Ben is correct in that "fume " hoods is an incorrect term that many have been trying to change for years. It is designed to contain vapors and gases not particulates or fumes. The transport velocity needed would be 3-4000 fpm in the duct and most systems are designed for a tduct velocity of 1500 fpm. So particles will settle out and clog the system.
The ACGIH vent manual describes these conditions. Another valuable reference is ANSI standard Z9.5-2012" laboratory ventilation". Several colleagues and I also have a book, Guidelines for Lab design, 4th edition from Wiley ( or on amazon much cheaper)that focuses more on the health and safety aspects of labs.
Director, EHS office
When designing a ventilation system to capture and transport toxic particulate such as lead particulate, a particulate filter (perhaps a HEPA) will generally be located as close as possible to the capture point to minimize contamination of the ducting and HVAC system. Proper transport velocity Is also required to prevent settling out of the particulate. One commonly used ventilation design guide is the ACGIH publication Industrial Ventilation: A Manual of Recommended Practice for Design (http://www.acgih.org/store/ProductDetail.cfm?id=2235).
Assistant Director, Laboratory Safety
Environmental Health and Safety Dept., MS 328
University of Nevada, Reno 89557
Office Phone: 775-327-5196
Cell Phone: 775-843-2113
From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL.EDU] On Behalf Of Suzy Arnette
Sent: Wednesday, March 04, 2015 11:58 AM
Subject: [DCHAS-L] Particulate protection from a milling machine
We have a lab that uses their milling machine in the chemical fume hood to protect the researchers from lead particulates in the material they are working on. We are now getting push back from our HVAC folks about this process because they feel the particulates are clogging our heat capture coils.
Do you any of you have similar processes? Have you received push back from HVAC?
Suzy Arnette, PhD
Lab Safety and Design Manager
Radiation Safety Officer
Boise State University
Environmental Health, Safety, and Sustainability
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