Chemicals at a factory just outside the Thai capital briefly burst back into flames on Tuesday, sending another cloud of toxic black smoke into the air and highlighting the continuing health danger from an industrial accident that killed one and injured dozens more.
It took firefighters more than 24-hours to put the fire out initially after it started with an explosion at about 3am on Monday which could be heard for kilometres and blew the windows and doors out of nearby homes.
Despite efforts by firefighters to keep the highly flammable chemical styrene monomer from reigniting by continuing to douse the site with water and foam, flames broke out again and burned for about an hour on Tuesday afternoon.
Little was left of the Ming Dih Chemical factory other than the twisted metal frames and charred remains of its warehouses that were destroyed in the explosion and fire.
More than 60 people were injured in the disaster, including a dozen emergency responders, and more than 30 of them were hospitalised. One man, identified as an 18-year-old volunteer firefighter, was killed in the blaze.
Al Jazeera’s Tony Cheng, reporting from Bangkok, said the fire service announced that the fire was under control and almost extinguished “much earlier this morning”, but it flared up again.
“We were seeing huge clouds of black smoke again with chemicals in the plastic factory catching fire,” Cheng said. Some 200 residents in the area were “quickly moved out” again, he said, adding that they are wary of returning to their homes.
Though the fire service said that the blaze was under control once again, there are dangers that remain – especially that it is raining in the area which could reignite the fire by reacting with the chemicals, Cheng said.
Police questioned the factory manager in their investigation of the cause of the explosion, who told them that he and eight staff members were woken from their sleep on the site by a strong chemical smell and fled just before the blast, said Chumpol Poompuang, the district’s police commander.
Authorities ordered a 5km (3-mile) area around the foam and plastic pellet manufacturing factory – near Bangkok’s main airport – evacuated as the factory burned, telling residents to avoid inhaling any fumes and warning that they could cause dizziness and vomiting, and cancer in the long term.
On Tuesday, Attapol Charoenchansa, who heads the country’s pollution control department, said teams were testing the air quality and water in the area of the factory, and were considering narrowing the evacuation zone to allow some residents to return home.
He cautioned, however, that rain which began falling on Tuesday afternoon could wash the chemicals into water sources, which would be difficult to control.
ASEAN Parliamentarians for Human Rights, a regional advocacy group, urged the Thai government to provide the public with more information on the chemicals that had been released, as well as all of its findings on possible contamination.
It also stressed that firefighters and others working at the scene, many of whom wore only the masks required by the government to prevent the spread of COVID-19 – or none at all – as they battled the blaze, had to be outfitted with better protective equipment during the cleanup.
“Now is the time to understand what the impacts of the fire and explosion might be, and ensure that all those still operating in the vicinity are adequately protected,” said group member and Philippine lawmaker Sarah Elago.
“Seeing firefighters with surgical masks fighting against potentially cancerogenic chemicals was an atrocious sight. The government should urgently provide adequate material for all those still at risk,” she said.
Prime Minister Prayuth Chan-ocha has ordered authorities to gather as much information as possible on contamination of soil, ground water, the city’s drinking water and air so as to “mitigate the health impact in both the short and long term.”
“Although the fire is under control, our work has not yet been completed,” he said in a statement posted on Facebook.
Officials said shockwaves from the initial explosion damaged about 100 houses and 15 cars.
It was not clear how much monetary damage the fire caused to the factory.
Styrene monomer is used in the production of disposable foam plates, cups and other products, and can produce poisonous fumes when ignited.
The chemical itself also emits styrene gas, a neurotoxin, which can immobilise people within minutes of inhalation and can be fatal at high concentrations. Last year in the Indian city of Visakhapatnam, a leak of styrene gas from a chemical factory killed 12 people and sickened more than 1,000.
The area around the factory is a mixture of older industrial complexes and newer housing developments that were built after the opening of the airport in 2006.