By Peter E Jackman
Testing plays an important role in developing fire safety standards for the petrochemical and related industries
The more people congregate under one roof for accommodation or work, the greater the need to protect them from predictable and possibly preventable accidents such as catastrophic fires.
This problem is usually addressed via codes of compliance. Major components of these are the construction of barriers to contain fire and the building of structures that can resist its impact. Producing common test procedures and methods of calculating how construction may satisfy such tests is the role of sub committee 2 (SC 2) of the International Organization for Standardization’s TC 92 fire safety group (ISO/TC 92/SC 2).
The sub committee is close to putting in place a new range of ISO test procedures for containing and resisting fire. These aim to bridge the gap that exists between existing trading blocks, with well established procedures, while also providing solutions for countries or blocks that have not generated fire safety codes of their own.
The work of the sub committee goes beyond producing harmonised versions of existing test methods. In the recent past it has been recognised that there are new fire protection systems, requiring new test methods. Furthermore, there is recognition that the severity of a fire can vary in different applications. These in turn need new test procedures to reflect the different conditions. It is these new procedures that have had to be generated or adapted by SC 2.
Perhaps one of the biggest challenges came as a result of recognising that the size of testing facilities in use restricted the safe application of the outputs of these tests. Many applications could not be tested, generally because of the scale of the test and the need to consider the construction itself. Methods of calculating how these larger constructions might behave needed to be put in place, and SC 2 was in a good position to know what data inputs and outputs might be expected.
Predicting the behaviour of a structure when exposed to real fire – where the exposure conditions are the product of the actual fire load and ventilation conditions – remains the responsibility of TC 92/SC 4, (fire safety engineering).
SC 2 has eight active working groups, each one taking responsibility for a different aspect of the work. The most established of these is working group 1. This working group has been responsible for the generation and maintenance of the basic fire resistance testing standard, ISO 834; now being produced in multiple parts. The latest standard to be undertaken by working group 1 is ISO 834: Part 10 which is a special method for evaluating the contribution intumescent coatings make to the fire resistance of steel structural members. This has also led to Part 11, which gives a method for extrapolating the test results of these tests, incorporating a new 3D computer model generated by International Fire Consultants.
Fire test methods for fire doors, and more recently fire-resisting glazing, has been the responsibility of working group 3. While the test for fire doors (ISO 3008) is a simplified version of the EN test, the new test for glazing (ISO 3009) is the first standard in the world to consider testing sloped glazing.
Buildings worldwide are seeing an increase in the use of duct work, either for heating buildings in the northern climates or cooling buildings in the southern or equatorial regions. Preventing these ducts from compromising any attempt to contain a fire is the responsibility of working group 4. Its responsibility is to ensure there are common worldwide tests for both ducts and dampers. Working group 4 has recently published a method for evaluating intumescent dampers, a brand new technology for stopping the spread of fire in ducts.
Working group 5 is charged with the task of producing a test procedure for roofs, with the objective of either keeping fire in, or out.
Like duct work, all buildings now experience a massive increase in the use of pipes and cables and working group 6 is generating standards that evaluate the degree to which these services cause the fire containment strategy to be destroyed. A brand new approach is being evaluated in working group 6, whereby standard conductors are used in lieu of ‘real’ cables and pipes.
Working group 8 has been formed at the request of the petrochemical industry. In this industry, the fire exposure can be magnitudes greater than those experienced in normal building fires and working group 8 has produced a harmonized ‘jet-fire’ test that simulates the fire attack from ruptured petroleum pipe work. This is probably the most spectacular test from within SC 2’s range of fire tests. The Buncefield fire in the UK, just over a year ago, demonstrated the intensity a petrochemical fire can generate. The testing method was originally developed to establish how structural members and valves can be protected against extreme events. More recently the test has been adapted to measure how protected walls can contain such fires, including penetration seals.
Neither working group 2 or working group 7 have responsibility for any test methods. Working group 2 is the committee charged with the responsibility for generating calculation methods for use when testing is impractical, or even impossible. It has produced a number of technical reports, giving guidance on the generation of data for modelling purposes or even harmonizing methods of calculation.
Working group 7 is tasked with looking to the future. The current test methods, the instrumentation and criteria have their roots many decades ago. Working group 7 is making recommendations to generate appropriate updates for bridging the gap to the future.
The catalogue of standards under SC 2’s control is now extensive and it continues to keep its portfolio up to date. Should any country in the world look to put standards in place to support its own fire safety codes, it should not need to look any further than ISO for such test methods.
Peter E Jackman is Technical Director of International Fire Consultants Ltd (United Kingdom). In addition to being the convenor of working group 7 in ISO, he has attended ISO/TC 92/SC 2 working group meetings continuously since 1975.