Abstract

References
1.Bacharach, Inc. (1992 , November). The unseen menace. A pocket guide to the atmospheric hazards of a confined space . New Kensington, PA : Author .
2.
Cable
J.
(2006 , September 21). Nitrogen: The silent killer . Retrieved April 4, 2008 , from www.occupationalhazards.com/Issue/Article/38471/Nitrogen_The_Silent_Killer.aspx.
3.
Gill
J. R.
Ely
S.
Hau
Z.
(2002 ). Environmental gas displacement . Retrieved April 5, 2008 , from www.erowid.org/references/refs_view.php?A=ShowDocPartFrame&ID=7000&DocPartID=6388.
4.GT&S, Inc. (2007 , September 13). Nitrogen, cryogenic liquid: Material safety data sheet . Retrieved April 6, 2008 , from http://208.223.216.204/gtsgas/msds/msdata/MGI16626.pdf.
5.MSA: Mine Safety Appliances Company. (2001 , November). Closing in on confined spaces: A primer on hazards and equipment . Retrieved April 6, 2008 , from www.discountsafetygear.com/gas-detectors-general-information.html.
6.
Naranjo
E.
(2007 , December 1). Oxygen deficiency: The silent killer. Responder safety . Retrieved April 6, 2008 , from www.respondersafetyonline.com/500/Issue/Article/False/77598/Issue.
7.Occupational Safety and Health Administration. (1998 , December). Permit required confined spaces 1910.146 . Retrieved April 5, 2008 , from www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=1099.
8.
Rekus
J.
(1999 , June). Confined spaces: Is 19.5 percent oxygen really “safe”? Occupational Hazards , 61 (6 ), 49 , 50 , 52 , 56 .
9.Spectra Gases, Inc. (2005 , April 4). Nitrogen: Material safety data sheet . Retrieved April 6, 2008 , from www.spectragases.com/content/upload/AssetMgmt/PDFs/MSDS/pure%20gases/MSDS_Nitrogen-1018_121305.pdf.
10.Stanford Linear Accelerator Center. (2006 , October 9). Cryogenic and oxygen deficiency hazard safety (chapter 36) . Retrieved April 6, 2008 , from www-group.slac.stanford.edu/esh/eshmanual/pdfs/ESHch36.pdf.
11.University of Bath. (2002 , 2005). Cryogenic materials: The risks posed by using them . Retrieved April 6, 2008 , from www.bath.ac.uk/internal/bio-sci/bbsafe/asphyx.htm.
12.U.S. Chemical Safety and Hazard Investigation Board. (2003 , June). Hazards of nitrogen asphyxiation (Safety Bulletin 2003–10-B) . Retrieved March 24, 2008 , from www.csb.gov/safety_publications/docs/SB-Nitrogen-6-11-03.pdf.
