Date: Thu, 11 Mar 2010 13:49:10 -0800
Reply-To: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: Chuck Cooper <cooperc**At_Symbol_Here**PDX.EDU>
Subject: Re: Cryogenics face shield?
In-Reply-To: <8B2D3AEB-43F4-4AAC-BD15-0153E9D7CC28**At_Symbol_Here**uvm.edu>

Liquid nitrogen boils at -321 =B0F,  normal skin temperature is around  

90 =B0F, thats over 400 =B0F difference. A splash of  LN2 is not 
actually  
going to touch the skin because of the Leidenfrost effect,  a  
phenomenon in which a liquid, in near contact with a mass  
significantly hotter than the liquid's boiling point, produces an  
insulating vapor layer. Your likely to be harmed from LN2 only if your  

skin is continuously exposed. See these demonstrations:

Hand vs. Liquid Nitrogen and the Leidenfrost Effect
http://www.youtube.com/watch?v=gjsMV1MglA4

Mr Robinson Drinks Liquid Nitrogen!
http://www.youtube.com/watch?v=UHjC9G03bdE&NR=1

mrhelix drunks liquid nitrogen
http://www.youtube.com/watch?v=-FkPbi4-ZTM



Chuck Cooper
Environmental Health and Safety
Portland State University
503-725-4312
cooperc**At_Symbol_Here**pdx.edu



On Mar 11, 2010, at 9:44 AM, Ralph Stuart wrote:

> A lab tech writes:
> Do you have a recommendation for an appropriate face shield that  
> people should be using when working with LN2? I've been searching  
> the web and it's hard to find a specific recommendation for a face  
> shield to be worn with cryogenics. I don't see any guidelines on  
> OSHA that point to any particulars and nothing on the Cryogenic  
> Society of America's site either. I would appreciate your assistance.
>
> Does anyone have any favorites they'd like to recommend?
>
> - Ralph
>
> Ralph Stuart, CIH
> Environmental Safety Manager
> University of Vermont
> Environmental Safety Facility
> 667 Spear St. Burlington, VT  05405
>
> rstuart**At_Symbol_Here**uvm.edu
> fax: (802)656-5407
>

Previous post   |  Top of Page   |   Next post



The content of this page reflects the personal opinion(s) of the author(s) only, not the American Chemical Society, ILPI, Safety Emporium, or any other party. Use of any information on this page is at the reader's own risk. Unauthorized reproduction of these materials is prohibited. Send questions/comments about the archive to secretary@dchas.org.
The maintenance and hosting of the DCHAS-L archive is provided through the generous support of Safety Emporium.