The Safety of work with the laboratory fume hoods

1. The Safety of work with the laboratory fume hoods  General purpose: prevent exposure to toxic, irritating, or noxious chemical vapors and gases. A face velocity of 100 feet per minute (fpm) provides efficient vapor capture while reducing hood turbulence. • Baffles -- keep the airflow uniform across the hoodopening, thus eliminating deadspots and optimizingcapture efficiency. • Sash --Airflow across the hood can be adjusted bysash height to the point where capture ofcontaminants is maximized. • Airfoil -- Preventing the creation of turbulent eddiesthat can carry vapors out of the hood. The spacebelow the bottom airfoil provides source of room airfor the hood to exhaust when the sash is fullyclosed. • Exhaust plenum-- An important engineering feature, the exhaust plenum helps todistribute airflow evenly across the hoodface. • Face-- The imaginary plane running betweenthe bottom of the sash to the work surface.Hood face velocity is measured across thisplane. References University of Washington; http://www.ehs.washington.edu/fsofumehoods/fume.shtm Princeton University; http://web.princeton.edu/sites/ehs/labsafetymanual/sec6b.htm Waterloo University; http://www.safetyoffice.uwaterloo.ca/hse/fume_hoods/fume_hoods.htm Colgate University; http://www.colgate.edu/offices/administrative/financeandadministration/environmentalhealthandsafetyoffice /chemicalhygienelaboratorysafety/chemicalfumehoods

2. Safe Hood Operating Procedure • Work with the hood sash partially • or completely closed.  Move work at least six inches inside the face of the fume hood. This minimizes the effect of cross-drafts and eddies created by the hood operator or by occupants walking by the hood. Also, keeping windows and doors closed will control cross-drafts. Best Bad Good

3. Safe Hood Operating Procedure • Avoid overcrowding the fume hood work areas. • Chemicals and equipment not in use should be removed from • the hood to a proper storage cabinet. Large bulky equipment • used in the hood will cause eddies that can be reduced by • making sure there is a 1-2 inch air space on all sides • including the bottom. Avoid using equipment that blocks the • hood sash from closing.

4. Safe Hood Operating Procedure Constant volume hood – the volume of air exhausted is constant, regardless of sash height. Proper positioning of the sash is vital to maintaining the optimum face velocity (100 or 125 fpm). Too high: lowers face velocity, allowing contaminants to escape from the hood Too low: results in very high face velocity, excessive turbulence and loss of containment • Confirm that the hood is operational: switch ‘on’, airflow gauge or ‘flow check ribbon’ hood test data and optimum sash height - yellow label affixed to the hood face • Maintain operations at least 6" inside the hood face • Lower sash to optimum height: maximized airflow without turbulence (17” in accordance to the rules in Colgate University) • Keep head out of hood and Keep hands out as much as possible • Keep hood storage to an absolute minimum (Do not use your fume hood as a storage area) • Minimize foot traffic around the chemical hood • Use extreme caution with ignition • Connect all electrical devices outside of the hood to avoid sparks which may ignite a flammable or explosive chemical • Replace hood components prior to use • When fume hood is not in use, keep sash closed and ensure that all materials are in sealed containers • Prepare a plan of action in case of an emergency, especially when using extremely hazardous chemicals or acids, and a flammable or explosive chemical

5. SAFETY EQUIPMENT • In case of an emergency, you should know the location and proper use of all the safety equipment provided in the laboratory. Always immediately inform the staff of any accident. the science lab safety equipment, including: Safety Shower Eye Wash Fire Blankets Fire Extinguishers Fire Exits Telephone First Aid Kit Hand-washing sink Master gas shut-off Master electricity shut-off Biohazardous waste container Sharps containers Broken glass containers Routine garbage containers Chemical disposal containers

6. Laboratory fires A study of one hundred significant laboratory fires by the National Fire Protection Association provides some interesting facts: 71% of the fires originated in the laboratories; 56% of the laboratory fires originated between 6 PM and 6 AM; 67% of the fires were caused by: electrical equipment (wire and appliances) 21% misuse of flammable liquids 20% explosions 13% gas 7% spontaneous ignition 6%

7. Which kind of extinguisher should I use? The National Fire Protection Association classifies fires into five general categories (U.S.): * Class A fires are ordinary materials like burning paper, lumber, cardboard, plastics etc. * Class B fires involve flammable or combustible liquids such as gasoline, kerosene, and common organic solvents used in the laboratory. * Class C fires involve energized electrical equipment, such as appliances, switches, panel boxes, power tools, hot plates and stirrers.Water can be a dangerous extinguishing medium for class C fires because of the risk of electrical shock unless a specialized water mist extinguisher is used. (DO NOT USE WATER) * Class D fires involve combustible metals, such as magnesium, titanium, potassium and sodium as well as pyrophoric organometallic reagents such as alkyllithiums, Grignards and diethylzinc. These materials burn at high temperatures and will react violently with water, air, and/or other chemicals. Handle with care!! (DO NOT USE WATER) (*Class K fires are kitchen fires)

8. Which kind of extinguisher should I use?

9. Which kind of extinguisher should I use? http://safety.eas.ualberta.ca/node/46

10. Summary of Fire extinguishers http://delloyd.50megs.com/hazard/fire.html

11. Summary of Fire extinguishers *Carbon dioxide fire extinguishers are suitable for many of the potential fire hazards in the general chemistry laboratories. http://delloyd.50megs.com/hazard/fire.html

12. How to use a Fire extinguisher • In the event of a fire, evacuate the area, close all doors, call for help, • and sound local alarms.  If you attempt to extinguish it, keep your back to an exit from the laboratory, do not allow yourself to become trapped or cornered in the lab. (2) Pull out locking key. (3) Squeeze handles. (1) Aim nozzle at base of fire.

13. How to use a Fire blanket In case of a clothing fire, a fire blanket should be used. Remove the fire blanket from its container using the straps. Wrap it around the person to completely cover the person and smother the fire.

14. Clarkson University 268-6400 Emergency Number (after working hours) 268-6439 Campus Safety 268-6666 Fire Dept 9-265-3311 Hospital 9-265-3300/3304/5720 Police 9-265-2121/2122 Rescue Squad 911 (Numbers are located near the each lab exit door) How to respond to an Emergency