The mystery of ‘kitchen bombs’ and the science of consumer safety

By Sumudu Chamara

“During the past few weeks, we struggled in queues and exposed ourselves to Covid-19 just to get a cylinder of gas, and now, we have to live in fear because we don’t know when that cylinder will cause an explosion.”

These were the words of a liquid petroleum (LPG) consumer, who expressed fear of LPG-related explosions and fires that are becoming worryingly more common in Sri Lanka than before. To add to the plight of the people affected by the skyrocketing cost of living and the Covid-19 pandemic, Sri Lanka now has an issue about the safety and safe use of LPG cylinders.

Explosions and debates

During the past few months, a string of explosions, said to have been caused by gas leaked from LP gas cylinders meant to be used for domestic purposes, were reported from several areas of the country, including Colombo 7, Weligama, Homagama, Ratnapura, Pannipitiya, and Nikaweratiya. Another two such incidents were reported from the Jaffna and Puttalam areas on 28 November, which were the latest of these incidents. However, most of these incidents were reported this month.

While a change in the composition of LPG was mainly blamed for these explosions, LPG providers, i.e. Litro Gas Lanka Ltd. (State) and Laugfs Gas PLC (private), have denied these allegations, saying that they have always maintained the composition of LPG in accordance with the locally and internationally recognised standards, which do not allow changes that may pose a threat to the consumers. They further claimed that the current composition had been determined taking into account Sri Lanka’s weather, among other factors.

The Sri Lanka Standards (SLS) certificate issued for LPG cylinders is SLS 712.

However, the matter of composition emerged several months ago, when then Consumer Affairs Authority (CAA) Executive Director Thushan Gunawardena raised concerns over the composition of LPG that is distributed for domestic consumption.

Speaking during a television programme, he claimed: “There is a SLS standard for LPG cylinders. However, the standard is only for the cylinder’s quality, not for the LPG composition contained within it. The gas companies can fill them with anything and sell. So far, the composition of LPG was 20% propane and 80% butane. What actually happened through the introduction of the 18-litre LPG cylinder was making the propane and butane percentage 50% each. Propane is an industrial gas, and not a domestic gas. Other countries don’t have the same 50% each composition.”

Meanwhile, Government Analyst’s Department Senior Assistant Analyst Roshan Fernando explained to the media that even though inspections were carried out at the places where LPG-related explosions were reported, these inspections did not show that any LPG cylinders had exploded.

He added that what had happened, in fact, was that gas had leaked to the normal atmosphere, thereby mixing with other gases present in the atmosphere, which had then resulted in explosions. He added that this could happen especially through the presence of an electric short or spark, and that paying attention to the electric circuits of houses, therefore, is extremely important. In this regard, Fernando further noted that in certain places that were inspected, they could see electric wires and domestic wiring circuits that had not been installed properly. “Since such circuits could create electric shorts or sparks, the likelihood of such accidents (explosions) taking place due to old refrigerators is high,” he emphasised.

Quality of appliances

As the matter became a national-level topic, the discourse on LPG-related explosions expanded, and several parties expressed different opinions about the matter. They blamed the inferior quality of gas cylinders and also other appliances such as regulators, valves, and hoses, which are used to obtain gas from the cylinder.

Professionals’ National Front Secretary Kapila Renuka Perera, an engineer by profession, stressed that therefore, it is of extreme importance that people be vigilant about the quality of not only LPG, but also the quality and usage of appliances they use in domestic environments.

Litro Gas Lanka Chemical Reaction Engineer and Health Safety and Environment Director Jayantha Basnayake, speaking to the media last week, claimed that the LPG cylinders that are currently in use can handle six times the current, normal pressure, and that the cylinders are unlikely to explode due to a change in pressure.

Moreover, speaking to the media, Laugfs Holdings Chairman W.K.H. Wegapitiya also denied allegations that the composition of LPG has been changed, while claiming that gas cylinders have been manufactured in accordance with the international standards.

Meanwhile, State Minister of Co-operative Services, Marketing Development, and Consumer Protection Lasantha Alagiyawanna last week said that steps have been taken to look into the matter, including the widespread allegation pertaining to the change in the quality and composition of LPG. Even though the report of this probe was scheduled to be presented to Parliament yesterday (29), at the time of writing this article, the State Minister had not presented it, and he was unreachable to obtain more information about the status or results of the probe.

Detection and precautions

Despite the disputes about the cause/s of these explosions, one fact most of the people who commented on the matter shared was that gas cylinders themselves did not explode in the said cases, even though they are referred to as explosions of cylinders, and that what has actually happened in almost all cases reported so far was gas leakages, in turn leading to an explosion or a fire, mostly in the presence of other risk factors such as electric sparks and highly inflammable material in the immediate surroundings.

According to scientists, in addition to gas leaks, a number of reasons can cause LPG-related explosions or fires, and the most common reason where cylinders are involved is improperly installed regulators and hoses. To prevent that, regularly checking whether those parts have been installed properly and are functioning as well as using high-quality appliances are recommended.

Regardless of the reason/s behind the explosions, it is crucial that those who use LPG take precautionary measures to prevent or at least minimise the damage caused by such incidents.

Detection of a gas leak is the first step to taking any measure to prevent explosions, and there are several simple ways it can be done in a domestic environment.

One of the easiest ways of carrying out such a test is applying soap foam around the opening of the LPG cylinder, covering the regulator, valve, and the end of the hose that is attached to the cylinder. If a formation of bubbles is observed, it can be considered as a sign of a gas leak, according to internationally accepted practices.

Even though detecting the smell of LPG while the cylinder is connected to the regulator and hose is also a common sign of a gas leak, it is not a 100% reliable method to find out whether there is a gas leak, as it depends on other factors such as the ability of a person to smell and the presence of other odours in the immediate surrounding area. In addition, hearing a hissing sound from near the opening of the LPG cylinder could also be a sign of a gas leak. Even though it is also not a 100% reliable method, it is known as a common sign of a gas leak.

Even though such observations cannot be considered 100% reliable methods and call for a more methodical inspection to determine whether there is actually a gas leak, there is a high likelihood of such an observation being a result of a gas leak, and such observations, especially when both a LPG smell and a hissing sound are observed at the same time, should not therefore be ignored.

In addition, a device known as the gas leak alarm or detector is available in the local market, including in several online stores, and they too can help conduct an inspection in a domestic environment without any specialised knowledge or experience, with this method being identified as a reliable device in international markets as well.

In the event signs of a gas leak are identified, people can take several immediate measures to prevent or minimise the likelihood of a fire or an explosion.

Among them are immediately stopping the use of LPG (if LPG was being used when the leak was identified), i.e. switching off the gas cooker, and removing the cylinder from the cooker and putting the safety clip (attached to the regulator or valve) back on. In addition, if there are any inflammable materials in the immediate surrounding area, such materials should be removed immediately. Also, if there are any fires, putting out that fire should receive priority.

While removing the cylinder from the house could also be a precaution, house dwellers must do so only if they are certain that their safety would not be jeopardised in attempting to do so. It could be risky when the safety clip or the regulator does not stop the gas leak or when gas has been leaking for more than a few minutes, and in such circumstances, distancing themselves from the cylinder and contacting the authorities is recommended.

Whether it is possible to remove the cylinder or stop the leak, opening windows and doors of the part of the house where the LPG cylinder is kept, in order to increase ventilation, is highly recommended. However, people must be vigilant about whether there are any inflammable materials or fires near the doors or windows that are being opened, and get rid of such before opening them. Also, refraining from using any device that could create a spark such as a light switch within the room where the leak is detected is recommended.

In the event of an explosion or a fire caused by or has occurred when there is a gas leak, moving as far away as possible from the place of such incident and contacting the relevant authorities including the Fire Services Department are recommended.

As a long-term measure, keeping the LPG cylinder away from the gas cooker (using a longer hose) – preferably at a place that does not get exposed to high temperatures or direct sunlight for a prolonged period of time – or outside the house has been recommended by, and is being practised in, a number of other countries. However, being vigilant about any damages to the hose, especially those caused by rats biting the hose, and covering the hose are also necessary.

In fact, this measure is becoming popular in Sri Lanka. Social media posts during the past few weeks showed that certain LPG consumers have started to keep their LPG cylinders outside the house and kitchen while using a longer hose to obtain gas, as a measure to avoid a fire or an explosion inside the house. But it should be emphasised here that the cylinders should not be exposed to the elements. Also, some companies had advertised lockable metal frames and cages for those who are willing to adopt the said measure to keep their LPG cylinders outside the house and away from house dwellers, while also giving the opportunity to keep LPG cylinders safe from burglars. However, this measure can also pose a certain danger as keeping it outside the house (without covering it) can expose the LPG filled cylinder to higher temperatures, which can, in turn, increase pressure inside the cylinder and result in an accident.

Another international best practice is replacing the regulator and the hose more frequently or as recommended by the manufacturer. However, attention should be paid to selecting high-quality regulators, those that can handle high pressure as well as the high temperature prevalent in Sri Lanka, and other appliances.

While the authorities are trying to find out the reasons for these explosions, identifying and finding solutions take time, and LPG consumers should, therefore, pay attention to adopting immediate, improvised measures to ensure that the cylinders of LPG they have been/are using are maintained properly and safely. Also, attitudinal changes are necessary to encourage the people to check their LPG supply more regularly and to make it a normal practice, and thereby not wait until a disaster happens.