At 70°C, it takes less than one second of exposure for a full thickness skin scald in healthy adults and much less time for small children and the elderly whose skin is more sensitive. That the very young and very old are less mobile means they are less able to react to a hot water hazard which increases their chances of a longer exposure and a more severe scald. The statistics for hot water scalds make grim reading. One New Zealand child a year dies from hot water scalds; toddlers are most at risk. Two children will be hospitalised every week in New Zealand and their average stay is eleven days. One child will be treated in an emergency department every day in this country.

Children are not the only ones at risk. Between 1978 and 1987, 21 women over the age of 65 died while bathing and showering. Of the total 29 thermal deaths from contact with hot liquids amongst elderly women during this period, 13 were under institutional care and 13 were in private homes (the location of the other three was unknown). These statistics do not illuminate the reality of ruined lives - the pain of scarring; the isolation of rejection; the guilt of care givers and the broken relationships that do not survive the trauma - all the human costs to these tragic events that can not be quantified. These statistics are appalling. They are appalling because all of these injuries were foreseeable and were therefore preventable. They need not have happened. They are appalling for another reason. In New Zealand, only 1.8% of the health budget is applied to public health services and, within this 1.8%, hot water scalds are not a health priority. We simply do not devote sufficient resources to prevention.

There are other reasons of course. No one Government agency will take ownership of the problem because a large part of the problem belongs to someone else. The problem belongs to three sectors - health, energy and the building sector who each need to make a long term commitment to work together to pool their expertise and resources to a single vision for the public good.There has to be the realisation from each of them that there are no simple solutions. There are three sets of problems with hot water systems - safety problems, energy efficiency problems and effectiveness problems. The intractability of fixing hot water systems arises because essentially every hot water installation is unique. The uniqueness arises from the large number of components which are interconnected to form the system, the external factors that can impact on performance and from the people who use the hot water (when, how much and what for).

People expect nothing less than a hot water system that works. What this means in practice is that the safety issues, effectiveness issues and the efficiency issues must be treated in tandem and individual solutions derived for individual installations. Otherwise, single issue solutions will be promoted which will seldom work. That a straightforward action such as turning down a thermostat is much more complex than it initially seems should not detract from the fact that it is a worthwhile aim. From a safety perspective, the lower the temperature, the less likelihood of scalding. From an energy perspective, it has been estimated that reducing the temperature by 10°C nationally could result in savings of 250GWh and a deferred capital investment, by the electricity industry, of $120 million. However, the realities of turning down thermostats must be considered and addressed:

• Many dwellings have hot water cylinders that are under-sized and under-powered for family needs. Reducing the temperature of storage reduces the amount of useable hot water, which will compromise the performance of hot water systems that were inadequate in the first place.
• A system, which performs adequately on a reduced thermal capacity in summer, may not be able to cope in winter when the incoming cold water temperature may be as much as 15°C lower than that in summer. Colder winter water means that more hot water is required in a useable mix of hot and cold water which makes it more likely a family will run out.
• Power companies ripple off the electricity supply to hot water cylinders (particularly in winter when the demand for electricity is high). Ripple control means that hot water systems typically get lower cost electricity for heating water for 17 hours per day rather than for 24 hours as with other types of appliances. If the temperature of storage is reduced in summer when a power company is not controlling the hot water, then when ripple control begins, the thermal performance will be compromised by the restricted winter supply of electricity and become unacceptable.
• Low pressure hot water systems, which predominate in New Zealand, have notoriously poor hot water pressures together with very high cold water (mains) pressures. Many families compensate for these poor hot water pressures by using very hot water temperatures to get a comfortable shower. The proportions of hot and cold water determine the final shower pressure. Since the cold water is at a higher pressure than the hot water, the more cold water there is in the mix, the higher the final pressure. If the hot water is very hot, then more cold water is needed to get to the desired temperature and the final pressure will be relatively high. Turn down the hot water temperature for safety and the shower more than likely will not work.
• Thermostats are not precise instruments nor are many very accurate, particularly the older models installed in the majority of existing dwellings which often do not control the temperature of the water accurately. This means that the great majority of New Zealand families can not rely on their thermostat setting to specify the actual temperature of their hot water.

It is for reasons such as these that promotional campaigns to raise the awareness of families to the dangers of hot water simply will not work without all the many elements of the market delivery mechanisms for safe, effective and efficient hot water already being in place. The good news is that New Zealand has excellent legislation to protect the health and safety of building occupants. This legislation, the New Zealand Building Act and the New Zealand Building Code applies to all new building work, whether in new or to existing buildings. For new buildings and all new building work, water must be delivered to the sanitary outlets at a temperature that avoids the likelihood of scalding - currently defined as 55°C - except for schools, day-care centres and old people’s homes where it is 45°C. Proposed revisions to the code will also include psychiatric institutions, hospitals and facilities that care for the disabled amongst the exceptions.

Buildings that do not have safe water temperatures may be deemed to be dangerous. The Building Act contains provisions for territorial authorities to initiate remedial action if the building is considered to be dangerous or insanitary. A dangerous building is one that is likely to cause injury or death to any persons using it. The supply of scalding water would be sufficient to categorise a building as dangerous. In a practical sense, territorial authorities should, at the very least, monitor facilities that have a duty of care for the young, the elderly, the infirm and for people with physical or intellectual disabilities. Housing New Zealand, as an agent for the crown, should also be called upon to ensure that their premises are safe.

The challenge for us all is where to go from here. Who will pick up this challenge?. The process is a long term one. Unless there is a concerted effort to a common vision encompassing all the stakeholders from the health, energy and building sectors, hot water problems will take as long to fix (50 years) as the time it took to create them in the hot water systems in use in New Zealand today. Unless action begins now, our children will inherit the same sets of problems within existing buildings as we are experiencing now and we will continue to scald and maim our young and our elderly - an outcome that must be abhorrent to us all.

The authors can be contacted at 34 Archmillen Avenue, Pakuranga, Auckland. Telephone/Facsimile 09 576 4346; Email warrenh@ihug.co.nz.

BARRIERS TO SAFE HOT WATER:
PLUMBER AWARENESS