Safety In Chemistry ] Introduction Students have a duty of care to minimize and eliminate chemical risk and hazards through proper use of laboratory equipment and to be prudent of potential dangers associated with their use. Regardless of whether you are using heat or flames to observe physical and chemical in the laboratory, you cannot assume that you already know and understand the hazards of working with laboratory burners without proper orientation. Reviewing the safety rules every time you work with reinforce safe laboratory practices, increase safety awareness, and reduce the risk of accidents. Identified Risks and Hazards Toxic effects of chemicals if they enter the body chemicals can enter the body by being swallowed, inhaled, absorption through the skin or cuts in the skin. Corrosive effects of some chemicals if they come into contact with the skin (a corrosive material is a highly reactive substance that causes obvious damage to living tissue). Some chemicals may cause respiratory and skin sensitization. The highly flammable nature of some chemicals. Copyright 2010 OnGuard Safety Training PTY LTD 1
Some chemicals can react violently with other chemicals if they come into contact with each other. Top Pre- operational Safety Eye Protection It is recommended that eye protection ALWAYS be worn in the laboratory. The need for adequate eye protection is fundamental to the use of chemicals. Eye protection, and at times face protection, is required wherever the potential for eye injury exists. Splash goggles with splash proof sides or a face shield must be used when protection from a chemical splash is needed. Face shields afford protection to the face and neck. Safety glasses with side shields for dust and flying object protection Use of Respirators Respirators are designed to protect only against specific types of substances and in certain concentration ranges, depending on the type of equipment used. You should familiarize yourself with the limitations of each type of respiratory protective equipment used and the signals for respirator failure (odor breakthrough, filter clogging, etc.). Protection of Skin and Body Skin and body protection require protective clothing and include protection of various parts of the body either completely or partially. Caps should be worn to protect hair from contamination. Operating Safely Top Copyright 2010 OnGuard Safety Training PTY LTD 2
Inspect equipment or apparatus for damage before adding a hazardous chemical. Do not use damaged equipment. Remove all flammable and combustible materials from the lab bench and surrounding work area when Bunsen burners will be used. Do NOT use a Bunsen burner in any lab when working with flammable liquids or solvents. Do not force glass tubing into rubber stoppers. Use glycerin as a lubricant and hold the tubing with a towel as you ease the glass into the stopper. Proper procedures shall be followed when using any heating or flame producing device especially gas burners. Remember that hot glass looks the same as cold glass. Never leave a flame unattended. After heating, glass remains hot for a very long time. Determine if an object is hot by placing your hand close to the object but do not touch it. Should a fire drill or other evacuation emergency occur during an investigation or activity, make sure you turn off all gas burners and electrical equipment and exit the room as directed. Electrically ground containers using approved methods before transferring or dispensing a flammable liquid from a large container. Use hazardous chemicals only as directed and for their intended purpose. Never smell, intentionally inhale or taste a chemical. Keep chemicals off your hands, face and clothing, including shoes. Avoid direct contact with any chemical. Always wear a laboratory coat, at a minimum. Keep your hands and face clean. Wash thoroughly with soap and water after handling any chemical and whenever you leave the lab. Handling Solids Copyright 2010 OnGuard Safety Training PTY LTD 3
Student must wear proper protective equipment in handling solid chemicals since it will predispose them to same risk and hazards from liquid chemicals. Heating Beakers and Test Tubes Use care when working with hot glass. Hot glass looks exactly the same as room temperature glass. Do not leave hot glassware unattended, and allow ample time for the glass to cool before touching. Check the temperature of the glassware by placing your hand near, but not touching, the potentially hot glass. Never point the open end of a test tube toward anyone. Never look into the open end of a heated test tube. Test tubes should be held with a test tube holder and heated gently along the side, not at the bottom, to minimize superheating. Any set-up should be designed to allow for fast removal of the heat source. Do not clamp test tubes or beakers more tightly than necessary to hold them in place when heating. Expanding glass may break if clamped too tightly. Have hot pads, thick gloves, or beaker tongs available for grasping hot beakers. Mixing Substances Copyright 2010 OnGuard Safety Training PTY LTD 4
The order of mixing chemicals is important. Follow the instruction by your supervisor properly. Changing this order will not only affect the readings, but also can cause fast reactions leading to an accident. Use of MSDS Be sure to read the MSDS because they provide the information needed to protect users from any hazards that may be associated with the product. MSDS have become the primary vehicle through which the potential hazards of materials obtained from commercial sources are communicated to the laboratory worker. Spill Kits Check the location of the Spill Kit and that a copy of the MSDS for the concentrated acid being used is available working with concentrated acids Remember to slowly pour acid into water, never water into acid. Every preparation area should have a spill kit for emergency. Copyright 2010 OnGuard Safety Training PTY LTD 5
All staff including teaching staff should note where it is stored, they should also be informed of the contents and how to use it. Concentrated acids Concentrated acids are only allowed to be handled in the fume hoods. Filling and rinsing of the bottles should only be done near a sink, but with secondary containment tray in the sink. It is essential that you wear a face shield over your safety glasses, nitrile gloves (preferable), and the neoprene aprons to ensure proper protection for concentrated acid spills. When pouring the acid, pour the acid into a clean beaker, then pour the acid from the beaker into a graduate cylinder. Always pour the acids inside a secondary container in case of a spill. Remember always pour acid into water slowly Once the acid has been dispensed; properly label the bottle using the safety data label. Wash any glassware which was used with the acid, rinse them 3 times with distilled water, and collect the first three washes as hazardous waste and dispose appropriately. Maintenance Storage of chemicals Smoking, drinking, eating and the application of cosmetics is forbidden in areas where hazardous chemicals are used or stored. Follow general precautions which must be observed during storage of chemicals from the chemical safety data (MSDS). Try to store only the minimum possible amounts. Top Copyright 2010 OnGuard Safety Training PTY LTD 6
No unauthorized person should be allowed access to the chemical store. Some chemicals are sensitive to moisture, others to sunlight, some to heat, still others to shock. This should be kept in mind while allocating area for storage. All containers being stored should be properly labeled. Firefighting and personal protective measures should be readily available in chemical storage areas. Do not store incompatible materials near each other; they may react and cause safety and health risks. Disposal Do not return unused chemicals to the reagent container. Follow the supervisor s directions for the storage or disposal of these hazardous materials. Hazardous chemical disposal must be according to procedures established by the relevant authorities. All materials contaminated should be disposed of as hazardous waste. For spills or leakages of hazardous liquids, absorbing material like sand, clay, wood dust, chemical powders, etc. are used to absorb the spill and then disposed as solid waste or incinerated. Waste bottles Solid chemicals, metals, matches, filter papers, broken glass, and other materials designated by the supervisor are to be deposited in the proper waste containers, not in the sink. Follow your supervisor s directions for disposal of waste. Hazardous solid waste and waste with long life must be given special attention. Copyright 2010 OnGuard Safety Training PTY LTD 7
Glassware should be disposed of in a separate container from normal trash and it should be clearly labeled 'BROKEN GLASSWARE ONLY'. When handling broken glassware, wear gloves or use a dustpan and broom. Do not pick up broken glass with bare hands. Top Operating Procedures Labels Always read the reagent bottle labels twice before you use the reagent. Be certain the chemical you use is the correct one. Chemicals must only be kept in containers that are clearly labeled and have been designed for that purpose. Materials purchased from suppliers should already be correctly labeled. Containers which chemicals are decanted into must be clearly labeled. Keep the labels intact for it is the primary source of information about the identity, safe use, disposal and health and safety measures to be taken during the use of chemicals and in case of emergencies. Existing labels on new containers of chemicals or containers in storage shall not be removed or defaced. Read labels before working with any chemicals hazard information should be provided with all unlabeled chemicals in student laboratories. Carefully read all the information on the label. If you do not understand something, contact your supervisor for an explanation or request the MSDS. Hotplates Use a hot plate with a smooth, clean surface. Copyright 2010 OnGuard Safety Training PTY LTD 8
Hot plates appear exactly the same whether hot or at room temperature. Always assume they are hot and act accordingly. Keep the electrical cord of a hot plate away from water and the heating surface. The cord of the hot plate should be checked periodically for frays and faults. Any hot plate with faulty wiring should not be used. It should be repaired or replaced immediately. Do not place hot apparatus directly on the laboratory desk or bench. Always use an insulating pad, and allow plenty of time for hot apparatus to cool before touching it. Pipettes Never put a pipette in your mouth. Draw the liquid into the pipette using a rubber bulb or pipette pump. Never withdraw a liquid from a near-empty container. If you attempt to fill a pipette under conditions where air can enter the pipette, the liquid will shoot up into the bulb or pump. Never lay a pipette flat on a table or turn upside down with the bulb or pump attached. The liquid will flow into the bulb/pump, contaminating the bulb/pump. Dispose of broken pipette in the appropriate glass-disposal container. Thermometers Copyright 2010 OnGuard Safety Training PTY LTD 9
Never use a thermometer as a stirring device. Never swing or shake down a thermometer. Never use an open flame on a thermometer bulb. Use extreme care when inserting or removing a thermometer from a rubber stopper. Mercury thermometers should not be used in heated ovens where breakage might easily occur. Don t place thermometers where they are likely to roll or be knocked off a table. All thermometers should have anti-roll devices. Make sure you choose a thermometer with an appropriate temperature range. Overheating a thermometer can cause breakage of its reservoir. Fume Cupboards Make sure that the exhaust blower is operating and air is entering the hood, prior to starting an experiment. Do not place your face inside the hood. Keep hands out as much as possible. Perform all work involving hazardous or volatile materials in operating fume hoods. Copyright 2010 OnGuard Safety Training PTY LTD 10
Connect all electrical devices outside of the hood to avoid sparks which may ignite a flammable or explosive chemical. Note that the hood is not a substitute for personal protective equipment. Always work at least 150mm in from the opening of the fume hood. Do not modify the fume hood. Do not use the fume hood as a storage area Avoid blocking off baffle exhaust slots in any manner. Elevate large equipment 50mm off the base of the fume hood. Large pieces of equipment or numerous persons standing in front of the fume hood will cause turbulence. Be aware of other room ventilation factors that may interfere with your fume hood operation, such as open doors to labs, open windows, blocked exhaust ports or heating and air conditioning vents. Prepare a plan of action in case of an emergency, such as a power failure, especially when using extremely hazardous chemicals or acids. Work with the sash at the proper operating level as indicated by the arrows. When fume hood is not in use, keep sash closed. When fume hood is not in use, ensure that all materials are in sealed containers. Copyright 2010 OnGuard Safety Training PTY LTD 11