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S a f e t y in an Organic Synthesis Lab


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S a f e t y in an Organic Synthesis Lab

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  1. Safetyin an Organic Synthesis Lab

  2. THE CHEMISTRY LABORATORYINCLUDES HAZARDS AND RISKS. This presentation assumes your knowledge of the safety rules for an introductory organic laboratory. If you did not take organic chemistry (231L/232L) here, you should review the information in the attached link: Organic Chemistry Lab Safety

  3. 1. PPE Personal Protective Equipment: What must be worn when you work in the laboratory. Eye Protection Lab Coat Long Pants Closed Toed Shoes and Socks– no exposed skin around feet Lab gloves – when required

  4. Eye Protection • Contact lenses are OK as long as glasses/goggles are worn • Prescription glasses – you must wear goggles over them • Safety goggles are provided in organic labs in UV irradiating cabinets • Eye wash stations are present in all labs

  5. Clothing and Foot Protection  • Clothing must cover all exposed skin including legs/ankles • Socks as required PPE • Stockings or leggings do not provide good coverage • Sandals, flip-flops, Crocs, open-toe and open-top (i.e. ballet flat) shoes and canvas shoes (i.e. Toms) are not appropriate. These are not going to protect your feet if you drop a piece of glass with a liquid chemical reagent in it.  

  6. Hand Protection: Chemically resistant Lab Gloves ✓  • Wear gloves of a material known to be resistant to permeation by the substances in use – nitrile is good for most of our laboratory classes. • Inspect each glove for small holes or tears before use. • When you spill on your glove or tear it, change it immediately. Throw gloves away any time you take them off.

  7. Use of Gloves Remove gloves before handling objects such as doorknobs, telephones, pens, computer keyboards, pH meter or other electronic buttons, or phones while in lab. It might be convenient to have one gloved hand and one ungloved hand to do procedures where these kinds of things are used. • Throw away gloves anytime you take them off. • You should expect to use several pairs of gloves in any given lab period. • Glove video (Review this video if necessary)

  8. Glove Recycling ContaminatedGloves with visible signs of chemical exposure or those usedwith hazardous substances should be collectedin solid wasteor Uncontaminated Gloves that have no visible signof chemical exposure or residue can be placedin the gloverecycling container. biohazardcontainers. If there’s any questions or the boxes need attention,please contact Dr. KatherineMullaugh. Email: mullaughkm@cofc.eduPhone:843.953.6587

  9. 2.Safety Equipment in the LabEyewash and Safety Shower: Know where these are in your lab.

  10. Eyewash / Safety Shower The safety shower is on the right. Pull the handle and water will start spraying from the shower head on the ceiling. There’s no drain in the floor – we only do this in emergencies, because a flood of water will have to be cleaned up. The eyewash is on the left. Pull the handle and a fountain of water will appear that you can use to bathe your eyes.

  11. 3.Chemical Fume Hoods: You must do your experiment in the hood if any of your reagents are flammable, have harmful fumes or present a splash or explosion hazard. This means pretty much at all times for organic chemists.

  12. Using the Fume Hoods properly This window/bar is called the sash. If this is not saying NORMAL, then the hood is not protecting you. Keeping the sash and sliding panels in proper position keeps this NORMAL, otherwise the alarm goes off. If the alarm goes off, you need to reposition things to the correct positions, then press the “mute” button to reset the controller. The sash should never be raised above the green “operation” level when you are working in the hood.

  13. In use, side-to-side panel used as shield Closed, not in use ✓ ✓- In use, sash (window) raised to less than 18 inches Don’t open side shields to make one big window. × ✓

  14. BEFORE USING THE HOOD: MAKE SURE IT IS NEAT & CLEAN & UNCLUTTERED. • When using a laboratory hood, Check that the airflow is in the normal range on the digital display • Turn on the hood light • Set the equipment and chemicals back at least 6 inches. • Never lean in and/or put your head in the hood when you are working. This is worse than doing the experiment with no hood at all. http://web.princeton.edu/sites/ehs/labsafetymanual/SOC.htm ehs.unc.edu/training/self_study/fume_hood/docs/fume_hood.ppt‎

  15. Know the risks of the chemical reagents you are working with andthe procedures you are going follow.Unlike the introductory organic laboratory the chemicals used in this course will be dangerous, at times with unknown health risks.Unlike the introductory organic laboratory, the procedures will be dangerous, at times very dangerous.

  16. Labels are important Even if it seems obvious. In the chemistry lab, nothing is ever obvious.

  17. TAG IT!!! On all reaction set ups On all NMR tubes On all GC-MS vials On all temporary storage flasks, beakers, etc. On all Rotovaps when in use

  18. NFPA Diamond

  19. NFPA Label For Intermediate or Long Term Use • On products, once characterized. • On solvent solutions prepared for chromatographic separations. • On acid or base solutions. • On reagents transferred into secondary containers. • On anything that will be in the lab that does not have a primary label from the manufacturer or a string tag label you put on it.

  20. Where to Find NFPA and Safety Information? From MSDS sheets • on OAKS • on manufacturer website • hard copies in the lab • ask instructor if you cannot locate the MSDS you need

  21. Incompatible materials • Certain chemicals should not be stored and cannot be safely mixed with certain other chemicals due to severe reaction exotherm or uncontrolled production of a toxic product. Every lab has a legible matrix that lists the general classes of materials that should not be mixed together:

  22. Regulatory agencies and standards • Over the last 40 years the US and state governments and various international bodies have developed regulations and standards that try to improve safety and industrial hygiene standards including the following: • EPA: Environmental Protection Agency, who have the primary responsibility to ensure chemicals are used and disposed of in an environmentally sensitive manner • TOSCA: the Toxic Substances Control Act of 1976 regulates which chemicals may be produced or imported in the US • OSHA: Occupational Safety and Health Administration is the US agency that assures safe and healthful working conditions by setting and enforcing standards • NIOSH: National Institute for Occupational Safety and Health is responsible for researching the prevention of work-related injury and illness, and providing guidance to OSHA • RCRA: the resource conservation and recovery act of 1976 that sets the standards for chemical waste disposal in this country and oversees the “superfund law” CERCLA • California Proposition 65: The state of California passed a very rigorous law to protect drinking and ground water from toxic chemicals. It is increasingly the standard for companies when evaluating chemical safety All of these regulations have been developed to make the use and handling of chemical safer, and their impact on lab safety has been profound.

  23. Acute and chronic toxicology • Acute toxin: rapid absorption of the substance and the exposure is sudden and severe. Normally, a single large exposure is involved. • Examples are carbon monoxide, hydrofluoric acid, hydrogen cyanide and nicotine • Chronic toxin: prolonged or repeated exposures of a duration measured in days, months or years. Symptoms may not be immediately apparent. • Examples of chemicals of high chronic toxicity include dimethylmercury, nickel carbonyl, benzo-a-pyrene, N-nitrosodiethylamine, and other human carcinogens or substances with high carcinogenic potency in animals

  24. Carcinogens, mutagens and teratogens • One of the most significant chronic risks associated with chemicals is their potential to cause cell mutation and proliferation. • Carcinogen: chemicals that can increase the incidence of cancer in the body • Mutagen: chemicals that cause mutations in DNA that lead to hereditary genetic defects in a fetus • There are two other general classifications that you should be aware of: • Teratogen: chemicals that induce non-hereditary malformations of a fetus • Sensitizer: chemicals that no reaction in a person during initial exposures, but further exposures will cause an allergic response to the chemical

  25. Routes of Entry and Allowable Exposure Limits • There are four main routes by which hazardous chemicals enter the body: • Inhalation: Absorption through the respiratory tract. Most important in terms of severity. • Skin absorption. • Ingestion: Absorption through the digestive tract. Can occur through eating or smoking with contaminated hands or in contaminated work areas. • Injection. Can occur by accidental needle stick or puncture of skin with a sharp object. • Most exposure standards, Threshold Limit Values (TLVs) and Permissible Exposure Limits(PELs), are based on the inhalation route of exposure. expressed in terms of either parts per million (ppm) or milligrams per cubic meter (mg/m3) concentration in air. • Other measures of chemical exposure: • Lethal dose or concentration for 50% of the exposed population (LD50 or LC50) expressed in mg contaminant per kg of body weight • Short term exposure limit (STEL or TLV-STEL) is the amount of a substance you can be exposed to for 15 minutes four times a day

  26. 5.Fire Safety

  27. Fire Alarms & Extinguishers Where are the ones closest to you?

  28. Types of Fire Extinguishers This is a special fire extinguisher for combustible metal fires. It is a type D fire extinguisher. You won’t need to use this unless you work in a research lab with combustible metals. Most of our fire extinguishers are ABC. It contains a dry powder to put out the kinds of fires we might encounter in the chemistry labs where we have class.

  29. Student Reaction in a Fire Although we want you to be informed on the operation of a fire extinguisher, we do not expect you to use it. If a fire is ignited in your area, the proper STUDENT response is to: • Notify everyone in the room • If possible shutdown any reaction in progress by removing heat/energy source and/or pulling plug on power cord • Proceed to the nearest exit and pull the nearest fire alarm • Evacuate the building • Assemble in front of the library for a positive headcount

  30. Flammables, combustibles, and potentially explosive materials • There are different ways of designating that a chemical is a fire risk: • Flashpoint - minimum temperature at which a liquid gives off a vapor in sufficient concentration to ignite in the presence of an ignition source • Combustible liquid - Any liquid having a flashpoint at or above 37.8oC (100 F) but below 93.3oC (100 F) • Flammable liquid - any liquid having a flashpoint below 37.8oC • Autoignition temperature - the lowest temperature at which it will spontaneously ignite in a normal atmosphere without an external source of ignition, such as a flame or spark • Explosive - A chemical that causes a sudden, almost instantaneous release of pressure, gas, and heat temperature.

  31. Bad things can happen!! • You need to be aware of what you are doing, and the risks of what you are doing. • You also need to be aware of what others in the same lab room are doing, and the risks of what they are doing.

  32. Working with flames • Flames are never allowed when flammable gases or liquids are in use near by. • Always alert others before lighting a flame. • Never leave a flame unattended under any circumstances. • Do NOT heat reactions with flames!!! • Turn off the natural gas at the valve when you are finished with your work. • In the synthesis lab, Bunsen burners are used to either (1) to pull TLC spotting tubes; rarely (2) to dry glassware or very rarely (3) to conduct flame or combustion tests. • Drying glassware with a Bunsen burner can only be done if ALL flammable materials are taken out of the hood first. • Placing glassware in the drying oven overnight is the preferred method to dry glassware, so plan ahead!! Closed valve is Perpendicular to hose

  33. Guides On Procedures • For some processes or procedures there will be Departmentally approved (and EHS approved) Standard Operating Procedures (SOP) that must be studied and followed. • For some processes or procedures there will be technical notes or experimental descriptions (these may or may not be formally sanctioned by the Department or EHS) that must be studied and followed. • In all cases, if the Department or EHS mandate it, a formal SOP takes precedence over an instructor’s technical notes or experimental description. • SOP’s are generated to address known hazards of an extreme nature (like handling tert-butyl lithium) or if there is a perceived need (by instructor, Department, or EHS) for an SOP. • If you feel that an SOP is needed, but one is not in place, please let BOTH your instructor (or lab supervisor) and Department chair know about your concern. • Generating an SOP is not always fast, but in some cases, it may be necessary. www.cchem.berkeley.edu/rsgrp/SOPs/Organolithium.doc www.baylor.edu/content/services/document.php/203287.doc

  34. Working with Syringes • There are many types of syringes • Plastic or glass • Leur lock or non-Leur Lock

  35. Caution if using non-Leur-LockCaution if using Plastic • The needle and syringe can be easily separated if not “locked” in place with the Leur-Lock system. • Use of non-Leur-Lock connections requires TWO hands, one on the connection, one on the plunger/syringe • Plastic syringes dissolve in many organic solvents • Plastic syringes and non-Leur Lock syringes should NEVER be used to transfer pyrophoric materials

  36. UCLA Lab Fire: December 29, 2008 Sheri Sangji was using this plastic syringe to transfer tert-butyllithium. This was not the correct procedure, because this compound is well-known to ignite if it is comes in contact with air. The syringe plunger dropped out of the syringe and the reagent ignited. Sheri died January 16, 2009 of severe burns. She was wearing nitrile gloves but no lab coat. The students assisting her did not remember to put her under the safety shower.

  37. Lessons from UCLA accident Lessons: Know the proper procedures for transferring dangerous reagents. Wear your lab coat at all times in the lab. Know where safety shower and other emergency equipment is – you may need to be the one who needs to be ready to act when your lab mate is unable to help himself/herself.

  38. Do not stab yourself!!! • Use only ONE hand if recapping a syringe needle. • Use needles only once if they come in contact with reagents or solvents. • Put all used needles for disposal into an approved “Sharpes” container.

  39. Working with Silica Gel • Inhalation of fine silica gel particles can lead to a disabling, irreversible, horrible disease called “silicosis”. • Sand at the beach is silica gel, but its particle size is large compared to silica gel used for chromatography. • Treat silica gel used for chromatography as an extremely hazardous substance. • Don’t eat it of course, but remember it is VERY unsafe to inhale.

  40. Working with a Vacuum Line • Vacuum lines are often used to strip off trace, otherwise tightly adsorbed solvent molecules. • Vacuum lines are often used to purge (remove) and then charge (refill) the atmosphere over a reaction to remove unwanted oxygen or atmospheric moisture. • When put under a vacuum, glassware is stressed. • A star crack in the bottom of a flask subjected to a strong vacuum could cause the flask to implode. • Implosions can cause as much damage or harm as an explosion.

  41. Working with An Inert Gas line • Make sure there is a pressure relief pathway for gas to escape BEFORE turning on the gas supply. • Literally trace the flow of gas from the outlet to the atmosphere, through a bubbler, with a finger BEFORE turning on the gas supply. • Use the minimum positive pressure necessary to keep atmospheric gases from entering the system. • Do not use a gas line if the low pressure regulator exceeds 20 psi.

  42. Working with a Rotary Evaporator: Let’s go RV’ing. • Get a tare weight of final RBF before removing the solvent. • Save time by RV’ing in stages: start with large RBF work down to small RBF. • Never fill any RBF over half full before RV’ing. • Clean up after AND before each use for a single concentration. • The glassware is thick walled and expensive. • The rotovap glassware should be either coated in plastic or wrapped with electrical tape. • Make sure the solvent trap is empty after AND before using the rotovap. Put collected solvent stripped off by rotovap into waste container. • Never apply a vacuum to a heated solution. Apply the vacuum, then warm it up. • Spin it fast enough to avoid bumping, but use bump bulb all the same. • The order for turning on the rotovap (attaching RBF, applying vacuum, closing stop cock, lowering into water bath) is the opposite of the order for turning it off (raise out of water bath, open stop cock, turn off vacuum, remove RBF).

  43. Working with Compressed Air • It can really jet out: show some caution. • It can really make a lot of noise: show some consideration. • It might have grease in it: do not use on “pure” compounds. • It might not actually work: the compressor can be broken.

  44. 7.Disposal Procedures

  45. Broken Glassware • Always check your glassware and discard any with chips, breaks, or obvious flaws. • Throw away broken glassware into special glass waste containers, NOT the trash. YES NO

  46. Glove Recycling ContaminatedGloves with visible signs of chemical exposure or those usedwith hazardous substances should be collectedin solid wasteor Uncontaminated Gloves that have no visible signof chemical exposure or residue can be placedin the gloverecycling container. biohazardcontainers. If there’s any questions or the boxes need attention,please contact Dr. KatherineMullaugh. Email: mullaughkm@cofc.eduPhone:843.953.6587

  47. Waste Disposal • Waste containers are provided for chemical waste generated in laboratories • Some things can go down the sink, some can’t. Always check with your instructor. • Care must be used to avoid mixing incompatible chemicals such as • Acids with Bases • Oxidizers and Flammables • Water reactive and aqueous solutions • Cyanides and acids

  48. RECORD ALL WASTE DEPOSITS Use the waste stream list for the appropriate container: For each addition to the aqueous, organic or solid waste container you MUST record Month/Date; Your Initials, ID of waste, and amount of waste. e.g.: EtOAc with trace hexane impure sodium benzoate 2:1 CH2Cl2:hexane ~200 mL ~5 g ~55 mL

  49. Handling Waste in Organic Labs • Organic liquids like CH2Cl2 (aka methylene chloride, dichloromethane) & acetone, & TBME & liquid reagents PUT IN ORGANIC (HALOGENATED) LIQUID WASTE CONTAINER IN WASTE HOOD • Aqueous – neutral (not basic or acidic) containing trace organics PUT IN AQUEOUS WASTE CONTAINER IN WASTE HOOD • Aqueous – neutral (not basic or acidic) containing NONTOXIC salts with no trace organics CAN GO IN PUBLIC SEWAR, DOWN THE DRAIN (Use the “Would I want to swim it rule?”. Yes? Then put it down the drain. NO? Then put it in the aqueous waste container.) • Solid chemical – old products, left over starting materials, includes organic and inorganic PUT IN SOLID WASTE CONTAINER IN WASTE HOOD • Solid, non toxic waste (paper towels, notebook pages) PUT IN TRASH ONLY IF SAFE TO TOUCH WITH BARE HANDS

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