Given the growing interest in the use of fire safety assessment techniques for buildings, a number of organizations are offering guidance documents that are useful to designers and approval authorities. These guides are not risk assessment methodologies or risk analysis techniques. Rather they are aimed at assisting practitioners in selecting the appropriate methodology for each individual building and ensuring that the risk assessment and approval processes are carried out with appropriate engineering approach.
SFPE Engineering Guide: Fire risk assessment
The SFPE Engineering Guide is aimed at qualified professionals involved in the design and assessment of the fire safety of buildings and/or processes. The document provides guidance on the selection and use of risk assessment techniques and provides a recommended process to follow. The guidance does not specify specific methods or techniques for risk assessment, but provides recommendations on the following issues:
- A recommended fire risk assessment process (Figure 1 [1])
- Tools that can be used for hazard identification
- Risk assessment data sources
- Consequence modelling approaches
- Fire risk calculation methods
- Fire risk assessment documentation
The SFPE Guide is structured to follow the flowchart presented in Figure 1 [1], providing guidance and information at each step in the process. This information is supported by many references and a comprehensive list of information sources for further reading for each step of the risk assessment process.
NFPA 551: Guide for the evaluation of fire risk assessments
The NFPA 551 guide was developed as evidence that fire risk assessment methods are increasingly being used in the development of fire safety solutions for buildings and other facilities. This document is aimed at those responsible for approving or evaluating fire safety decisions based on fire risk assessment. The guidance is suitable for building officials, fire authorities or other bodies assessing or approving projects where there is a fire risk assessment. Like the SFPE Engineering Guide, NFPA 551 does not specify specific fire risk assessment methods or set acceptance criteria. Rather, it specifies the technical review and documentation process to be used by the assessors (Figure 3).
NFPA 551 defines five categories of risk assessment methods in order of increasing complexity:
• Qualitative methods
• Semi-qualitative criteria-based methods
• Semi-qualitative consequence-based methods
• Quantitative methods
• Cost-benefit methods
The guidance emphasizes the importance of identifying the objectives of any risk assessment and other factors that need to be considered. For each of the five categories of methods, the characteristics of each approach are identified, inputs and outputs issues, assumptions and limitations, choice of fire scenarios, and degree of uncertainty are discussed.
BS 7974-7: Probabilistic fire risk assessment
The British Standards Institute (BSI) provides a number of fire-related design standards. A framework for the application of fire safety engineering principles to the design of buildings is provided within BS 7974. This document is supported by the PD 7974 Published Document series, Parts 0 to 7. The final document, Part 7, provides guidance on the probabilistic assessment of the risk in buildings. The paper provides a risk assessment framework commensurate with a number of approaches. Specifically, the document provides guidance on acceptance criteria for life safety and financial evaluations that can use either comparative or absolute methodologies.
The absolute criteria for individual risks and societal risk are provided. The logic tree is illustrated using both event and fault trees. An evaluation methodology using complex analysis techniques is also provided. The appendix to this document provides guidance on the probability of fire occurrence depending on the type and purpose of the building. In addition, the average damaged area and damage distribution are provided.
ISO 16732-1: Fire safety engineering – fire risk assessment
ISO 16732-1 provides the conceptual basis for fire risk assessment, specifying the principles that underlie the quantification and interpretation of fire risk. The principles and concepts described in the standard can be applied to any fire safety purpose, including life safety, property protection, business continuity, heritage protection and environmental protection.
The principles of fire risk discussed in the standard apply to all fire-related phenomena and consumer applications, meaning that the principles can be applied to all types of fire scenarios. The principles underlying risk quantification are presented in terms of steps to be taken when performing a risk assessment. These steps are first placed in the context of overall fire risk management and then explained in the context of fire safety engineering.
The use of scenarios and the characterization of probability (or the closely related measure of frequency) and consequences are then described as steps in fire risk assessment, resulting in the quantification of combined fire risk. Guidelines are also provided for the use of the information generated, i.e. for the interpretation of fire risk.
The standard also provides guidance on uncertainty analysis methods in which the uncertainty associated with fire risk assessment is determined, and the implications of that uncertainty are interpreted and evaluated. As described in ISO 16732-1, risk management includes risk assessment, but usually also includes risk treatment, risk acceptance and risk communication (Figure 4).
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References:
[1] http://fire-techinfo.com – Fire risk assessment in buildings – a general overview
[2] http://fire-techinfo.com – Fire risk assessment in buildings – identification and analysis of hazards, events and scenarios
[3] http://fire-techinfo.com – Fire risk assessment in buildings – qualitative and quantitative methods
[4] http://sfpe.org – Аn оverview of аpproaches and resources for building fire risk assessment
[5] SFPE Engineering Guide – Fire Risk Assessment, Society of Fire Protection Engineers
