Dr Hector Perera         London

The gas and electricity are not supplied for free, one has to pay for them in one way or the other. Fortunately oxygen needed to burn the cooking gas or methane is getting for free from the atmosphere. Simply because methane is there it does not burn unless it is reacted with atmospheric oxygen.

CH4    +    2O₂     —-à     CO₂     +      2H₂O

The above reaction is the complete combustion of methane with oxygen. For every molecule of methane, one molecule of carbon dioxide is produced but if there was not enough oxygen then, methane burns to give carbon monoxide.

2CH₄    +     3O₂    —-à     2CO     +     4H₂O

This is all chemistry but let me put into simple form where anyone can follow. When you light the cooker if there was a blue flame then we say it is a complete combustion reaction and it should be the way to use a cooker. If you find yellow flame instead of the blue flame then you know for certain incomplete reaction takes place. It may be due to the faulty adjustments of the cooker or most often due to lack of oxygen supply. Some people hardly clean the cooker, just cook. It may be due to some dirt fallen over the burner then it gives this yellow flame. Why not check the cooker surface, then you will see how dirty it is that means there must be some dirt on the burner as well. Most of the cooker surfaces have oily sticky surface and pieces of food fallen all over. Then the burner surface or the gas inlet as well must be covered with dirt such as food particles and oils fallen over so that it gives this yellow flame. This is a feeding grounds for cockroaches and mice. Carbon monoxide is very dangerous and poisonous to breath. If there was a gas leak then we can detect by the smell but carbon monoxide has no smell that means it cannot be detected by smell or even cannot be seen.

Carbon monoxide is poisonous

It is recorded that every year people die from carbon monoxide poisoning. Two main places that carbon monoxide is given out are due to faulty gas boilers and faulty cookers. It was not long ago it was reported a whole family suffered from carbon monoxide poisoning from the faulty air conditioner in their holiday apartment. The two young children couldn’t be saved and the parents survived but they really suffered. Carbon monoxide acts as a poison by combining with the haemoglobin in the blood. In normal condition oxygen from the air combines with the haemoglobin and transport oxygen around the body.

I have seen some people cook in gas cookers but the flames were not properly adjusted and gave out nothing but yellow flames due to incomplete combustion of methane. Some people cook but they hardly open the windows or the kitchen door for fresh air then the gas produced might contain this poisonous carbon monoxide.

If I recall my mind back to Sri Lanka cooking in the good olden days, I think the kitchens were full of carbon monoxide gas. Burning wood is a very complex chemical process, and there isn’t one chemical reaction occurring. Wood consists of a huge mixture of chemical compounds: depending on the type of wood, the temperature, moisture content, amount of oxygen, and many other things many different chemical reactions take place.

But wood is mostly made up of cellulose, which is a compound of carbon hydrogen and oxygen. When this is burned, the overall chemical reaction is to combine oxygen from the atmosphere with these to form carbon dioxide and water. But in between there may be many intermediate products: under heating many liquid and gaseous compounds leave the wood and are burned with oxygen (these also contain mostly carbon hydrogen and oxygen), and leave behind mostly carbon (charcoal), this carbon burns with oxygen to produce carbon dioxide and carbon monoxide (depending how much oxygen is available). It is a very complex process and no one chemical reaction can apply!

 Quick shopping in Sri Lanka

A few times we stopped to buy Sri Lankans favourite food called, hoppers from roadside places. They not only make hoppers but other things such as Pittu” and roti as well. In one of the places, I saw this man behind the cooker was making hoppers quite quickly but when I looked at the flame of the gas burner, I realised it is not properly adjusted, it gave a yellow flame. In many ways it’s not right and not healthy to use such a gas cooker. Who knows some flour fallen over the gas burner then it gives yellow flame. He had to inhale the poisonous gas while he is cooking. I didn’t tell him how to adjust the flame because I never knew if he would admit. Not only this place if you look at the other takeaway places or people who make hoppers or in some takeaway places, the gas flames are not properly adjusted or give yellow flames. Not only that some people purposely set fire to cooking aroma while cooking. Do they realise that they are inhaling that poisonous mixture of gases?  One other question is would it give a better flavour? That I observed in Sri Lanka.

Then recently we visited an area called Wembley in England where there is a famous football stadium. The high street is full of Asian shops, takeaways, restaurants and Asian groceries. We saw this restaurant with some of our local delicacies such as Sri Lanka style sweets and other kinds of food. A lady served us and she appears to be a Sri Lankan then I found out that she is from East of Sri Lanka. The things such as different types of wade” and sweets brought back the memories of home. In the background they were cooking something and the flames were in reducing state or in yellow flames. I didn’t want to let them know because I was not sure if they would like the idea. So not only in Sri Lanka but also in some places in England as well, they cook in reducing yellow flames. That is a totally wastage of energy.

Here are plenty of good reasons why you should make an effort to cut down on your energy usage at home. Not only does using less gas and electricity help to reduce the level of harmful CO₂ produced, but it also helps you cut down the costs of your utility bills. I am sure you heard of global warming due to carbon dioxide. We may be able reduce a fraction of this global warming if we are careful in cooking. Your comments are welcomed perera6@hotmail.co.uk