Zettl Group Safety Talk ~Fume Hoods~

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Zettl Group Safety TalkFume Hoods

• 09/28/06
• Takashi Ikuno

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Define Fume Hood
From Fact Sheet by EHS, UCB

• One of the most important safety devices in a
  laboratory is a properly functioning
  fume hood.
• The fume hood protects users from inhaling
  chemicals by constantly pulling air into the hood
  and exhausting it out of the building.
• Fume hoods also provide protection in the event
  of an explosion or fire.

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Situations

• When handling chemicals with significant
  inhalation hazards such as toxic gases, toxic
  chemical vapors, volatile radioactive material,
  and respirable toxic powders
• When carrying out experimental procedures with
  strong exothermic reactions
• When handling chemicals with significant vapor
  pressure
• When chemical vapors generated could cause a fire
  hazard
• When working with compounds that have an
  offensive odor

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Safety Wear

• Goggles
• Wear appropriate safety glasses, goggles, or face
  shields at all times where chemicals are stored
  or handled.
• Groves
• The proper gloves will prevent skin absorption,
  infection or burns.
• Lab Coat or Apron
• Wear a lab coat or apron, cover legs and feet (no
  sandals or open-toed shoes)

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Air Velocity

• To capture vapors adequately, a fume hood must
  provide an average face velocity of gt100 feet per
  minute.
• However, excessive air velocities can cause
  turbulence that may bring the contaminants back
  into the user's breathing zone.

• The Office of Environment, Health Safety (EHS)
  checks campus fume hoods approximately every six
  months to verify that the air velocity at the
  work opening is within an acceptable range.
• The air velocity measurements are noted on the
  hood. EHS also performs a smoke test at least
  once a year to verify inward air flow.

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Proper Sash Use 1

• Position sashes at the arrows to ensure proper
  airflow velocities at the work opening.
• Adjust the sash to shield yourself from splashes
  or flying objects.

• Never close non-bypassed hoods completely. Leave
  at least a two-inch sash opening, particularly if
  flammable materials are present in the hood.

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By-pass hood
Auxiliary air hoods
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Proper Sash Use 2

• Keep all work at least 6 inches inside the hood.
  The capture ability of a fume hood may not be
  100 at the front of the hood.
• Never lean your head inside the fume hood when
  chemicals are present

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Clean and Organize

• Minimize storage. Do not take up hood space and
  block ventilation by storing unused equipment or
  chemicals in hoods.
• Prevent pollution. The chemical vapors generated
  in most hoods are exhausted into the atmosphere.
  To minimize pollution, seal all chemical
  containers not in use. Never use the hood to vent
  excess chemical waste.
• Remove old experimental glassware and clutter.
  Wipe up spilled chemicals or residues. Make sure
  you can see through the glass sash.

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Etc.

• Do not heat perchloric acid in standard fume
  hoods. Perchloric vapors may create explosive
  perchlorates in the ductwork. Contact EHS if you
  are performing perchloric acid digestions.
• Do not adjust the damper. Doing so may adversely
  affect fume hoods in other rooms.

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124 Birge
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260 Birge
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274 Le Conte
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Berkeley Lab's High Performance Fume Hood Reduces
Energy Use by 50 Percent

• More than 500,000 fume hoods are used in the
  United States
• The devices can use a lot of energy-running 24
  hours
• New energy-efficient fume hood technology
  developed by LBNL is expected to reduce the
  energy-intensive demands of laboratory
  ventilation systems.
• Berkeley Laboratory's promising new fume hood
  technology reduces airflow requirements by 50 to
  70 percent while maintaining or even enhancing
  worker safety.
• The new technology could save 8,000 gigawatthours
  of electricity in the United States. The annual
  electricity cost savings per hood is about
  2,100.

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Dont Forget !

• Wear Goggles, Gloves, and Lab coat
• Never lean your head inside the fume hood
• Minimize storage
• Wipe up spilled chemicals or residues
• Remove old experimental glassware and clutter
• EHS 642-3073