Page 1 of 7 First Revision No. 7-NFPA 551-2014 [ Section No. 2.2 ] 2.2 NFPA Publications. National Fire Protection Association, 1 Batterymarch Park, Quincy, MA 02169-7471. NFPA 101A, Guide on Alternative Approaches to Life Safety, 2013 2016 edition. NFPA 550, Guide to the Fire Safety Concepts Tree, 2012 edition. Fire Protection Handbook, 20th edition, 2008. SFPE Handbook of Fire Protection Engineering, 4th edition, 2008. Submitter Full Name: Kristin Bigda Organization: National Fire Protection Assoc Submittal Date: Tue May 06 10:43:59 EDT 2014 : Reference update.

Page 2 of 7 First Revision No. 6-NFPA 551-2014 [ New Section after 3.3.8 ] 3.3.9 Hazard. A condition that presents the potential for harm or damage to people, property, environment, mission, or cultural heritage. Submittal Date: Fri May 02 12:07:48 EDT 2014 Committee Statement: New definition clarifies the use of the term 'hazard' throughout the document.

Page 3 of 7 First Revision No. 5-NFPA 551-2014 [ Section No. 3.3.12 ] 3.3.13 Probability. The likelihood of an event occurrence as expressed as a number between 0 and 1, and the basis of which is often expressed over a period of time or number of trials. Submittal Date: Fri May 02 11:47:53 EDT 2014 Committee Statement: Response Message: To provide clarity on the definition of the term as it is used throughout the document.

Page 4 of 7 First Revision No. 2-NFPA 551-2014 [ Section No. A.5.2.5 ] A.5.2.5 The risk matrix method was developed in the 1960s as a systems safety technique for military systems and is presently documented as MIL-STD-882D 882E. In this approach, each hazard is assigned a probability level and a severity category. Table A.5.2.5(a) and Table A.5.2.5(b) are adapted from corresponding tables in MIL-STD-882D 882E. A risk matrix utilizes the probability levels and severity categories to represent the axis of a two-dimensional risk matrix such as shown in Figure A.5.2.5. Table A.5.2.5(a) Probability Levels Probability Description Frequent Likely to occur frequently, experienced (p >0.1) Probable Will occur several times during system life (p > 0.001) Occasional Unlikely to occur in a given system operation (p > 10-6 ) Remote So improbable, may be assumed this hazard will not be experienced (p < 10-6 ) Improbable Probability of occurrence not distinguishable from zero (p ~ 0.0) Table A.5.2.5(b) Severity Categories Severity Negligible Marginal Critical Impact The impact of loss will be so minor that it would have no discernible effect on the facility, its operations, or the environment. The loss will have impact on the facility, which may have to suspend some operations briefly. Some monetary investments may be necessary to restore the facility to full operations. Minor personal injury may be involved. The fire could cause localized environmental damage. The loss will have a high impact on the facility, which may have to suspend operations. Significant monetary investments may be necessary to restore to full operations. Personal injury and possibly deaths may be involved. The fire could cause significant reversible environmental damage. The fire will produce death or multiple deaths or injuries, or the impact on operations will be disastrous, resulting in long-term or permanent Catastrophic closing. The facility would cease to operate immediately after the fire occurred. The fire could cause significant irreversible environmental damage. Figure A.5.2.5 Risk Matrix.

Page 5 of 7 Submittal Date: Fri May 02 09:22:22 EDT 2014 : Reference update.

Page 6 of 7 First Revision No. 1-NFPA 551-2014 [ Section No. B.1.4 ] B.1.4 U.S. Government Publications. U.S. Government Printing Office, Washington, DC 20402. MIL-STD-882D 882E, Standard Practice for System Safety., U.S. Department of Defense, 10 February 2000 11 May 2012. Submittal Date: Fri May 02 09:14:23 EDT 2014 : Reference update.

Page 7 of 7 First Revision No. 3-NFPA 551-2014 [ Section No. B.2.2 ] B.2.2 Other Publications. Engineering Guide to Fire Risk Assessment, 2006. Hasofer, A.M., V.R. Beck, and I.D. Bennetts, Risk Analysis in Building Fire Safety Engineering, Butterworth-Heinemann, Oxford, England, 2007. Ramachandran, G., & David Charters, Quantitative Risk Assessment in Fire Safety, Spon Press, 2011. System Safety Analysis Handbook, 2nd edition, System Safety Society, Unionville, VA, 1999. Yung, D., Principles of Fire Risk Assessment in Buildings, John Wiley & Sons Ltd, Chichester, England, 2008. What-If Analysis. 1999. System Safety Analysis Handbook, 2nd edition. Unionville, VA: System Safety Society, pp. 301 303. Yung, D., G. V. Hadjisophocleous, and G. Proulx. 1997. Modeling Concepts for the Risk-Cost Assessment Model FiRECAM and Its Application to a Canadian Government Office Building. Melbourne, Australia: Proceedings of the 5th International Symposium on Fire Safety Science, pp. 619 630. Supplemental Information File Name B.2.2.docx Description B.2.2 Submittal Date: Fri May 02 11:37:06 EDT 2014 : Reference Update.