Post on 26-May-2015
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
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