Cooking with gas

Many serious cooks swear by gas hobs. They’re reliable, incredibly controllable, efficient, cost-efficient and – best of all – they work during load shedding, as long as you have a box of matches nearby. And you can’t beat the aesthetics of a gleaming stainless steel gas hob. But how safe is cooking with gas?

But how safe is gas?

There are risks associated with gas but, if properly installed and properly used, they are minimal. The obvious risks are inhalation, which can lead to death; fire, which can lead to death; and explosions, which can lead to death. These are all pretty serious, and we know about them, so there is a plethora of regulations to ensure that stoves and any other gas appliances are installed safely.

But, somewhat disconcertingly, a recent study in California has shown that – even when used 100% in accordance with the regulations – gas appliances emit toxic fumes. Now these are clearly not in the same league as the indoor pollution associated with indoor cooking on open wood fires or paraffin stoves, but the research indicated that cooking with gas for about an hour indoors can increase levels of carbon monoxide (CO) and nitrogen dioxide (NO₂) to unacceptable levels. The results showed that people (especially children) living in houses that used gas were more susceptible to asthma and other respiratory illnesses. The good news is that the study was conducted in the USA, which means that it may or may not be applicable here.

There is gas, and then there is gas

When we, in South Africa, think of cooking with gas, we usually think of liquid petroleum gas (LPG), which is that stuff that is delivered on the back of trucks in big containers, or that lurks on the outside of caravans or overland vehicles in pretty blue cylinders. LPG, which is produced in a refinery from – usually – crude oil, consists of either propane or butane. It is heavier than air, so it tends to sink if there is a leak, and it is almost exclusively sold in containers.

Coal gas, also called town gas, was the original piped gas that lit up industrial revolution-era cities all over the world from fantastically convoluted gas works on what was then the urban periphery, but soon became pretty central. Until the Johannesburg gas works were closed down in 1992, and the Woodstock Gas Works in Cape Town in 1996, people living in some of the older, more central parts of the city could still get piped gas. Coal gas is lighter than air.

Natural gas, which is mined as a gas, is mostly methane. It is lighter than air, and can also be transported long distances through pipelines. This is similar in chemical make-up to coal gas, and it is this gas that was the subject of the research in the USA.

And, of course, there is biogas, which can be manufactured on either a small scale or a large scale. Many off-grid houses, for example, divert their sewerage and other waste into a biodigester, which produces methane (and clean water). This route is not for everyone but it does have many great advantages, not least of which is that it burns methane, which is the ultimate greenhouse gas, to produce CO₂, which is also a greenhouse gas, but 23 times less damaging than methane.

Decisions, decisions, decisions

Yes, there are risks associated with cooking with gas, but they are on about the same scale as the risk of your car catching alight because it is fuelled by an inflammable substance, and the advantages generally outweigh the disadvantages.

Whether you are building from scratch, installing new equipment, or thinking of buying – either a house or a stove – just do your homework. It’s all about knowing the risks so that you can control them.

Most importantly, know what kind of gas you are dealing with, and make sure that your appliances are set up correctly for it. You also need to ensure that you have adequate and appropriate ventilation and, if you are using bottled LPG, make sure it is stored correctly. Obviously, ensure that any installation is done by qualified people – this is not a good place to practise your DIY skills. These all deal with the risks of fire and inhalation – which are small risks, but with very serious consequences. The question of air quality due to burning gas is somewhat less established but – to play it safe – always use an extractor when cooking with gas.

Bottom line – the risks are minimal if you comply with all the recommended safety regulations, and gas appliances undoubtedly enhance your home and/or your estate. But the results of the US study do point out that indoor air quality is as important – if not more important – than outdoor air quality.