The United States has imposed its first antidumping duties on South Korean products since the launch of the Donald Trump administration.

The U.S. Department of Commerce announced on Monday that it assigned preliminary dumping rates of three-point-96 percent on Korean dioctyl terephthalate(DOTP) manufactured by Aekyung Chemical and five-point-75 percent duties on LG Chem after finding the firms were selling their products in the U.S. at less than fair value.

The department also imposed preliminary antidumping tariffs on imports from all Korean DOTP manufacturers.

DOTPs are chemicals that help to easily shape plastics. Korean DOTP makers have shipped about 25-thousand tons of DOTPs worth 36 billion won to the U.S. annually. As of 2015, DOTPs by Korean makers account for a combined 56 percent share of the U.S. plasticizers market.