What can we learn from the chemical fire in Rayong?

Created By RISC | 6 months ago

Last modified date : 6 months ago

The fire that broke out in a chemical tank in Rayong this month will likely have far-reaching impacts for property, safety, and the environment. Let’s look at what we learnt from the incident about dealing with dangerous substances.​

Pyrolysis gasoline was stored within the tank. High-temperature decomposition of naphtha (naphtha cracking) produces olefins such as ethylene and propylene, which are precursors for making polymers and other plastics. But the process generates a byproduct known as pyrolysis gasoline, or pygas.​

So how does Pygas affect our health?​

Pygas is a hydrocarbon formed of many different components. Most of them are fragrant and have a high-octane value. As a result, it is frequently used to boost the octane amount of gasoline and serves as a precursor in the petrochemical industry. The gas is a volatile liquid classed as flammable. Its gas vapor is denser than air so accumulates at low levels rather than floating into the atmosphere. If the gas vapor travels into the air, it will harm everyone who comes into contact, causing eye and skin irritation, respiratory system problems, headaches, and nausea. Higher doses may result in unconsciousness.​

When the gas ignites, it emits soot containing carbon monoxide. If inhaled, it will affect the respiratory system. Furthermore, excessive exposure produces a lack of oxygen, resulting in dizziness, nausea, vomiting, abdominal pain, chest discomfort, and shortness of breath. Higher doses will cause unconsciousness and may result in death.​

What should we do if a fire breaks out?​​

To extinguish pygas fires, use dry chemicals, sand, or foam rather than water, as the gas vapor might ignite and rise over the water's surface, causing the fire to spread further. Avoid regions where gas is distributed, including soot and smoke from combustion. Stay in a well-ventilated place and wear a mask to avoid breathing smoke and PM2.5.​

Story by: Supunnapang Raksawong, Materials Researcher in Sustainable Building Material, RISC ​

Reference:​

Safety Data Sheet: Pyrolysis Gasoline, https://www.vitol.com/wp-content/uploads/2023/01/25.-Pygas_SDS_US_V3.0.pdf​