Use these safety moments as you see fit.

1. Safety Moment Collectionof the Joint Safety Team at the University of Minnesota, Department of Chemistry and Department of Chemical Engineering and Material Science.

2. Use these safety moments as you see fit. Feel free to adapt a safety moment to meet the specific needs and time constraints of an audience or occasion; this may mean using only a portion of the prepared slides for a topic or including additional resources for an in-depth discussion.

3. Have a safety moment?Contribute it to this collection. Send safety moments to jst@umn.edu with Safety Moment <topic> in the subject line.  Please put content in the provided template and cite reliable, credited sources.    Thank you!

4. Pharmaceutical Waste

5. Evaluating Pharmaceutical Wastes Reference: Minnesota Pollution Control Agency, 2012.

6. Chemicals and their Hazards

7. Liquid Nitrogen

8. Liquid Nitrogen • Bp: -320 ˚F (-196 ˚C, 77 K) • Expansion ratio: 1 : 694 • Burns – similar to frostbite or thermal buns • Explosions (Texas A&M, 2006; $~500,000) • Relief valvewas sealed shut • Asphyxiation(8 deaths/yr in US) • Oxygen deficiency from not being able to breathe normally • Liquid N2ingestion (18thbirthday celebration, England, 2012) • Emergency surgery to remove stomach after drinking a cocktail containing liquid N2

9. Liquid Nitrogen • Liquid N2 in the lab • Can solidify with a vacuum pump (mp 60 K) • Can condense oxygen (bp 90 K) • Liquid O2 can cause explosions • Don’t leave liquid nitrogen traps open to atmosphere! • If liquid O2 formation is suspected, alert other sto the danger and evacuate the area. • Allow the vented system to warm to room temperature • Can condense argon • Use nitrogen gas instead Liquid oxygen is pale blue

10. Controls • Always wear appropriate PPE (cryo gloves, lab coat, and goggles) and never allow any unprotected part of the body to come into contact with LN2 or any uninsulated vessels or pipes. • Do not overfill vacuum flasks and never store LN2 in a sealed container at a temperature above the BP of LN2. • Always inspect and maintain vacuum flasks. If they are cracked, they may fail explosively. • Eliminate sources of ignition around the LN2. The risk of O2condensation is also reduced when working with smaller quantities of LN2. • If pale blue liquid O2 is seen, remove LN2 traps (if any), flammables, and any ignition sources and let O2 boil off slowly.

11. References • Material Safety Data Sheet: Nitrogen, Refrigerated liquid. <http://www.liquidnitrogenservices.com.au/safety/ln2_msds_e1.pdf> • Asphyxiation with liquid nitrogen – hazard alert, Monash University. <http://www.monash.edu.au/ohs/topics/hazard-alerts/liquid-nitrogen-asphyxiation.html> • Standard operating procedure (SOP) for handling cryogenic (liquid nitrogen). <https://eee.uci.edu/programs/chemstockroom/SOP/Liquid%20Nitrogen%20SOP.pdf>

12. Liquid Nitrogen Transport

13. Liquid Nitrogen Presents Major Safety Concerns • Extreme temperature (-196°C) • Rapid evaporation and suffocation (1 L liquid  25 cubic ft) Ted Pella Inc. “Safe Handling of Liquid Nitrogen.” 2013 http://www.tedpella.com/cryo-supplies_html/HandlingLiquidNitrogen.htm

14. Transport – Plan for the Worst

15. Transporting Chemicals for Outreach

16. Transporting Chemicals for Outreach • Using chemicals for outreach activities carries the additional hazard of chemical transport in civilian vehicles • Potential dangers: • Asphyxiation from gases • Chemical spills • Chemical reactions “Transporting chemicals for lecture demonstrations & similar purposes.” Royal Society of Chemistry. 2008

17. Simple Rules • When possible, avoid transport • Transport small amounts • Maintain inventory of transported chemicals • Ensure adequate labeling, including hazard information • Avoid spills • Tight packing with soft material (cloth, bubble wrap, etc.) • Closed containers • Secondary containment (boxes, buckets) • Avoid reactions • Store incompatible chemicals in separate containers “Transporting chemicals for lecture demonstrations & similar purposes.” Royal Society of Chemistry. 2008

18. Special Cases • Liquid Nitrogen • Only use approved, vented dewars • Store in separate space from driver/passengers (i.e. car trunk) to avoid asphyxiation hazards • Pack dewar such that it cannot fall over or spill • Gas Cylinders • When possible, use small and non-refillable containers “Transporting chemicals for lecture demonstrations & similar purposes.” Royal Society of Chemistry. 2008 http://www.phy.cam.ac.uk/hands/hazards/gases.php

19. How to Handle “The Heat” Fire hazards and autoignition temperatures

20. Temperatures • Furnaces, ovens, hot plate, oil baths550-1000 oC, 100-200 oC, up to 100 oC • Saturated steam (1 bar): 100 oC • Minnesota summer: 23 oC, 73 oF(Jul. avg in TC) • Ice/water: 0 oC Wikipedia: Climate of Minnesota

21. Flames (adiabatic flame T, const p) Wikipedia: Adiabatic flame temperature Physics Stack Exchange

22. Autoignition temperatures • Diethyl ether (160 oC) • Diesel (210 oC) • Paper (218-246 oC; 451 oF) • Gasoline (246-280 oC) • Ethanol (363 oC) • Butane (405 oC) All similar to heating eq. in the lab, lower than flames. Wikipedia: Autoignition temperature

23. Hazards • Fireflammables in contact with hot objects • Thermal burnsskin in contact with hot objects

24. Open reactive volatiles in the hood Example from a Learning Experience Report (LER)

25. Reactive Volatiles During working hours, bottle of acetaldehyde was opened outside of the fume hood. A plume of vapor was released into the lab and the lab was evacuated. No injury resulted. The participate knew what do in the incident (8/10), but did not have much prior experience with the activity/technique (2/ 5). To prevent incident: • Open the bottle inside of a fume hood.

26. Acetaldehyde - SDS Flammable Health Hazard Acute toxicity, Inhalation Boiling point = 21°C Acetaldehyde. MSDS. Sigma-Aldrich. http://www.sigmaaldrich.com

27. Peroxide Forming Chemicals Diethyl ether Isopropyl alcohol THF

28. Ether Safetyoverview • Ether can form peroxides when exposed to air • Peroxides are shock-sensitive explosion hazards To minimize risks: • Purchase what will be used within the month • Purchase Ethyl Ether that contains peroxide inhibitors such as BHT or ethanol • Store away from heat and light • Test for peroxide formation monthly after expiration Less than 80 ppm peroxides Solution is okay to use Call the Chemical Waste Program for packaging and removal 80 ppm to 400 ppm Call the Chemical Waste Program, who will contact the Bomb Squad Greater than 400 ppm

29. Peroxide Forming Chemicals • Many solvents can form shock-sensitive peroxides over time • Diethyl ether • Isopropyl alcohol • THF • Friction, shock, or concentration can cause an explosion • Graduate student at UC-Irvine sustained cuts from exploding glassware while concentrating diethyl ether Explosion was partially contained in water bath, residue visible on rotovap glassware “Lesson Learned” from University of California Irvine 2006 <http://www.ehs.uci.edu/salerts/Lesson%20Learned_Peroxide.pdf>

30. Peroxide Forming Chemicals Ordering and Storage • Only order the amount needed for one month • Label when first received and when first opened • Store away from light, ignition sources, and oxidizers • Test for peroxides every month after listed expiration date has passed Department of Environmental Health and Safety Hazardous Chemical Waste Management Guidebook, Section 5 “Waste Requiring Special Processing” <http://www.dehs.umn.edu/hazwaste_chemwaste_umn_cwmgbk_sec5.htm#pfc>

31. Peroxide Forming Chemicals Testing for Peroxides • Call DEHS if • Crystals are present in or around the container • Container has a metal screw cap • Container has been stored for more than two years • If the above are not present, test with peroxide test strips • Less than 80 ppm is okay • Greater than 80 ppm, call DEHS for disposal http://www.conncoll.edu/offices/ehs/peroxide-forming-chemicals.htm http://www.rhr-inc.com/bigcrys.htm

32. Base BathCauses Chemical Burns Example from a Learning Experience Report (LER)

33. Base Bath During working hours, a researcher removed glassware from the base bath wearing wrist length nitrile gloves. The basic solution went over the gloves and was trapped against the skin causing severe chemical burns on the wrist. The participate knew what do in the incident (10/10), and had prior experience with the activity/technique (5/ 5). To prevent incident: • Wear gloves that extend up past the wrist. • Use gloves made of a compatible material (like neoprene).

34. Aqua Regia

35. Aqua Regia Materials and Methods: Aqua Regia is a mixture of concentrated nitric acid and hydrochloric acid used clean glassware of trace contaminants. If a milder reagent can accomplish the same task, aqua regia is not recommended. Prepare only the smallest amount needed. Mix 1 part HNO3 with 3 parts HCl. • In fume hood, add the HNO3 to a glass container. Then add HCl. Gently swirl to mix. Pour acids from smaller containers, not from stock bottles. Aqua regia should NEVER be taken out of the hood. Slowly pour or pipet the aqua regia solution into the glassware to be cleaned. Gently swirl or rinse with a flow from a pipet. Allow glassware to soak for several minutes if solids do not readily dissolve. Hurley, Katie. Haynes Lab SOP, Aqua Regia Use and Neutralization

36. Aqua Regia Waste Disposal Methods Dilution and Neutralization: • Use secondary containment for Aqua Regia waste container that is free from all organic chemicals/solvents. • Dilute used Aqua Regia with water by a factor of 7.5. In a beaker, SLOWLY add the Aqua Regia to the full volume of water. Avoid overheating, and stir solution on a stir-plate. • SLOWLY neutralize by adding sodium bicarbonate solution dropwise. Periodically check the pH with pH paper (aiming for pH 6-9). • Allow solution to cool to room temperature before moving to the waste container, capping the container, or transferring the solution. Disposal: After the solution has cooled to room temperature, all liquid may be added to the waste container labeled “Neutralized Aqua Regia Waste.” Hurley, Katie. Haynes Lab SOP, Aqua Regia Use and Neutralization

37. Aqua Regia Required PPE: Goggles, lab coat, chemical-resistant gloves (18 mm neoprene, Silver Shield, or any other glove rated to protect against hydrochloric AND nitric acid). Face shield and acid-resistant apron are recommended if working with a larger volume (>200ml). Hazards: • Strong oxidant – Keep away from organics • Corrosive – Wear goggles, thick gloves, lab coat • Acidic – Strong reaction with bases • Off-gassing of toxic fumes • Keep in the hood at all times and never stopper or store. Hazard Response: • Spill of <200 mL spent solution in hood: soak up with HazMat pads • Spill outside hood or > 200 mL : evacuate and call DEHS Hurley, Katie. Haynes Lab SOP, Aqua Regia Use and Neutralization

38. Acid Piranha

39. Acid Piranha Solution Traditionally a 3:1 solution of sulfuric acid to 30% hydrogen peroxide (v:v) • Highly exothermic • Acid piranha will melt plastics, and the oxidative reaction is accelerated by water, acid, and base • Do not generate excess piranha or cap your solutions! • Only use in a well ventilated hood • Slowly add peroxide to acid directly in the glassware to avoid uncontrolled reactions Glassware must be cleaned and dried prior to use! Piranha MUST be neutralized or manifested separately due to reactivity with organic molecules. http://blink.ucsd.edu/safety/research-lab/chemical/specific/piranha.html http://www.cmu.edu/ehs/fact-sheets/piranha-solution-handling.pdf

40. Don’t mix bleach and ammonia

41. Hazards of Mixing Bleach and Ammonia When ammonia and bleach are mixed, this chemical reaction occurs: NaOCl (bleach) + NH3 NaOH + NH2Cl • NH2Cl (chloramine fumes) are hazardous when concentrated • Intermediate products include HCl and chlorine gas • Biggest hazard is inhalation • If mixed, leave the area and ensure good • ventilation before returning Helmenstine, A.M. “Mixing Bleach and Ammonia: Chemical Reactions from Mixing Bleach and Ammonia” About.com Chemistry. <http://chemistry.about.com/od/toxicchemicals/a/Mixing-Bleach-And-Ammonia.htm>

42. Palladium on Carbon is a flammable solid Example from a Learning Experience Report (LER)

43. Pd/C During working hours, method vapor was ignited in the presence of a Pd/C catalyst used during a hydrogenation. No injury resulted. The participate knew what do in the incident (10/10), and had prior experience with the activity/technique (5/ 5). To prevent incident: See Pd/C Safety moment for more detail • Add catalyst to reaction vessel under an inert atmosphere. • Then add solvent slowly under inert gas. • Dispose of Pd/C in special waste bottle with water present.

44. Pd/C Explosion At another university, a fire was started by a bottle of Pd/C disposed of in a plastic waste container in the lab. Luckily, the fire did not spread beyond the trash receptacle and it resulted in no injuries. Improper handling of waste lead to disaster. April 2012 Newsletter, U W-Madison, Office of Chemical Safety. Http://www.ehs.wisc.edu/chem-issue1Volume2-improperhandlingchems.htm

45. Pd/C and Hydrogenation

46. Pd/ C Hydrogenations • Danger comes from the active catalysts • Absorb hydrogen gas • Can spark spontaneously and may ignite on exposure to air • Readily causes ignition of flammable solvents in the presence of air. • Use in presence of H2 gas, sometimes at high pressure and temp. • In the event of fire, contain it with water • Types of Catalysts • Degussa – safest • Wet – safer. Higher % of water • Dry Do not operate near flammable materials Perry, David. Hazards in Hydrogenation. http://chemicalspace.wordpress.com/2010/07/27/hazards-in-hydrogenation/

47. Pd/ C Hydrogenations • Correctly done, these reactions can be routinely run safely • Weigh and add catalyst first • Flush vessel with nitrogen. Handle Pd/C under inert atmosphere. • Add solvent. (Degas solvent with large scale > 100 mL) Use ethanol, not methanol (very flammable, invisible flame) • Flush reaction vessel with N2 , run reaction, repeat flush with N2 • Remove Pd/C through filtration (celite on glass frit), and cover with wet sand. Filter cake should never be allowed to dry, and the moist material should be added to a large quantity of water and disposed of properly. • Dispose of waste in dedicated container that contains water. • Know how to use the equipment • Don’t over-pressurize • Don’t use damaged equipment or glassware. Prudent Practices in the Laboratory: Handling and Disposal of Chemicals Laboratory Chemical Safety Summary: Palladium on Carbon

48. Pd/C According to Prudent Practices in the Laboratory, palladium on carbon catalysts containing adsorbed hydrogen are pyrophoric, particularly when dry and may ignite on exposure to air

49. Mercury Spill From a broken thermometer

50. Broken Mercury Thermometer • If Hg droplets or pools are observed: • Isolate spill area and do not walk through the area • Call DEHS: 612-626-6002/ 9-1-1 after hours • Leave any shoes or clothing contaminated with Hg droplets aside for cleaning • A specialized staff will come to monitor, decontaminate and cleanup • If Hg spills on a heated surface (hot plates, ovens) • Turn off equipment and evacuate the lab. • Call DEHS: 612-626-6002/ 9-1-1 after hours • If a Hg thermometer bulb is cracked: • Seal in plastic bag and dab immediate area with a wet towel and add to plastic bag. • Manifest as Hg-containing waste • Accidental releases (drain, soil, trash) • Report to DEHS http://www.dehs.umn.edu/hazwaste_mercthemom.htm