the teaching assistant, the instruo tor, the service supervisor, or the preceptor (as the case may he) is responsible to his nupervisor, who in turn is responsible (Continued an page A622)
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to the Chairman and to the Dean of the College. 8. Central Safet?, Committee: Members of the committee representing major work areas in the department are appointed by the Department Chairman. The committee in respamible for: 0
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Establishing department safety policy. Promoting uniform safety practices. Fostering good rommnnieation in safety Reviewing the department's safety program. Reviewing the department's accident experience. Reviewing projects from a safet,y viewpoint as required. Conducting departmental safety inspect,ionr; a t intervals. Assessing department's safet,y pratection equipment. Formulating the annual s8fet.y budget.
5'. Deparlment Safely Coordinalor: The Chairman of the Central Safety Committee sewes as safety coordinator for the department. His duties as safety coordinator include: 0
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Developing a safety program far the Department. As~istingthe safety representative of the various research groups to develop safety programs. Receiving accident reports.
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Seeing that safety mt~tterscommon to the entire Department are handled in a uniform manner. Coordinating contacts with other departments. Issuing department safety reports. Maintaining a library of safety pvblications and safety data ~pplicahle to the department's activities. Circulating safety information as required within the department. Representing the department on accident investigations.
4. @OUP Safety Representative: The snpervisor of each operational group in the department is responsible for the safety program within that group. To assist in discharging this responsibility, he may appoint a member of his group to serve as safety representative. On the other hand, the supervisor or preceptor may elect to serve in t,his capacity himself. The primary dnties of the safety representative include: 8 0
0
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Development of a safety program for his group. Consultation on matters pertaining to safety. Establishing procedures to handle emergencies. Reviewing new or modified practices. Reviewing dcqign and construction of new and modified experimental units. Investigating and arranging for reporting of accidents.
6 . Teaching Assistant Duties and Responsibilities for Safety: Tho strength of the department's safety program depends on the performance of its teaching assistants in the undergraduate instructional laboratories. By his actions and example the teachiug assistant develops students with safe working habits. By so doing he strengthens his own safe working habits and acquire8 an alertness to the hazards of the chemistry laboratory. These habits carry over to his own graduate research work. A few guide lines regarding the Teachlng Assistant's duties with respect to safety are: 8 0
0 0
8
Teach and enforce safety as an integral part of the coitrse. Make and see the students make a careful analysis for safety before starting an experiment,. Srich a n assessment inclodes: -Collecting pertinent information -Foreeating potential hazards -Selection of safe techniques -Use of protective equipment -Plan of action in case an ~~nanticipated accident occurs
See that safety rules are obeyed; set a good example yourself. Remain in the laboratory a t all times when students are present; have someone else in charge if you must leave. Know the location and use of the protective equipment provided. (Conlinued on page A624)
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In care of an accident or illness: -1lender prompt first aid. -Have someone report to the course storeroom for help. -If injury or illness appears serious have someone call for an ambulance. -1teport all accidents that cause injury, no matter how minor, immediately to your supervisor and the chairman of the Central Safety Committee. -Prepare a written report on all accidents that cause injury. I n oase of a fire: -If small and easily extinguished select and use the laboratory extinguisher a t once. -If fire is big and difficult to extinguish have someone call the fire department and sound the fire alarm. At the same time proceed with an orderly evacuation of the building. -Take all fire extinguishers that have been used to the course storeroom for replacement. Tag such extinguishers as empty. -Prepare a report on all fires that crtuse damage or injury. Inform supervisor and the chairman of the Central Safety Committee. The ezcerpts in this column are from the SAFETY HANDROOK used only by the Ohio State University Chemistrv Depwtm a t , and are printed with permissia by the Chemistry Deportmat of Ohio State U n t k s i t y , Columbus, Ohio 45210. The authors may be contacted if there are specific inquiries. ~
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ANOTHER PAIR OF EYES SAVED BY SAFETY GLASSES As chernirtmmipuloted the apparatus to remove the first fraction in the purification of 8 groms of 2-methoxy-2-hydroperoxy-propane, the distillation flask exploded. The safety glorser pictured below on the damaged thermal magnetic stirrer protected his eyer.
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