China's Ministry of Commerce has announced an anti-dumping investigation against imports of phenol from the US, European Union, South Korea, Japan and Thailand. Phenol is a petroleum industry product, and is widely used to synthesize plastics and related materials. It is found in numerous household products and pharmaceutical drugs, like aspirin as well as detergent. According to data from China's Customs, 26% of China's monthly phenol imports came from the US on average, with 33% from South Korea, while imports from Thailand and Japan accounted for 14% and 11%. The announcement comes days after US President Donald Trump announced possible trade measures against China.