An unexpected increase in accidental domestic fire deaths revealed by the latest statistics suggests that a review of home fire safety is needed. In particular, variations in standards and regulations around the UK need to be addressed says Gerald Jones.

The latest available statistics from Communities and Local Government to 31 March 2008 show a 15% increase in deaths in accidental dwelling fires for 2007/08 – 299 deaths compared with 259 over the previous 12 months – bucking the downward trend over the last few years. These statistics suggest that more can be done to alert occupiers of dwellings early with the right type, number and location of smoke and heat alarms. But which standard should we apply? The current code of practice for domestic fire alarm systems is BS 5839-6: 2004, which is well recognised as the authoritative guidance for new and existing dwellings. Firstly, it considers ‘grades' – effectively the reliability of a system in terms of its power sources. For new and many existing dwellings, grade D is the minimum standard comprising interlinked mains alarms with backup, a requirement matched in all the national building regulation guidelines applying to new build.

The code of practice then goes on to define ‘categories', effectively the areas in which smoke and/or heat alarms are required. It is with these categories that major differences between national regulations and the code itself can be found. It points out that category LD3 – smoke alarms just in corridors – is only intended to protect circulation areas used as escape routes and "might not therefore prevent the death or serious injury of occupants in the room where the fire originates". Just over half of all domestic fire fatalities occur in the room of fire origination – in the case of bedrooms this rises to 63%. It also stresses that "the time available for evacuation of other areas once the fire is detected in the circulation area might be quite short." It is for these reasons that it recommends category LD2 for new and many existing dwellings as a minimum. This means, for instance, smoke or heat alarms in living rooms and a heat alarm in every kitchen, as well as the usual smoke alarms in circulation areas.

Conflicting regulations
This approach has been embraced in the Northern Ireland building regulations, with Technical Booklet E, where compliance with the code of practice simply meets the statutory requirements. The same approach also applies in Eire. But in stark contrast, Scotland's Domestic Technical Handbook just calls for a smoke alarm "in a circulation area which will be used as a route along which to escape… broadly… a Grade D Type LD3 system" – with no provisions for heat alarms in kitchens at all. This poor level of protection is considered completely unsuitable for new homes in the code of practice. Similarly in England and Wales, the current Building Regulations Approved Document B, Fire Safety – Volume 1, Dwellinghouses (ADB) effectively requires only category LD3 with heat alarms in some kitchens only.

The ADB requirement resulted from government-commissioned research that also considered the ability of corridor smoke alarms to awaken sleeping occupants. The ADB consultation draft included a provision that "in order to improve audibility, a smoke alarm should also be fitted in the main (largest) bedroom" – effectively as a sounder. Although omitted in the final version of ADB, this was an important proposal, recognising growing pressures for greater acoustic privacy and the resulting sound attenuation capabilities of modern partitions and internal doors. This trend for acoustic privacy is reflected in the current Part E of the building regulations, which considers sound reduction within dwellings as well as between them.

Bedroom sounders needed
Generally, doors are considered the weak link in sound reduction but caution is needed with this assumption. Modern, factory assembled doorsets now consistently provide impressive performance levels with, for example, 36 Rw dB easily achievable without special measures. This is largely due to the sealing up of door edges to minimise air – and smoke – flow. BS 5839-6 recommends achieving a sound level of 75 dB(A) at the bedhead. It also recommends more than 85 dB(A) at the doorway of each bedroom where doors exceed 20 dB ..."unless there is a sounder in the bedroom". As domestic smoke alarms usually generate 85 dB(A), neither of these levels can be achieved in most situations and a bedroom alarm or sounder is justified. Also, research has shown that young children can sleep through loud alarms while elderly people and others with hearing impairments may also not respond.

There must therefore be serious doubts that the ADB research reflects the real impact that modern doorsets have on sound reduction, and the time needed for smoke to transfer from ‘source of fire' rooms through these highly engineered assemblies to trigger corridor located smoke alarms. Unfortunately, the research report concluded that adding any more smoke or heat alarms to the minimum requirement would not "lead to any discernable further reductions in risk", signalling the probability of no change to the next ADB. Many would fundamentally disagree with this conclusion and the resulting misapplication of Category LD3, relying on assumed gaps in modern doorsets which, increasingly, are simply not there.

The risk of death and injury could be made higher by another change in the latest ADB, removing door closers from fire rated doors protecting staircase enclosures in three storey homes. Closers at least indicated to occupants the need to keep doors closed, even if they were not always completely effective.

The situation could be made even worse with removal at the end of last year of the requirement for planning permission for loft conversions. Many might assume – incorrectly – that building regulations do not apply either. And the absence of planning applications to the local authority makes it far more difficult for building control officers to become aware of the creation of three storey homes and demand essential fire protection measures including smoke alarms. To summarise, in England, Wales and Scotland pressure should continue for an upgrade of the regulations to address all these issues and remove illogical inconsistencies. But in the meantime, the safe route for responsible specifiers and clients is to simply implement BS 5839-6 as a minimum standard in both new and existing homes.

Wiring regulations
The recently published IEE 17th edition BS 7671:2008 wiring regulations will also change our approach to domestic smoke and heat alarm systems. These regulations apply across all building types – including housing – and now stipulate specific requirements for circuits of ‘safety services', defined as including "fire detection and alarm systems" and "CO detection and alarm systems." They go on to require that "circuits of safety services shall be independent of other circuits" so that they are unaffected by, for example, ‘tripping out' of lighting circuits – an increased possibility with the expanded 17th edition requirements for Residual Current Device (RCD) circuit breakers. This means that individual smoke and heat alarms can no longer be powered from lighting circuits – currently a common practice endorsed in both ADB and BS 5839-6. As the more recent 17th edition Wiring Regulations supersedes both, electrical contractors are likely to follow its requirements.

Avoiding electromagnetic interference
It should come as no surprise to find conflicting advice in this area as well. But there is another good reason for this separate circuit requirement, as devices on the lighting circuit – such as low voltage lighting transformers, compact fluorescent lamps and dimmers – are often identified as causes of electromagnetic interference (EMI) which could affect performance of smoke, heat or CO alarms. Anyway, this requirement for an independent circuit is easily and inexpensively met using ‘three core and earth' cable, where the third cable simply provides the interconnect signal to trigger all alarm sounders. This is set to become the normal method for connecting hard wired alarms, heralding a new system approach to designing fire safety measures for homes.

Whilst hard wired alarms with backup power are a requirement for new build, steps are also being taken to require them in existing homes, for example in the Housing (Scotland) Act 2006 and the Housing Health and Safety Rating System. This is particularly important for rented properties where landlords have a duty of care to their tenants and where battery failure or removal results in non-functioning alarms – sometimes with fatal consequences. So, hard wired smoke and heat alarms will become a more common feature of refurbishment and rewiring programmes and, of course, the 17th edition requirements will now apply.

Kerbing the silent killer
The Housing Health and Safety Rating System (HHSRS), which defines the ‘decent homes' standard and applies to England and Wales, is playing an increasingly important role in domestic safety. HHSRS is a risk assessment procedure introduced by the Housing Act 2004, resulting in scores that are developed to identify category 1 and 2 hazards. Local authorities must take action with category 1 hazards while category 2 hazards are discretionary. A ‘decent home' must not contain a category 1 hazard.

Fire and carbon monoxide poisoning are identified as two of the 29 hazards and smoke, heat and CO alarms installed in line with building regulations or British Standards are considered to be the ‘ideal'. Similarly, a lack of effective smoke, heat or CO alarms is cited as one of the ‘relevant matters' affecting the likelihood and harm outcome. There is therefore a strong case for the installation of smoke, heat and CO alarms to British Standards to substantially reduce a hazard. HHSRS is forming the basis for pan-agency initiatives at local level, expanding the scope of home fire safety checks carried out by fire and rescue services. In fact, we are seeing examples of fire brigades installing battery powered CO alarms as well as smoke alarms.

Carbon monoxide poisoning leads to at least 250 deaths and serious injuries every year. Vigilance and detection of carbon monoxide is even more important now, with confusion amongst the public arising from the transfer of gas installer registration from the well known CORGI to the new Gas Safe organisation this April. Despite the absence of specific legislation requiring them – at least at the moment - we are seeing a growing demand for CO alarms in both new and existing homes. As hard wired CO alarms are also ‘safety services' in the 17th edition, the simple ‘three core and earth' approach can simply be extended to CO alarms as well, on the same circuit as smoke and heat alarms.

To make the most of interconnection, some alarms have special facilities to provide expanded whole-house protection for little additional cost. For example, with Kidde Fyrnetics' Smart Interconnect facility, when a smoke or heat alarm is triggered by a fire, all the interconnected alarms – including CO alarms – activate to alert occupants of danger. When a CO alarm is triggered by carbon monoxide, all the interconnected CO alarms activate. With systems such as this, a CO alarm in the bedroom can act as the sounder for smoke/heat alarms elsewhere, addressing the audibility issue discussed earlier. For a minimal extra cost, this arrangement overcomes the inadequacies of corridor and landing-only smoke alarms in waking occupants, ensuring that sound levels required by BS 5839-6 are generated at the bed-head, as well as protecting sleeping occupants against carbon monoxide poisoning. 

Gerald Jones is Kidde Fyrnetics business manager at Kidde Safety Europe. More information is available at www.smoke-alarms.co.uk.