Fume Hood Training

Fume Hood Training

Fume Hood Training

Revised: 3/5/10 by Nicole Saint-Aubin

  1. How Chemicals Can Hurt You

-Quickly review the presentation that was given to clean room staff and cover how harmful many of the chemicals are in the clean room.

-Hydrofluoric Acid (HF)

  • Highly corrosive, readily penetrates the skin, causes deep tissue layer destruction and destruction of bone, pain may be delayed from 1 to 8 hours, therefore early treatment is very important. Use calcium gluconate gel for treatment, show where tubes are located and how to apply.
  • Literature indicates that HF exposures of as little as 2% of body area have been fatal.

-Nitric Acid

  • Corrosive. Effects may include irritation of the nose and throat, labored breathing, as well as lung (pulmonary) edema, damage to the mucous membranes and upper respiratory tract. Onset can be several hours after exposure, after initial symptoms have subsided and victim appears fully recovered. Characterized by frothy pink sputum. Fatal if untreated.

-Resist Remover RR2, RR4 Dimethyl sulfoxide (DMSO)

  • Used as a carrier for experimental drugs. Penetrates skin, latex. Will “carry” whatever it contacts through intact skin into the bloodstream.


  • Most common: 3:1 sulfuric acid (H2SO4) : hydrogen peroxide (H2O2). Also used is the base piranha: 3:1 ammonium hydroxide (NH4OH) with hydrogen peroxide (H2O2). Both are equally dangerous when hot. Acid piranha is self-starting whereas base piranha must be heated to 60 degrees to begin reaction. Always add the peroxide to the acid. The H2O2 is added immediately before the etching process because it immediately produces an exothermic reaction with gas (pressure) release. If the H2O2 concentration is at 50% or greater, an explosion could occur.
  • Storing already mixed piranha is not allowed. Piranha in a closed container will likely explode, therefore should NEVER be stored (especially in a glass container). Used piranha should be left in an open container to cool (several hours) before disposal, or poured down the drain while the city water is running.
  1. Personal Protective Equipment (PPE)

-All PPE should be put on over the standard clean room garments.


  • There are three glove types:
  • The clear lightweight gloves that are donned in the gowning room. Those must be worn at all times when you are in the clean room.
  • The clear lightweight clean room gloves that are donned in the gowning room are made of Nitrile and are only 5 mil thick at the finger tip. They have only mediocre chemical resistance and are mainly intended to be used for applications requiring low-particulates.
  • The orange acid gloves that are found in the clean room stock room. Those are required if you are working with acids or bases. These gloves are disposable, single use gloves. Please throw them away when you are finished.
  • The green Nitrile gloves that are found in the clean room stock room. Those are required only if you are working with solvents (if you are unsure, please ask a staff member). These gloves are disposable, single use gloves. Please throw them away when you are finished.
  • Make sure you are using the proper gloves for the chemicals you will be working with. (if unsure, please ask a staff member).
  • Test the orange acid gloves and the green Nitrile gloves with nitrogen gun before using.
  • Put on PPE gloves first over the clear Nitrile gloves.


  • Inspect the apron to ensure that there are no tears.
  • Put apron on second.

-Face Shield

  • Put on face shield and make sure it fits comfortably.

-Respirators may be needed under some conditions for additional protection.

  • Check the date on the filter (if older than 1 year, replace).
  • If you put a new filter in the respirator, remember to write the date on the filter.

-PPE should be worn any time chemicals are used

  • Solvents - Nitrile gloves are satisfactory.
  • Acids/Bases – Full PPE should be used.
  • Photoresist Developers – Orange acid gloves are recommended.

-Minimize the number of users at one hood at one time. Try to keep the number of users at one fume hood to 2 max.

  1. Testing the Fume Hood

-Check to make sure that fume hood is working properly

  • Test the fume hood with all the equipment/bottle/hotplates/etc. still in the fume hood.
  • Leave the face/splash guard down when using the hood.
  • Tex wipes – Use a tex wipe at the entrance of the hood and at the base/back of the hood and ensure that there is suction. (PREFERED METHOD) Don’t let go of the tex wipe because it can be sucked into the ventilation system.
  • Air flow meter – Use an air flow meter to ensure that the hood is working. Show this during training, but is not necessary for everyday testing.
  • Remove any tex wipes that my be covering the vents on the counter of the hood.
  • Note that there are small vent holes on the horizontal surface in the front as well as in the back. There are also larger vent holes on the vertical surface in the back. Too many objects in the back, such as bottles and hot plates can block proper air flow.

-If hood is not working properly

  • Check to make sure that the hood has been turned on (switch is located above hood opening and on the left).
  • An alarm will buzz at start up for 10 seconds. If the buzz does not stop after 10 seconds then the fume hood is not working properly.
  • If hood still is not working properly, tell the MiRC staff member, put in a Petit Service Request, and put a “DO NOT USE” sign on the hood.

-If there is any liquid on the fume hood surface

  • Put on Orange acid gloves and test the liquid with pH paper.
  • Acids and bases can be stronger than what is designated with 0-14 pH paper. Caution should be used with testing liquids with pH paper.
  • If an acid/base, and a small spill, wipe up with a tex wipe.
  • If an acid/base, and a large spill, contact a member of MiRC staff.
  • NEVER assume that something is water.

-Explain operation of foot pedal.

  • When to use DI water (for processing and cleaning glassware).
  • When to use city water (for rinsing out waste bottles, diluting acids being poured down drain).
  1. Acid/Base and Solvent Storage

-Where located.

  • Acids in cabinets labeled “A” located near each fume hood.
  • Bases in cabinets labeled “B” located near each fume hood.
  • Solvents are stored by each fume hood.

-Store extra chemical bottles on the top of the chemical storage cabinets, NOT on the floor.

-Have gloves on when getting acids/bases out of the cabinets.

  • Acids may drip down the bottle and get on the outside of the bottle.

-Transportation of bottles.

  • If a bottle is not in the bay that you need, find the chemical in another bay and transport it from one bay to another with the designated carriers.
  • Never carry chemical bottles without the proper carrier.

-What if the chemicals are out?

  • Show the users where to find each of the bullets listed below.
  • Spare acids and bases are located in the storage room, remember to transport the bottles with a carrier.
  • Spare solvents are stored in large containers in the storage room.
  • Solvent bottles can be filled by any user in the storage room.
  • Always look though the other cabinets in the clean room before you request more chemicals from the clean room staff.

-Know where the storage room is and the PPE glove selection chart, where the chemical storage cabinets are, and where and how to refill solvents.

  1. How to Pour Chemicals

-Before you pour any chemicals, do the following:

  • Create a Chemical Warning Label for the chemicals you plan to use before you pour any chemical.
  • Make sure the glass or plastic dishes you plan to use are clean and dry.
  • Make sure that you are using the proper dishes for what chemicals you are using
  • Only Teflon and polypropylene should be used with HF. HF will attack some plastics, especially polyethylene.
  • Rule of thumb: Match the chemical bottle type with the type of container you plan to use.

-Minimize the amount of chemical bottles in the hood at one time.

-Hold chemical bottle with two hands when pouring.

-If you need to measure a chemical, pour the chemical into a small beaker and then pour from the small beaker into the graduated cylinder to measure out the quantity you need.

-If you have left over chemical in the small beaker, dispose of it properly. Never pour any chemicals back into the container from which they came.

-Once you have poured the chemical, use a tex wipe and wipe off the lip and side of the bottle to ensure that no chemical is left exposed on the bottle.

-Throw the tex wipe into the trash.

-Rinse and dry each beaker and graduated cylinder before pouring the next chemical.

-Only a MINIMAL amount of chemical needs to be used. Don’t pour more chemical than you need. Especially with developer and solvents.

-Rinse and dry PPE gloves between pouring different chemicals.

-As a common courtesy let other users working in the fume hood know what chemicals you will be pouring or using.

  1. How to Dispose of Chemicals

-Acids and bases can be put down the sink, and then run the city water for a minute to ensure that the chemicals have been diluted and flushed down the drain.

-Solvents should be put into the solvent waste bin.

-Solvents should NEVER be put down the sink.

-Acids should NEVER be put into the solvent container.

-Chemicals containing lead, cyanide, chromium, chlorophenols, dioxins, mercury, barium, cadmium, beryllium, silver, selenium, tellurium, cannot go down drain and need to be put in a container. environ. health & safety must be called to pick up.

  1. Cleaning Up (General)

-After you have disposed of the chemicals properly, wipe off the counter space where you were working.

-Clean thoroughly and rinse 3 times all glass and plastic ware and put on the pegs to dry.

-Run DI water over the neoprene gloves, dry them thoroughly, and put them away in their proper location.

-Remove all PPE.

-Never leave bottles on the floor or in the fume hood.

-For empty bottles, rinse 3 times, write "WASTE" conspicuously on label of bottle, place on cart in hallway.

-Do not leave behind tex wipes in the fume hood.

-Turn off hot plate when you are doing using it.

  1. Cleaning Up (Chemical Spill)

-If you spill a chemical, ensure that you or others have not been exposed to any of the spilled chemical.

  • If someone has been exposed, rinse the exposed area in the sink or shower for 15 minutes minimum, and stay with the individual for the entire time they are rinsing. (Point out where shower and eye wash stations are located.)
  • Contact clean room staff or the campus police (if staff is not on duty).
  • Seek medical attention.
  • Refer to Emergency Instructions for more details.

-Make sure you have the proper PPE on.

-For a small spill: wipe up with a tex wipe and throw the wipe in the trash.

-For a large spill: clear out the area and inform a staff member. If staff is not on duty contact the Georgia Tech police for assistance. DO NOT try to clean a large spill yourself.

  1. Misc. Information

-Accidents happen, but the more informed we are the better we will be able to handle any situation.

-Users are encouraged to stop any other user who may not be following proper fume hood and chemical handling procedures and inform them of the proper procedure. If the user does not respond in a professional manner and correct their actions right away any member of the MiRC staff should be notified immediately.

-Think about the action you plan to perform and its possible consequences.