ANU Lab Safety 2024 PDF

General laboratory Information By the end of this section you should be able to Identify different laboratory instruments and apparatus and their uses. Identify different laboratory hazards  identify causes of each hazard  Precautions when dealing with this hazard to mini...

General laboratory Information By the end of this section you should be able to Identify different laboratory instruments and apparatus and their uses. Identify different laboratory hazards  identify causes of each hazard  Precautions when dealing with this hazard to minimize accidents  First aid measurements in case of accidents Contents Laboratory Instruments Laboratory Hazards Laboratory Instruments and Apparatus 1- Instruments used for volume measurement -Laboratory Instruments used for volume measurement depend on the accuracy and volumes needed. -The smaller the diameter of the instrument the more accurate it would be  1.Instruments used for volume measurement Glass Used to transfer small- volumes of liquids (1ml- graduated 10ml) Pipette pipettes s Most accurate of all, Automatic used to transfer micro- pipette volumes of liquids e.g. (1μl-1000μl) Instruments used for volume measurement Automatic pipette Glass graduated pipettes  Careful use of Automatic pipettes Place the plunger at the end of its stroke before inserting the pipette tip into the solution to be taken, thus avoiding the formation of bubbles in the solution. Note the two stops on the piston stroke. The first stop (offering slight resistance to the finger) indicates the exact volume to be taken. The second stop (extra stroke) is only used to expel the entire liquid. Gently return the plunger to its original position after loading the solution to prevent air bubbles from entering the pipette tip. the sudden return of the plunger to its original position can draw liquid into the pipette, which can damage the mechanism. Instructions!! 1 2 3 4 Do not invert or Do not knock or Do not touch the Dispose of used tilt the pipette drop the pipette tip with tips in the excessively pipette. your fingers, as containers when it is filled this may provided for this with liquid. contaminate the purpose on all solution. tables. Volumetric flasks A volumetric flask is used for the preparation of solutions with different concentrations and volumes.  Graduated cylinders A graduated cylinder is used to measure different volumes of liquids. How to interpret the volume of a solution? 2. Instruments for transfer, mixing, boiling and storage of chemicals Test tubes Used for performing chemical experiments and reactions in lab, e.g. Holding liquid samples for heating, dissolution, centrifugation, and others. Reagents and chemicals bottles Used for storage of different chemicals, reagents, and even strong corrosives. So, they should always carry an informative label.  Graduated beakers Used for rough estimation of solution volume and for mixing different reagents  Conical (Erlenmeyer) flasks More accurate than beakers in measuring volume of solutions.  3. Instruments for handling of chemicals Spatula It resembles teaspoons. It resists corrosions. It is used to handle solid powdered  Pipette pump It is inserted into the end of the glass pipette to help the delivery of liquid without suction by mouth.  Droppers & plastic transfer Pasteur pipette They are used to transfer small amounts or drops of liquid solutions.  4. Other lab tools and equipment Test tube Rack Test tube racks are for holding and organizing test tubes on the laboratory counter. N.B plastic racks may melt from very hot test tubes Test Tube Holder A test tube holder is useful for holding a test tube which is too hot to handle.  Bunsen burner Used for the heating of non- volatile liquids and solids.  Lab water bath Water Bath provides precise temperature for lab reactions control.  Funnels A funnel is used to aid in the transfer of liquid from one vessel to another.  Balance Used to weigh chemicals.  Centrifuge Spins liquid samples at different high speeds to sediment different fractions. Q: How to determine the volume of fluid in the following cylinders? A: The volume is determined from the bottom of the  General laboratory information DO NOT work alone in a laboratory. Know the location and proper use of fire extinguishers, eye wash devices, and first aid kits. DO NOT perform unauthorized experiments. - Always wear your lab coat. - No eating or drinking inside the lab. - No bags or personal items and NO SITTING on the lab benches. - When in doubt…ASK YOUR INSTRUCTOR. - Listen to your instructor carefully and stand in your proper position in the lab.  Laboratory Hazards 1- Biohazards Laboratory 2- Corrosive and caustic hazards chemicals; -Strong acids -Strong bases - Poisons. 3- fire and explosions 4- electrical hazards. For each hazard:  Causes and examples.  Precautions  First aid 1-Biohazards: Human clinical samples are biohazards, as they may carry viruses or bacteria. The risk is accentuated by pipetting with the mouth, the presence of wounds on the skin or mucous membranes, and contamination of the hands.  Biohazards: prevention The risk can be minimized by: Using automatic pipettes, a mask, and gloves. Samples must be properly labelled and disposed of together with other materials that has been in contact with them in special containers. 2- Chemical hazard: Corrosive and poisonous chemicals  causes A) Strong Acids: Many organic acids such as sulfuric acid, hydrochloric acid , nitric acid…etc. are dangerous when they come in contact with tissues. B) Strong bases: Many bases such as NaOH, KOH, NH4OH… etc. are highly caustic and may cause severe damages to the body c) poisons: such as cyanides, various alcohols such as methyl alcohol, mercurials Precautions when handling strong acids 1- Never hold the container from the stopper. Hold it by both hands. 2- When pouring acid or base from a bottle into another container, pour very slowly to prevent splashing. 3- When you want to dilute, always add acid to water and not the opposite. since a large amount of heat will be released if large amount is added fast to water. If heat develops, either wait for a few minutes before you add more acid or cool the container. 4-If you are using a pipette, use suction pumps. Hold the pipette against the wall of the container that has water in it. 5- After using the bottles, return them back safely to their specific place.  Precautions when handling strong bases 1-Don’t store strong bases in glass-stoppered bottles. 2-When opening a bottle that contains ammonia, be careful not to hold your face above the opening of the bottle, or better open it in a fume-hood. 3- When you want to dilute NAOH or KOH , always add it to water. If heat develops, either wait for a few minutes before you add more base or cool the container. First aid Burns –Hold the area under cool (not cold) running water for about 10 minutes then apply a moisturizing lotion, to keep the area from drying out. Acid on Clothes –wash with H2O. Alkali on Clothes –wash with H2O. If they penetrate the clothing, promptly remove the clothing, and flush the skin with water. Get medical attention immediately Acid in Eye–Wash with plenty of water Alkali in Eye – Wash with plenty of water C : Poisons  Precautions when handling with posions 1-Whenever possible, place the toxic solvents in the hood. 2-Never use a mouth pipette for transferring toxic solvents. An automatic pipette or a pipette equipped with a rubber bulb should be employed. 3- Make sure that all of the containers are properly labeled. 3- Fire and explosion  3- Fire and explosion causes  Organic chemicals such as ethers, alcohols, acetone…etc. are easily evaporated at room temperature.  Vapors of such chemicals are very inflammable. recautions to minimize accident A) Inflammable solvents must be stored in a cool room separately. Such storeroom must be equipped with ventilating devices and should be ventilated every now &then. B) The inflammable solvents should be taken to the lab as needed, and in the smallest amounts required for experiments C) Before opening a bottle containing an inflammable solvent, make sure there is no flame around. D) Never heat inflammable solvents in an open flame. E) If a fire takes place, don’t become confused. Keep calm and ask immediately your lab instructor for help!!!!  First aid Extinguisher ready. Clothing on Fire