September 6, 2001 Ratification of the criteria for Britain's Construction Products Directive (CPD) has suffered another blow, following the move by Standing Committee on Construction to postpone until December a decision on the Euroclass Tables for Cables.
This is causing frustration among cable manufacturers trying to plan fire safety measures, and leading to questions on whether the CPD is meeting its objective of providing a common technical specification for health and safety in construction works. There are claims now that the interests of the cabling industry are taking precedence.
The European Union (EU) Enterprise Commission had stipulated that cabling was to be included in the overall Euroclasses system that makes up the bulk of the CPD, classifying materials under requirements, such as fire performance. Initial classification criteria was for cables' reaction to fire under the categories of ignition, flame spread, rate of heat release and fire growth rates. Acidity, corrosivity, total smoke production and smoke production rates were all likely to have to meet a voluntary declaration.
Europacable, however, put forward an amended proposal detailing a separate classification system for power, control and communication cables--amalgamating the three groups rather than, as in the United States, developing specific criteria for power and communications cables.
This request had received a draft Commission decision, giving cabling a specific set of fire performance criteria within the CPD (provisionally titled Table 3) and looked set to proceed; the only areas to be agreed being test methods and the specific criteria under the Euroclass system.
Uncertainty breeds frustration
But now changes and modifications have been submitted, and the EU's Fire Regulator must consider these before further progress can be made. And because the initial values put forward for criteria such as smoke production and heat release have now changed, manufacturers--many of whom are putting every effort into producing cables with improved fire resistance--are becoming increasingly frustrated.
Cabling requirements in new buildings can no longer be regarded as an afterthought. The rapid increase in demand--more complex ICT systems, extensive voice systems and even building monitoring equipment--means that cables now have to be viewed as a permanent part of a building in the way that conventional construction materials are.
Table 3 is a major step forward in recognizing cables for their properties as well as their performance, but we need to be sure we recognize and prioritize the appropriate criteria.
Fire in cabling systems is a very real risk for the modern building, particularly where the majority of the cables are hidden from view in confined spaces; between floors and ceilings, for example. Heat build-up is rapid in these spaces, and the necessity for all areas of the building to have cable service equally allows fire to spread, potentially unchecked, in these hidden areas. But these areas are used almost exclusively for data cabling, rather than power cables.
Europacable's reclassification of the criteria intended for Table 3 raises some interesting questions about building safety. Lowering the thresholds for total heat release and rate of heat release, for example, could see cables passed for approval that could significantly increase the speed with which a fire takes hold.
Ways to control fire spread
We should be looking to minimize the rate at which a fire spreads, allowing a building's occupants to exit quickly and safely in a fire situation. And while people�s safety should take precedence, if possible, we should try to minimize damage to the fabric of the building. Controlling fire spread achieves both.
The way forward is perhaps to take a lead from the U.S., where separate classifications have been developed for power and data cables, reflecting the fact that they are used in varying quantities and different areas of the building. Ignoring such a fundamental point questions whether health and safety issues are really being given the priority they deserve.
To do this and be accountable to a value table focusing on the specific requirements for each type of cable gives manufacturers the flexibility and freedom they need to adapt and improve cables' fire performance qualities.
The original criteria were satisfactory on this front and were within sight of being ratified. Now we have a further delay. Perhaps the time has come to decide on what really constitutes public safety.
(Note: The Construction Products Directive was incorporated into British law in 1991. Its aim was to promote public safety and remove technical barriers to trade within Europe, replacing national standards and technical approvals with a single set of Euro-wide specifications. They are applied to all elements of a building that have implications for health, safety or energy efficiency. It is a unique directive; however, regulations do not apply to specific products, but to their performance when incorporated into works.)
Richard Grayis sales and marketing executive with PIC, a U.K.-based data cable manufacturer.
