Page 34 - OHS, January/February 2021

IH: CHEMICAL SAFETY
Chemical Plants. A variety of flammable and toxic gases are used during the chemical manufacturing process or generated as byproducts. Typical environments where gases may be present include raw material storage, compressor stations, process areas, loading/unloading areas, laboratories and pump rows. Hydrocarbons are the most obvious example of flammable gases in chemical plants, while toxic gases include hydrogen sulfide, hydrogen fluoride and ammonia.
Ethylene, Butadiene and Vinyl Chloride Production. This is a common chemical manufacturing application that may produce hazardous gases, particularly during the refinement process. Typical situations in which workers may be at risk range from hydrocarbon and non-catalytic cracking processes to bulk storage and confined space entry. The most common flammable gases are hydrocarbons. Typical toxic gases include hydrogen sulfide, hydrogen fluoride and carbon monoxide.
IPA Production. As mentioned, companies in the chemical industry have had to step up their production of IPA in recent months. If inhaled, this chemical compound can cause drowsiness, dizziness and headaches.7 Studies have also shown that IPA contains carcinogenic properties, meaning that prolonged exposure may lead to an increased chance of cancer.8
Typical applications in which workers may be exposed to IPA include:
■ Inorganic synthesis of various isopropyl derivates
■ Feedstock for the manufacture of cleaning and degreasing agents
■ Extraction and purification of alkaloids, perfumes, resins and waxes
■ Manufacture of adhesives
■ Manufacture of acetone and surface coatings, thinners, cosmetics and pharmaceuticals
Volatile Organic Compounds (VOC) are the typical gases released during these processes. They can be flammable and toxic at the same time.
Pharmaceutical Process. Pharmaceutical manufacturing is another sector that has witnessed sustained growth in recent months. There are many situations in which toxic and flammable gases may pose a threat to workers, including:
■ Bulk storage and preparation of areas for production
■ Exhaust monitoring
■ Monitoring chemical compounding and synthesis processes
■ Monitoring cleaning agents used in the sterilization process
Key Regulations to Designed to Protect
Several standards and regulations exist to prevent exposure to hazardous gases. Keeping up to date with this legislation is key to providing workers with the most adequate protection.
In the United States, OSHA’s Hazard Communication Standard (HCS) mandates that information about chemical and toxic substances and associated protective measures must be disseminated to workers.9 OSHA also sets enforceable permissible exposure limits (PELs) on the airborne concentrations of hazardous chemicals in the air.10
As our knowledge of hazardous gases and their effects on human health continue to grow, we may expect new, more stringent regulations in the future. The European Commission recently proposed introducing new legislation to limit worker
As our knowledge of hazardous gases and their effects on human health continue to grow, we may expect new, more stringent regulations in the future.
exposure to cancerogenic chemicals.11
How to Select Gas Detectors Effectively
Gas detection plays a major role in alerting users to the presence of toxic and flammable gases, and there are different technologies to choose from. Any selection process should always start with a thorough risk assessment. This is key to mapping out all the hazardous gases that may be present in different areas of a facility.
Gas detectors can either be fixed or portable and, under most circumstances, a combination of the two technologies may be the best choice. Fixed gas detection is often the first line of defence for workers and plant safety. It provides workers with invaluable insight into the status of the plant and alerts them of any gas leaks. Portable detectors offer an extra layer of protection. They are especially valuable in blind spots that may be out of the reach of fixed detection, one example being confined spaces.
Fixed gas detectors. There are many different types of fixed gas detectors, so the selection process can be tricky. Opting for a flexible and scalable solution may be a good choice for chemical plants with multiple gas hazards that may change over time. For example, universal transmitters for the detection of toxic and combustible gases are generally compatible with the widest range of gas sensors. They are also modular, meaning they can be expanded and upgraded over time.
Infrared point hydrocarbon gas detectors are the go-to solution for potentially explosive atmospheres. They offer fast response, low maintenance and long service life.
If VOCs are the main threat, then fast-response fixed photoionization detectors (PID) are the best option. Some of the latest solutions on the market offer enhanced sensitivity, reduced maintenance costs and accurate readings.
Portable gas detectors. There is no one-size-fits-all portable detection solution, so making the right choice often depends on the application and the associated gas hazards. For example, some of the latest five-gas detectors are designed specifically for sampling and monitoring confined spaces before and after entry. They offer advanced sensor technology, great visibility on gas readings, comfort and wireless connectivity.
Multiple gas threats across different locations may require flexible solutions with up to six gas sensors combined with wireless portability. Some of the latest portable devices are highly versatile and customizable, providing real-time access to instrument readings and alarm status from any location. In some
30 Occupational Health & Safety | JANUARY/FEBRUARY 2021
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