Safety in an Organic Lab

1. Safety in an Organic Lab

2. THE CHEMISTRY LABORATORYINCLUDES HAZARDS AND RISKS. This presentation summarizes some of the safety rules for an organic laboratory. If some of the material is unfamiliar, or you did not take general chemistry at the College of Charleston, you should review the information in the attached link: General 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 – 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 • 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. Result of Improper Footwear in a Laboratory Northwestern University, Evanston, IL July 2003 Your instructor will send you home to change if you do not have appropriate shoes or other required PPE.

7. 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.

8. Karen Wetterhahn(October 16, 1948 – June 8, 1997) The latex gloves she was wearing were not resistant to methyl mercury – it passed through the glove, through her skin, entered her blood system and resulted in her death weeks after the exposure. Dartmouth College

9. 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.

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

11. 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.

12. Eye Wash

13. Safety Shower

14. 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.

15. 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.

16. 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. × ✓

17. 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. • It’s a good idea to put liquid reagent containers in trays to catch all spills and drips

18. 4.Know the risks of the chemical reagents you are working with

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

20. NFPA Diamond

21. MSDS (SDS) • Provides procedures for handling or working with that substance in a safe manner • Includes physical data: melting point, boiling point, flash point, etc. • Includes safety data: incompatibilities, toxicity, health effects, reactivity, storage, disposal: protective equipment & spill-handling procedures first aid

22. How to find an MSDS • There are on-line repositories of MSDS that can be searched by the following methods: • Common Name • IUPAC (International Union of Pure and Applied Chemistry) Name • C.A.S. NUMBER – (Chemical Abstracts Service) a number assigned to all commercialized chemicals available in the US • The easiest to use is the CAS number, as it is a unique identifier that isn’t subject to spelling errors • MSDS for each experiment are posted on OAKS

23. 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:

24. Texas City Disaster of 1947 • Incompatible oxidizer and fuel source mixed • Worst industrial accident in American history • Freighter full of ammonium nitrate and fuel oil (ANFO) exploded, igniting other ships • 581 dead, entire city devastated Ship anchor thrown across city by explosion

25. Introductory toxicology • AN MSDS contains valuable information on the health dangers of the chemicals but often use concepts and acronyms that are new to students: RCRA IDLH NIOSH CAS # PEL LD50 and LC50 OSHA TLV TWA Right to Know acts STEL PROP 65 Mutagenicity vs. teratogenicity TOSCA You need to know what is what to read an MSDS

26. 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 overseesthe “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, so their impact on lab safety has been profound

27. 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

28. 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

29. 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

30. 5.Fire Safety

31. Fire Alarms – know the location of one close to your lab

32. Fire Extinguishers – we have several in the labs and in the hallways.

34. 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.

35. 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 or in the YWCA parking lot for a positive headcount

36. 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 37.8 oC (100 F) but below 93.3 oC (200 F) • Flammable liquid - any liquid having a flashpoint below 37.8 oC • 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.

37. Synthesis of explosive material • In organic lab we often do reactions to add functional groups to benzene rings. A simple reaction is shown below: • If a student overcharged the amount nitric acid and overheats the reaction the following chemical is isolated: • Another risk is the formation of Peroxides – Explosives that can be generated in lab when organic ethers are heated for a prolonged period in the presence of air. Trinitrotoluene If this is not handled carefully there are serious repercussions:

38. Working with flames • Never leave experiments unattended unless you take special precautions to avoid accidents and you notify the responsible individuals. • Flames are never allowed when flammable gases or liquids are in use. • Always alert others before lighting a flame. • Never leave a flame unattended under any circumstances. • Turn off the natural gas at the valve when you are finished with your work • In the organic lab, Bunsen burners are rarely used to either (1) to pull TLC spotting tubes; or (2) to conduct flame or combustion tests. Closed valve is Perpendicular to hose

39. 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.

40. 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.

41. 7.Disposal Procedures

42. 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

43. 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

44. University of MarylandSeptember 26, 2011 • Students were conducting an experiment with nitric acid and sulfuric acid was added into a chemical waste container, causing a violent chemical reaction sparked a small fire in and near the laboratory chemical ventilation hood. • Two female students were injured as a result • Sustained first- and second-degree chemical burns and superficial cuts.

45. 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

46. Think First, Dispose Second • Paper, without Chemical Residue • Clean Broken Glass • Chemical Waste • Paper, without Chemical Residue • Clean Broken Glass • Chemical Waste • Paper, without Chemical Residue • Clean Broken Glass • Chemical Waste

47. 8.How to be a good lab citizen

48. SEVEN must-have habits for lab-work • Be prepared before walking into the lab. • Think about the how and why before doing anything. • Begin with a clean, neat work area; make it so. • Minimize clutter; store book bags, equipment, etc. • Have instructions, pen and notebook available. • Return materials and equipment to proper places. • Make it clean and neat and orderly before leaving.

49. Keep your lab area clean. × × Don’t block the floor in front of the eyewash/shower station. Don’t leave cords dangling because someone will trip over them. × × Don’t leave things in the floor because someone will trip over it. Throw away used paper towels and used gloves, immediately.

50. Don’t put anything on your face or in your mouth while you’re in lab. • Take care not to ingest anything in the laboratory! • Food, gum, beverages, candy, and tobacco products are never allowed in the laboratory. • Don’t apply makeup, chap-stick, lotion, or anything to your face or hands during lab. Wash your hands with soap then leave the lab before touching your face or other exposed skin. ×