Gas safety in schools

When products used by the building occupier are specified at the design stage it is done under the proviso that they will be manufactured to the highest possible safety standards and comply with the latest legislation outlined by the respective governing body. This responsibility quite rightly lies with the product manufacturers.

Arguably the most stringent of these legislations are the gas regulations produced by the Institute of Gas Engineers & Managers (IGEM). Particularly as they cover the management of highly flammable substances that will be potentially used by pupils as young as 11 in schools. For this reason, gas safety and isolation within educational establishments has always been governed by additional legislation which goes much further than the requirements set for other premises.

Local isolation

The former British Gas publication IM25 released in 1989 set the benchmark for the more recent IGEM/UP/11. In July 2010, Edition 2 aimed to clamp down on the many grey areas of its predecessor through the addition of key safety instructions; although as is always the case, some requirements are still open to debate. This legislation provided more guidance on what is considered to be the most crucial part of an educational building’s entire gas network – user controlled emergency isolation. All of the key plant areas are designed to run with very little maintenance and interruption whereas the local isolation in each room can be controlled by someone who may not necessarily be aware of the potential risks associated with their actions.

Within the revised legislation, details are given on what should be incorporated into a local isolation system, specifically automatic isolation. Where automatic isolation is required for the means of interlocking, a pipework integrity system (gas proving system) must be installed. Such a system, comprised of solenoid valves, pressure switches and timers, performs an automatic downstream check to ensure the closure of all outlets, such as gas taps or burners, on start-up.

The very presence of this system takes the responsibility away from the teacher and provides a safer teaching environment as there is no allowance for oversight on the user’s behalf, such as a half open gas tap at the back of the room.

The only downside to such a system is that the proving cycle is only completed upon start-up. This means that once the gas has been enabled, there is nothing to stop a tap being opened without being lit. The key function of the system after this point is to monitor for low incoming gas pressure and check for fault signals provided by connected items such as emergency stop buttons, fire alarms and ventilation interlocks. Unfortunately this will always be the case because when it is based on pressure monitoring alone, there is no way to differentiate between burnt and un-burnt gas. However, monitoring of this can be achieved by interfacing remote gas sensors with the gas proving system.

Gas Sensors already play a key safety role in any plant room. Boiler houses usually go unmonitored for long periods of time and even though the risk of modern day boilers producing Carbon Monoxide as a result of poor performance is low, it is still a risk. As is the build-up of un-burnt gas leaked from pipework that may deteriorate over time. On this basis, Methane/LPG and CO detection should be considered in all plant rooms, especially where they are an integral part of the main building infrastructure due to the associated risks.

The release of Building Bulletin 101 in 2006 saw Carbon Dioxide monitoring in schools become a key requirement when designing ventilation control systems. Studies have shown that once the levels rise above 1000ppm, the ability of the pupils to concentrate can be affected, so every effort has been made to reduce the Carbon Dioxide levels with the aim of achieving  the ideal working and teaching  environment. Not only this, but the constant battle to increase energy efficiency and reduce running costs have resulted in demand control ventilation becoming the industry standard.

By closely monitoring CO2 levels, building managers can calculate and control the ventilation system requirements to ensure it is only used when needed, which in turn drives greater energy efficiency.

Many of the key guidelines in Building Bulletin 101 regarding ventilation requirements in such areas as laboratories have been weaved into IGEM/UP/11 Edition 2. Unfortunately, due to perhaps the lack of publicity when releasing a document of this nature, many of the changes have gone unnoticed – a good example of which is the requirement for the ventilation to be interlocked with the gas supply in all teaching areas. This ensures there is sufficient fresh air and removes any toxic gases which are produced as part of the combustion process. It also provides a means of limiting CO2 levels and counteracts the build-up of additional CO2 produced by combustion. For this reason, it is now suggested that where there is no means to interlock the ventilation, a CO2 monitor should be interlocked directly with the gas supply.

The ever changing legislation is designed to help improve health and safety but the constant drive to improve the environment in which we work and learn, and the recent budget cuts put an additional strain on companies to provide a cost saving. As a result we have to ask whether too many corners are still being cut and whether the welfare of the future generation is being put at risk as a result.