PETALING JAYA: There are two fundamental hazards in industrial gases – the gas itself and the high pressure under which it is stored in cylinders.
If mishandled or fitted with substandard parts, industrial gas cylinders can turn into “deadly missiles” that can lead to disaster, according to veteran chemist Datuk Dr Omar Shawkataly (pic).
The retired Universiti Sains Malaysia (USM) professor of chemistry said the pressure in cylinders was typically between 1,500psi and 2,000psi or higher.
That is way higher than the 200psi of a domestic cooking gas tank.
Dr Omar said mishaps were often caused by fittings, namely the valves, regulators and hoses.
“The cylinders have thick walls to withstand the high pressure within, but the problem often lies in the fittings. If it is of poor quality and breaks off, the high pressure will send the weighty cylinder rocketing away like a missile.
“This can be extremely dangerous. This is why gas cylinders must be secured well against a strong wall with thick solid steel chains and not raffia string.
“The same should be done when they are transported,” said Dr Omar who has researched compressed gases for over 40 years and specialises in carbonyl chemistry.
He said even the wrong use of material in manufacturing valves can be a hazard. Valves made from copper or copper alloys, if used for tanks containing acetylene gas, could result in an explosion as the gas reacts adversely to the metal. He said proper installation of valves and hoses are also equally important.
The chartered chemist said that while leaks from flammable gas may cause fires or explosions, non-flammable gases can prove to be equally deadly, especially when it involves cryogenic gases.
Dr Omar said these gases are are extremely cold, at around -115ºC, and can expand to very high volumes when exposed to air.Pure cryogenic oxygen can cause asphyxiation if released in enclosures.
“A litre of cryogenic liquid can expand to over 200 times more in open air. If there is a leak of liquid oxygen, it can choke us because the air we breathe contains 21% oxygen and 78% nitrogen.
“If oxygen levels go way beyond this, it can displace nitrogen. If nitrogen levels go up or down, we die,” said Dr Omar who was with the National Council for Occupational Safety and Health as an observer for 15 years.
While there are comprehensive laws governing industrial gas in Malaysia, there is inadequate training on safety for workers.
“More training should be held for the workers around an environment surrounded with high pressure gases. Various types of valves may not be interchangeable with the use of different gases.
“Refilling cylinders with gases they were not built for or accidentally mixing two kinds of gases can also be disastrous. Some ‘empty’ cylinders could have residual gas trapped in them,” said Dr Omar, who felt industrial gas parts and fittings must be made to meet Sirim standards.
