Rugged terrain in the mountainous region of the Sichuan province, including a thick layer of forest and lack of access to water, hindered efforts to put out the fire.
Some manufacturers evaded scrutiny by slightly modifying the molecular structures of substances. Monday's announcement "puts a wider array of substances under regulation," a Chinese official says.
Chinese companies are recruiting workers from home and subjecting them to harsh treatment abroad. In one case, laborers brought to the U.S. were forced to work 14-hour days without pay.
Meng Hongwei's case drew international headlines last fall after one of the world's top law enforcement officials suddenly lost contact with his family during a trip from France to China.
The U.S. says it may stop sharing intelligence with Germany if it adopts Chinese firm Huawei's 5G technology. But the threats haven't swayed Germany, which says it can set its own security standards.
Last year, China drastically cut back its imports of plastic waste to recycle. Now the U.S. and other wealthy nations must figure out what to do with their discards.
China's government plays a large, powerful role in how its businesses operate — giving them preferential treatment over their rivals. That's a big sticking point in U.S.-China trade talks.