Page 8 - OHS, November/December 2022

IH: GAS DETECTION
The Evolution of Gas Detection
Enhanced solutions take detection of hazardous, toxic gas to the next level.
BY ROBERT KESTER
You may not always be able to smell it, taste it or discern its presence, but toxic and flammable gases can present significant industrial hazards. New technologies are improving gas-detection capabilities, helping safety managers ensure employee health and well-being.
Although it is typically viewed as a cultural relic from the days of the first Industrial Revolution, the practice of carrying canaries into mines to detect carbon monoxide continued in some countries into the 1990s. First conceived in the 19th century by scientist John Haldane following a series of studies into the cause of miner deaths, Haldane determined that the portability and anatomy of canaries made them an ideal early indicator of airborne poisons.
The canaries were the miners’ only gas detector until 1986, when an “electronic nose”—a detector with a digital reading— largely replaced the birds, ultimately leading to their redundancy in 1996. This was the first of several considerable, much-needed improvements made to gas detection technologies—improvements that continue to this day, as gas detection becomes integrated into wider environmental monitoring.
Technology for communicating gas hazards has improved significantly, with real-time monitoring that ensures speed and accuracy. In addition, the sensor networks that measure environmental factors are becoming connected to one another, which helps safety professionals identify problems sooner and act faster.
This enhanced responsiveness is invaluable, as industrial processes increasingly involve the use and manufacture of highly dangerous substances, particularly toxic and combustible gases. Some industries generate gas hazards or rely on chemistry that itself poses a danger, such as the processes involved in electric power management, water treatment and paper production
Identifying dangers early and accurately is of paramount importance
because gas hazards can be invisible and hard to identify. Some gas leaks can go unrecognized until the victims experience symptoms of distress—which may be too late.
To help safety managers understand the options, here’s an overview of gas detection options with a few tips on how to approach assessing the right choice for business needs.
The Three Dangers of Gas
Gas hazards generally are separated into three categories: flammable (fire or explosion risks, such as methane or propane), toxic (poisoning risks, such as carbon monoxide or chlorine) and asphyxiant (suffocation risks, primarily oxygen deficiency, including situations where oxygen is consumed or displaced by another gas).
The distinctions are important even thoughthecategorieshavesomeoverlap. Many gases are both combustible and toxic, for instance. However, the hazards and regulations involved are different, as are the sensor types required to identify them.
While all hazardous gases are dangerous, some are more inconspicuous than others. Even low concentrations of some gasses can affect workers who are
exposed. It’s not always about inhalation, either; poisonous gases are sometimes absorbed through the skin. Because of the adverse effects from long-term exposure to gas additives, it is important to measure both the concentration of gas and the total exposure time.
Toxic gases are present in nearly every industry, but some gases present unique challenges to specific industries. In the semiconductor industry, for example, gases including phosphine and arsine are especially flammable and toxic. Etching and cleaning industries face similar issues with ammonia.
Obviously, gas hazards are serious, pervasive and insidious. While technology has always stepped in to improve detection, the industrial reliance on often-dangerous substances means we have to look for even more safety-measure improvements.
Today’sGasDetectionTools
An optimal instrument system monitors both short- and long-term exposure levels, as well as instantaneous gas levels. In every system, the detection process raises an alert. This spurs staff to respond appropriately to comply with relevant industrial regulations and safety requirements. With so many harmful gases to identify and measure, it’s no
8 Occupational Health & Safety | NOVEMBER/DECEMBER 2022
www.ohsonline.com
chalermphon_tiam/Shutterstock.com