The Campaign for McMaster University Information Guide to Fume Hoods Facility Services (ext ) By: Jassica Johnpillai and Kaylea Cassano June 2013

A fume hood is designed to protect researchers from inhaling hazardous airborne chemicals and materials that may be used in a lab Fume hoods contain and redirect chemical contaminants, and prevent their escape into the laboratory What is a Fume Hood?

Two primary goals: Protect the user from inhaling toxic fumes Protect the product or experiment Primary Goals

Secondary functions of these devices may include explosion protection, spill containment, and other safety functions necessary to the work being done within the device Secondary Goals

There are three different designs of fume hoods – The first has its sash open vertically – The second has its sash open horizontally – The third opens both horizontally and vertically Styles of Fume Hoods

The fume hood is designed to minimize the fluctuation in face velocity as a sash is lowered or raise Air enters the fume hood through the openings along the top and underneath the airfoil How it Works

Bypass Hood Sash Airfoil Components of a Fume Hoods

When the sash is in the fully closed position fumes can still be captured The baffle directs the air to follow specific flow patterns within the fume hood and also generates a uniform velocity of air How it Works Continued

Air is drawn in from the front (open) side of the cabinet, and either expelled outside the building or made safe through filtration and fed back into the room How it Works Continued

Be aware of any differences in visual or audible cues that can be seen on the fume hood alarm Do not override these alarms Keep the slots of the baffle free of obstruction Never place your head inside the fume hood Do not use the fume hood as a storage area for equipment-this can cause airflow blockage and allow fumes to escape Substitute toxic chemicals with less hazardous materials whenever possible Safety

First, turn on the light in the fume hood so that it is easier to see what is being done within the fume hood – Light switch usually located on the outside front face of the fume hood When using a Fume Hood

Secondly, check the fume hoods annual inspection sticker Hoods are tested annually When using a Fume Hood

Thirdly, check the airflow digital monitor – Some fume hoods do not have a digital monitor If the fume hood is in alarm do not use the fume hood and call ext

When using a Fume Hood Finally, when finished turn off the light and close the sash fully to conserve energy

Face Velocity is the speed at which air moves into the fume hood across the sash Face Velocity is at its safest when it is between 80 and 120 ft/min The Face Velocity of a fume hood is tested annually What is Face Velocity?

1.Smoke Test 2.Face Velocity measurements 3.Light and Sash operation 4.Valve operation 5.Calibrating monitors 6.Test emergency purge systems 7.Examine the structure and the housekeeping of the fume hood How are Fume Hoods tested?

Requires a smoke pencil to visually show the ability of the fume hood to remove airborne materials The Smoke Pencil is placed at different positions to show consistency of flow Smoke Test

Produces measurements of hood velocity in three or four readings depending on the size of the fume hood Readings taken with a calibrated micromanometer Results are shown on the hoods certification page on the Facility Services website Face Velocity Test

Fume hood testers check to make sure that all lights in the hood are working to maximize safety The sash is checked to be in working order – The sash does not stick when moved – The sash is not loose in its position Light and Sash Inspection

Valve Operation Test the valve systems within labs All valve types include an immediate response mechanical assembly to maintain airflow when hoods are in use

Calibrate Monitors/Emergency Purge Test fume hood monitor for calibration and calibrate when required Test the Emergency Purge systems to ensure they are in working condition

Structure and Housekeeping Finally, testers look at the fume hood itself to determine its working condition – This includes examining the various components of the fume hood For example: screws, lights, siding Housekeeping of both the lab and the fume hood is important – The lab is safer when there is less clutter – The fume hood itself has better airflow when it does not have large objects within it

Airflow can be disturbed which causes airborne contaminants to escape the hood – To minimize this occurring stand as far back from the hood as possible Safety

It is important to conserve energy consumption and to lower our carbon footprint Each fume hood has stickers indicating proper sash height, they also have stickers to remind lab users to close the sash when not in use Energy Efficiency

One fume hood’s energy is equal to that of three to five households per year Average labs at McMaster contain four fume hoods per room… That is the equal to the energy consumption of twenty houses! Closing the sash is an amazingly simple act that has a huge potential to help the environment Energy Efficiency

To learn more about McMaster’s fume hood policies please visit the Laboratory Safety Handbook: +safety+handbook&cx= %3Aakq6v26t6nm&hq=inurl%3A mcmaster.ca&cof=FORID%3A11

To reach Facility Services call (ext ) Or visit the website at: