Gas Cooking Stove Safety

Dangers from gas cooking stoves and how to avoid them

Gas Cylinders can be dangerous

A good friend of mine had a very near miss with a gas explosion in his kitchen. He was very lucky and was left with singed eyebrow.

It was a sobering reminder of another friend who many years ago in Western Australia was nearly killed when, wearing only swimming trunks, he ran towards a burning house when a gas cylinder exploded. With over 70% (yes I did say 70%) burns he was very lucky to survive and it took a lot of pain and many years of hard work and the expertise of the legendary burns unit in Perth Hospital to save him, the result of a split second badly made decision.

Gas is important for most of us but continues to be one of the most significant dangers we live with every day of our lives.

Gas Stoves leaks

My friend has a gas stove in his kitchen, it is a design very common in Indonesia with a cupboard built into the stove to hold a gas cylinder. The gas regulator (the device that attaches to the valve on the top of the cylinder and controls the gas flow to the rubber delivery hose) was leaking. Many regulators leak but we'll come to that in a minute. The gas had built up inside the cupboard so when my friend leaned into the oven to light it the cloud of gas mixed with oxygen exploded. Fortunately for him the kitchen is well ventilated so the gas build up was not too great but still he was left seriously traumatised. This could have happened to many of us, how often it happens we don't know but we can be pretty sure that it is a little more common than many of us would like to think.

Where will a gas stove leak?

The story raises a series of issues to consider so let us go through them.

1. Gas cylinders in enclosed spaces

Having the gas cylinder inside a cupboard that is built into a gas cooker is about as sensible as giving the kiss of life to an irritated tiger. Gas regulators and cylinder valves often leak so gas cylinders should be kept in ventilated areas preferably outside the building especially if the kitchen is not ventilated. Gas water heaters should also be outside.

2. Gas Smell

In its natural state the gas that we use does not smell and so, for public safety, a smell is added (a government requirement) so people will be aware of a gas leak if it occurs. Modern liquified petroleum gas (elpiji as it is known) has a smell but it isn't very strong, well - not as strong as the old "coal" gas we used at home when I was a lad which was smellier than a flatulent skunk after a meal of boiled cabbage. Mind you it isn't a lot of use if you have no sense of smell as is the case with the subject of our story. In short we cannot put all our trust in the smell of the gas to save us.

3. Poor quality gas regulators

Regulators are a constant source of problems and are probably the weakest link in the gas safety issue. Some are very good but many are manufactured in the backstreets of nameless cities by people who should be milking cows rather than milking their hapless customers.

4. Cylinder valves

The brass valve on the top of the gas cylinder may be faulty or it may leak where it is screwed into the top of the steel cylinder. There are a lot of valves around that have been manufactured to very poor standards.

5. Rubber seals in poor condition.

In the top of the cylinder valve there is a small rubber ring, this provides a seal between the regulator and the brass cylinder valve. These easily get damaged and so are a common cause of gas leaks. They should be checked whenever the regulator is connected to a cylinder. When refilled by Pertamina the seal is checked and often replaced to make sure it is in good condition.

6. Rubber hoses

The rubber hose that carries the gas from the regulator to your appliance will deteriorate with age, particularly if exposed to sunlight. It needs to be checked regularly and replaced if damage is found.

Gas safety does and don'ts

• Never have your gas cylinder next to your stove or in an enclosed space
• Do not put your cylinder in a cupboard built into a cooking stove.
• Make sure your kitchen is well ventilated.
• Look for a good quality regulator and one with a gauge on it to tell you how much gas is in the cylinder.
• Check the condition of the regulator on a regular basis.
• Check the condition of the rubber hose for cracks or other signs of deterioration or damage.
• Before connecting a regulator always check the condition of the rubber ring seal in the brass valve on top of the gas cylinder.
• Keep some spare rubber rings at home so you can change them if necessary.
• After you attach a regulator to a gas cylinder take the time to listen to it, if you hear a slight hissing sound remove the regulator check the rubber ring and reinstall the regulator and recheck. If in doubt buy a new regulator.
• Buy your gas from a certified gas distributor.
  

Illegally Filled Gas Cylinders

There is a surprisingly common practice in Indonesia that small green 3 kgm cylinders (known locally as "bom melons" owing to their similarity to rotund fruit and the tendency of illegally manufactured ones to fulminate without warning) containing 3 kgms of subsidised gas and cost Rp20,000 each are being bought and used to fill larger blue cylinders which contain 12 kgms of gas and are then sold at the much higher non subsidised price of Rp128,000. Some time ago I passed quite a large warehouse which was full of rather furtive looking people busy emptying gas from green cylinders to blue ones. The scale of their operation and the danger to the local community was frightening.

This "decanting" of gas has several issues:

1. It is illegal and is not subject to normal safety regulations.
2. It is very dangerous for the people that use primitive home made equipment to transfer the gas.
3. It could be very dangerous for people living nearby or who are passing in the street.
4. The cylinders and their valves and seals are not properly checked each time the cylinders are refilled which may result in gas leaks.
5. You get less gas because the pressure in a refilled cylinder is lower than a legally filled cylinder.
6. You, Pertamina and the government are being cheated.

If you suspect your gas cylinder is not legally filled you can do three things. Firstly make sure you have a pressure gauge on the gas regulator so you can check the gas pressure when you first connect it to a new cylinder. You can also weigh the cylinder, a full blue cylinder should weight 26.8 kgms. If the gas has been illegally decanted you may find that both the gas pressure and the weight of the cylinder are lower than they would be on a legally filled cylinder.

To address this very common issue the government is introducing a new system in which only people who are registered as poor people will have a card which will allow them to buy subsidised gas in the small green gas cylinders. They will be allowed to buy up to 2 cylinders a week (more if they are running a warung). It is good to know that action is being taken however we can assume that ways will be found to get around this.

If you want to be sure that you are getting legally filled gas cylinders only buy your gas from an official Pertamina distributor.

Cooking Stove heat activated gas shut off valve

Most cooking stoves these days have safety features built into them to protect you.

The most important is a heat activated gas shut off valve. In the gas flame for each burner there is a heat sensor which only allows the gas to flow if it is hot. The usual way this works is that, when you turn the gas on, you have to turn the knob and push it in. Holding the knob in overrides the heat sensor, it allows the gas to flow even while the heat sensor is cold. Once the gas gets ignited and the heat sensor gets hot (only a couple of seconds) the sensor will allow the gas to continue flowing and you can release the knob. If for any reason the heat sensor goes cold (let us say a gust of wind blew the gas flame out) the flow of gas will be automatically closed off to prevent a gas leak.

When you buy a gas stove check that it has heat sensors to cut off the gas. It is also very important to check that heat sensors are installed on the oven and the griller as well as the gas rings.

Take care.