Residents within a 5-kilometre radius of the factory on Soi King Kaew 21 in Rachathewa subdistrict were ordered to evacuate to avoid inhaling any harmful substances.
Firefighters were finally able to bring the flames under control on Tuesday morning after spending more than 26 hours battling the blaze.
“A preliminary investigation showed that all machines in the factory have been destroyed by the flames,” said Weerakit Ranthakitthanawat, the department’s deputy director-general.
“Some 4-5 barrels of chemical were found at the site, which we estimate could be Pentane.”
Weerakit said the chemical would be sent for proper disposal although its properties have probably evaporated by now due to exposure to the intense heat.
“Debris from the building and structures must also be disposed of according to the Hazardous Substance Act as they could be contaminated with hazardous chemicals,” he pointed out.
The department has ordered the factory to transport 1,600 tonnes of Styrene Monomer that it has in stock out of the area and dispose of them properly.
“Ming Dih Chemical is a category 3 factory [having machines greater than 75 horsepower or more than 75 employees], which is subject to risk evaluation every five years. We are investigating if the factory has been complying with this regulation,” Weerakit said.
The department also collected water samples from nearby canals to test if these contained any chemical residue.
As for air quality evaluation, the department has set up two testing stations – at Thanyathani Industrial Estate, located 2 kilometres upwind from the blast site, and at a warehouse about 1 km downwind.
The Thanyathani testing station found 0.42 ppm of Styrene and 0.55 ppm of Pentane in the air, while the other station found 0.83 ppm of Styrene and 0.81 ppm of Pentane.
According to the department’s standard of Styrene as an air contaminant, the organic compound at 20 ppm or lower will have no effect on people’s health. At 130 ppm it will have a non-severe health impact, but at 1,100 ppm there will be a severe health impact though not fatal.
Published : July 07, 2021
By : THE NATION