Date: Thu, 28 Jul 2011 17:07:28 -0700
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: "Stephen W. Hemperly" <Steve.Hemperly**At_Symbol_Here**HITACHIGST.COM>
Subject: Re: Lessons learned with NMR units.
In-Reply-To: <3FC2A64C5F1C134FB55DD967FCF28FB31609AED8BF**At_Symbol_Here**>

It my experience, the key issues are establishing a "safety zone" around
the NMR unit  from which ferromagnetic tools and wearers of pacemakers &
medical implants vulnernable to elevated static magnetic fields are to be
excluded.  Per the ACGIH TLVs for static magnetic fields, the wearers of
certain medical devices should not be exposed to static magnetic fields
exceeding 0.5 mT or 5 gauss.   Warning signage and other means can be used
to delineate a so-called 5 gauss "safety zone" line inside of which medical
device wearers and unsecured ferromagnetic items should not be permitted.

Typically, the size of the significant static magnetic fields is much
smaller around NMR units than that found in medical environments around
MRIs, but some of the same safety principles apply.  The ACR Guidance
Document for Safe MR Practices: 2007 found at the following link is
informative with the understanding that not all of the safe practices
described (and imposed) for MR(I) units are directly applicable to NMR
units (at least in my experience).

I am aware of a couple of NMR and/or superconducting magnet-related
incidents that occurred in a research facility at which I worked some years
ago.  Let me know if you want to hear more about them -- fortunately, no
one was injured -- but some physical damage was done in at least one case
-- and I suspect at least one person's pride was a bit bruised.

Best regards,


Stephen Hemperly, MS, CIH, CSP, CLSO
Office: (408) 717-7704; Fax: (408) 717-9058
Mobile: (925) 818-8052
Advisory Industrial Hygienist
Environmental Health and Safety
Hitachi Global Storage Technologies, Inc.
3403 Yerba Buena Road - Office 2536-01
San Jose, CA 95135-1500

None of us is as strong as all of us.
AIHA and ASHRAE member
Industrial hygienists are scientists and engineers committed to protecting
the health and safety of people in the workplace and the community.

             Regina Frasca                                                 
             Sent by: DCHAS-L          DCHAS-L**At_Symbol_Here**LIST.UVM.EDU                
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                                       [DCHAS-L] Lessons learned with NMR  
             07/28/2011 01:40                                              
             Please respond to                                             
              Discussion List                                              

Any good lessons learned from the installation or operation of an NMR from
a safety standpoint.  We are just about to start installing a new unit and
besides the manufacture specs and my CIHÕs recommendations,  I wanted to
reach out there and see if anyone has any good tidbits.

Regina M. Frasca, NRCC-CHO
Cal State University San Marcos
Director of Risk Management & Safety
Work: 760-750-4502
Fax:    760-750-3208
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