The Italian Fire Code: More Oriented Towards a PBD Approach
By: Piergiacomo Cancelliere - PhD, Ministry of Interior – Italian National Fire Rescue and Service (C.N.VV.F.), Italy
Fire safety of residential buildings and activities subjected to fire inspection are difficult tasks, especially when the safety targets have to be adopted in pre-existing buildings or in activities that are going to be modified into more complex ones. Usually, these circumstances show more constraints, and it can be challenging to achieve an acceptable level of fire residual risk by prescriptive fire regulations. Therefore, the Italian National Fire Rescue and Service, in charge of fire safety in Italy, in August 2015, issued a new Fire Safety Code whose design approach is more oriented to fire performance based design rather than prescriptive fire codes. The flexibility of this novel fire design methodology offers a very completed tool for experts in order to design fire safety measures for buildings and activities subjected to fire inspection. This paper highlights the contents and the fire safety strategy design methodology of the new Italian Fire Safety Code. This paper is the short version of [1].
Introduction
Fire codes and regulations play a fundamental role in reducing risks and achieving acceptable levels of fire safety, both in buildings and high hazard facilities.
Most of the Italian activities subjected to fire inspection, such as stores, malls, schools, hospitals, car parking facilities, industrial buildings, are subject to prescriptive fire safety code. As well known, the prescriptive fire codes are consisting of specific requirements which attempt to specify all the different components and measures of the system to provides fire safety for a building or an industrial activity. Nevertheless, the contribution of each requirement to the level of safety provided by the system is not known and the interactions between the components are not generally known or taken into account [2]. In addition, when the safety targets have to be satisfied in already built buildings or industrial activities that are going to be modified into more complex ones, there are more constraints to cope with and it could be difficult to achieve an acceptable level of fire risk using prescriptive based fire codes and regulations. These inherent deficiencies lead to lack of flexibility, conservative outcomes and unnecessary cost burdens.
On 20th of August 2015, the Italian Home Office released the Ministerial Decree 3rd August 2015 that contains a new approach to the fire safety design of activities subjected to fire inspection. The technical Ministerial Decree is titled “Approval of fire prevention technical standards, pursuant to Article 15 of Legislative Decree 139 of 8 March 2006”, but is commonly recognized among Italian fire officers and practitioners as the Italian Fire Prevention Code (IFC) [3].
The IFC, following the fire safety engineering principles, sees the process of fire safety design considering the system as a whole by focusing on the safety targets whether they are life safety, property loss, business interruption, environmental damage or heritage preservation.
Furthermore, IFC gives an holistic approach to fire safety design, guiding the practitioner during the fire design process in choosing the best fire provisions to reduce and mitigate the assessed fire risk to an acceptable level. The international state of the art of fire design codes, such as but not limited to the BS 9999:2008 “Code of practice for fire safety in the design, management and use of buildings” [4], the NFPA 101 “Life Safety Code” [5] , and the International Fire Code 2009 [6] have been considered during the developing stage of the IFC.
Nowadays, actual studies and experiments for understanding fire‐related phenomena increase the capability of the fire engineering community to assess and predict the performance of structures and protection systems when exposed to a fire event [7]. The use of analytical tools such as empirical models, finite element analysis, and computational fluid dynamics, in conjunction with bench top and full‐scale testing has improved the ability of fire practitioners to develop performance based solutions to challenging fire safety design of high‐risk industrial activities or complex buildings [8].
The fundamental assumptions of the IFC are:
- a) in ordinary conditions (no arson, no catastrophic situations), a breakout of a fire in an activity could happen only in one point of ignition;
- b) in any safety design, the risk of fire cannot be reduced to zero; the fire‐safety prevention, protection and management measures provided applying the IFC fire design process ensure a proper selection of the measure that minimize the risk of fire in terms both of occurrence and damages, at a level that could be considered as an acceptable level of safety. This paper highlights and discusses principles and the methods proposed by the IFC for the fire safety design of activities subjected to fire approval and inspection.
IFC fire safety design method
Advance structural engineering as well as material science innovation technologies satisfy the architectural demands to build up complex buildings that cannot comply with fire prescriptive codes. In order to assure an acceptable level of fire safety, risk-based methods could provide an opportunity to determine the quantitative safety level. The main advantage of the risk-based method is the hazard versus safeguard determination both as probability and damage [11].
General design of the IFC fire risk assessment and mitigation strategy is based on the following principles. The first one is the overall applicability of the design procedure that should be specific for each activity subjected to fire inspection. The IFC method is oriented to “Simplicity”: given different choices to achieve the same safety level, the simpler one and the more easily achievable solution, by taking into account also the maintenance features, shall be preferred.
The design is "module" oriented: the complexity of the fire design is split into easily accessible modules, which guide the designer towards the appropriate solutions for any specific activities.
Moreover, IFC has also been standardised and integrated to the fire‐safety and fire protection language of international standards. The code is also fully inclusive: different disabilities (e.g. motor, sensory, cognitive ...), temporary or permanent, of the occupants shall be considered as an integral part of the fire‐safety design. Lastly, the IFC was thought to be easily “updatable”: the document has been drafted in a format that can be easily kept up to date with the continuous improvements in terms of technologies and knowledge available in the fire safety science.
The IFC design method is also “Flexible”: for each fire‐safety project it gives design solutions that are semi‐performance based (the so called “deemed‐to‐satisfy solutions”). These compliant solutions contain prescriptive examples of materials, products, design factors, construction and installation methods, which ‐ if adopted ‐ comply with the performance requirements of the IFC.
If the deemed to satisfy solution could not be put in place, the IFC offers performance based solutions called “alternative solutions”. The alternative solution is any solution that can meet the IFC performance requirements, other than a deemed‐to‐satisfy solution, using the following allowed methods:
– Fire Safety Engineering (FSE);
– Design solution based on innovative technologies products and systems;
– Alternative, national or international, authoritative fire codes or regulations;
– Experimental tests.
In any case, the alternative solution implies that the requested level of performance is, in any case, achieved.
The IFC method requires the scope definition describing the context of the activity pointing out the operating and environment peculiarity of the activity. The following step is choosing the safety objectives: life safety, property protection and safeguard of the environment. The third step is to identify and analysing the activity fire risks by means of a systematic evaluation based on fire hazard related factors. Then to prioritise the risks in order to tackle them by means of fire preventions, protections and management measures, is required. The IFC final goal is aimed to achieve life safety, property protection and the safeguard of the environment in case of fire. According to the IFC document, the risk assessment is followed by the evaluation of the following simplified parameters:
– Rlife, risk profile concerning human life safety;
– Rpro, risk profile concerning the property protection;
– Renv, risk profile concerning the protection of the environment from the effects of the fire.
The fire risk profile connected to life safety – Rlife – is evaluated as a function of the growth rate of a fire in a building compartment. The behaviour of building occupants in response to a fire is defined. The fire growth is a square type (typical parameter varies from 1, that represents a slow fire growth, to 4 that is an ultrafast fire growth). The occupant characteristics are summarized into the following groups:
– A occupants awake and familiar;
– B occupants awake but unfamiliar;
– C occupants that could be asleep;
– D occupants receiving medical care;
– E occupants in movement (stations, tunnels).
The occupancy characteristics chosen by the IFC are the same of those contained in BS 9999 [4]. Rpror is based on the building strategic nature or heritage, cultural, architectonic, or artistic value coupled to the significance of the building contents, such as business continuities or property protection. The last simplified risk parameter Renv takes into consideration the risk of environmental damage or environmental contamination during and after the outbreak of a fire. Renv is assessed also taking into account the emergency response management. Figure 1 highlights the general fire safety design method proposed by the IFC.
Figure 1. IFC fire safety design method
Conclusion
The IFC structure is consistent with the international state of the art of the fire safety science and engineering. Compared to the traditional prescriptive fire regulations, the performance‐based approach implies a wide range of advantages such as flexibility in the choice of the most appropriate design solution consequent to a more realistic definition of fire scenarios. On the contrary, performance‐based design requires more expertise and knowledge in this field, especially when the fire or evacuation numerical models are needed. In this case, in fact, the sensibility of the designer can strongly affect the results and therefore the proposed solution. The challenge of the next few years will be to guarantee the reliability of the integrated technology systems according to the RAMS approach (i.e. Reliability, Availability, Maintainability and Safety) in order to improve the safety performance.
References
- Cancelliere et al. “Italian Hybrid Fire Prevention Code”, WIT Transactions on The Built Environment, Volume 174, pp 107-117
- Armin Wolski, Nicholas A. Dembsey, Brian J. Meacham “Accommodating perceptions of risk in performance‐based building fire safety code development”, Fire Safety Journal 34 (2000) 297‐309
- DECREE OF THE MINISTER OF THE INTERIOR 3 August 2015 “Approval of fire prevention technical standards, pursuant to Article 15 of Legislative Decree 139 of 8 March 2006”.
- BS 9999:2008 “Code of practice for fire safety in the design, management and use of buildings”, British Standards Institution (BSI) http://www.bsigroup.com/.
- NFPA 101 “Life Safety Code”, National Fire Protection Association http://www.nfpa.org.
- International Fire Code 2009, International Code Council http://www.iccsafe.org/.
- Guarascio, M., Lombardi, M., Rossi, G., & Sciarra, G. (2007). Risk analysis and acceptability criteria. WIT Transactions on the Built Environment, 94.
- Spinardi G. (2016). Fire safety regulation: Prescription, performance and professionalism. Fire Safety Journal 80 (2016) pp. 83-88.
- V. Weyenbergea, P. Crielc, X. Deckersa, R. Caspeelec, B. Mercia, Response surface modelling in quantitative risk analysis for life safety in case of fire, IAFSS 2017 conference proceedings.