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, 4^th edition from Wiley ( or on amazon much cheaper)that focuses more on the health and safety aspects of labs.

 

Lou DiBerardinis

Director, EHS office

MIT

 

 

Suzy,

 

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). 

 

Regards,

Ben

--------------------------------

Ben Owens

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

Fax: 775-784-4553

 

 

 

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
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Particulate protection from a milling machine