HONG KONG — The police on Friday detained personnel from a chemical plant in eastern China after an explosion killed at least 47 people, setting off an inferno that firefighters battled through the night and raising fears of toxic substances spreading in the air and water.
The blast Thursday afternoon at Jiangsu Tianjiayi Chemical Company, on the outskirts of the city of Yancheng in Jiangsu Province, was believed to have caused a tremor equivalent to a magnitude-2.2 earthquake, the China Earthquake Administration said.
The explosion seriously injured 90 people, including the general manager of the plant, Zhang Qinyue. An undisclosed number of other company employees were detained after the blast, Yancheng officials said on Friday.
The cause of the blast has not been confirmed, but one worker said a tanker truck carrying natural gas had caught fire, setting off an explosion in a benzene storage area, according to a report from Caixin, a Chinese business news outlet.
More than 900 emergency personnel responded to the blast, and fires in three storage tanks and five other sites were all extinguished by 7 a.m. Friday, officials said.
The plant, which was established in 2007 in Xiangshui County, mainly produces pesticides, according to online listings. An inspection last year by the State Administration of Work Safety found 13 safety problems, including extensive leaks, a lack of safety training, “poor site management” and a shortage of operating procedures and technical specifications posted in the benzene tank area.
About 4,000 workers and residents were forced to evacuate after the blast, officials said.
The explosion, which happened shortly before 3 p.m., startled one resident from his afternoon nap. The man, who only gave his surname, Chen, lives about six miles from the plant. He said the road outside his door was soon filled with injured people.
“Glass doors and windows have all been shaken out and the poorer houses are so damaged they are uninhabitable,” he said. “The old people and children in my family have all been cut by glass shards.”
Residents now worry about the safety of their water, and some have fled out of fear of toxic air, he said.
Concerns about the chemical industry are widespread in Jiangsu, which is China’s leading producer of agricultural chemicals. A blast at a chemical plant killed seven people in Xiangshui County in 2007. Four years later, late-night rumors that flammable gas was leaking from a plant sent thousands of people fleeing, and four people were killed in a traffic accident.
China has been trying to raise safety standards following deadly explosions at chemical plants in recent years. In 2015 blasts in the northeastern port city of Tianjin killed 173 people.
Last year, at least 23 people were killed in an explosion near a chemical plant in Hebei Province.
China is the largest producer and consumer of chemicals in the world, but regulation of the industry is weak and inconsistent. Greenpeace has found that there is an average of about one chemical accident per day in China.
After the Tianjin blasts, the government expanded inspections and toughened punishments for companies that violated safety standards. But many executives have cut corners under pressure to meet strict production targets, especially as China grapples with an economic slowdown.
Ma Jun, a prominent Chinese environmentalist, said regulators did not have the resources to regulate the vast chemical industry and that businesses should do more to police themselves.
“It’s really time to focus on their behavior,” he said. “If they don’t want to be overregulated, if they want to build the trust with the public, then they must start to regulate themselves.”
The government is considering new rules that would require chemical companies to disclose more information about the production and use of hazardous substances to the Ministry of Ecology and Environment. But opposition from the industry has been fierce.
Many companies accused of violating standards find ways to get around regulatory efforts, returning to old practices after paying fines or reassigning staff. The biggest companies wield considerable clout with local officials, allowing them to stay open even if they repeatedly violate standards, advocates say.
“The tragic pattern is familiar,” said Joseph DiGangi, senior science and technical adviser at IPEN, an environmental advocacy group. “The chemical industry has externalized the true costs of its products onto the public.”