Ductless Hoods

Emerging Trends in Laboratory Ventilation

ACS Fall 2009 National Meeting Washington DC August 15- 20, 2009

Erik Talley / Matthew Brinton Environmental Health and Safety

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

What is a “Ductless Hood”?

Enclosure + Fan + Filter = Ductless Hood

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

No!!!!

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

Design Limitations   Recirculation of exhaust air is

potentially dangerous. –  Limited Filter Capacity (saturation,

breakthrough, stripping)   Filter Changes (handling of used

filters, including hazardous waste disposal as a hidden cost)

  Poor design   Chemical hoods are used for more

than just chemical containment (e.g. fire, explosions)

  Not typically maintained by Facilities

  User Knowledge/Misuse

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

Why consider ductless? (building limitations)

Centre Georges Pompidou Existing External Ducts Baker Pavilion

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

Why consider ductless? (continued)

  Increased safety for benchtop work or equipment.

  Standard chemical hood design interferes with needs (e.g. dust weighing)

  Insufficient need to justify infrastructure/operational costs of ducted hood (installation cost, space needs) .

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

Why consider ductless? (continued)

  Energy efficiency (A single ducted chemical hood running 24/7/365 uses as much energy as a single-family home.)

  Pollution capture

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

Hazard Assessment

  An Industrial Hygienist must conduct a comprehensive Hazard Assessment including: –Type of Hazards –Frequency of Use: Dose –Duration of Use: Dose –Hazard Generation

Characteristics –Effluent Characteristics

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

Limited Filter Applications   HEPA

–  Powder weighing, nanoparticulates, etc.

  Adsorbent Cartridges –  Nuisance odors –  Low toxicity chemicals –  Applications where chemical

usage is: •  limited (volume and time) •  consistent •  controllable

  Dual Filters –  Animal Surgeries

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

Controls

  Service Contract   Connect to house

exhaust if possible (canopy, thimble)

  Minihelic Pressure Gauge (HEPA), Flow Monitor, Vapor Sensor

  Signage   Training   Inspections

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

Case Study - Gross Anatomy   Plastination

–  New Process –  Limited Use –  Single chemical hazard (organotin

compound) –  Very Limited Space

  Hood Selection –  Activated carbon

  Controls –  Air exhausted to outside after

being filtered –  Limited Access –  Training –  Inspection

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

Case Study - Clinic   Urology

–  Endoscope disinfection machine

–  Located in interior of building with no exhaust options

–  Gluteraldehyde (5%) Solution   Hood Selection

–  Carbon filter hood designed specifically for the endoscope machine

  Controls –  Service Contract –  Labeling –  Training

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

Case Study – Laboratory   Epigenomics Core

Laboratory –  Chemical use limited to sample

preparation •  ~125 ml total chemical usage/month

–  Hood use approximately 30-60 minutes a week

  Hood Selection –  Dual Filter

  Controls –  Limited Access –  Labeling –  Service Contract –  Training

Environmental Health and Safety www.med.cornell.edu/ehs

ehs@med.cornell.edu 212-746-6201

Resources