Environmental protection authorities have ordered several Chinese chemical producers listed on the Shanghai Stock Exchange to suspend operations at their plants in Jiangsu province. Caught in what appears to be an escalation in China’s effort to curb pollution, the companies say they had to temporarily close their plants in industrial parks where authorities ordered all chemical makers to suspend operations. The companies affected include Lianhe Chemical Technology, a producer of industrial chemicals; a subsidiary of Nanjing Chemical Fiber that makes cellulose fiber; and Jiangsu Yabang Dyestuff. In statements to the Shanghai Stock Exchange, the companies report that authorities ordered all chemical plants in the Huafeng Industrial Park, the Xiangshui Eco-Chemical Industrial Park, and the Lianyungang Chemical Industrial Park to halt production. Nanjing Chemical Fiber notes that its Huafeng facility complies with regulations and had recently upgraded equipment intended to improve environmental compliance. The industrial parks where the closures were ordered were recently mentioned in the Chinese media for their poor environmental performance.