Shares of Gujarat Fluorochemicals may remain in action, as the Finance Ministry has imposed a definitive anti-dumping duty on 'methylene chloride', a chemical used in the manufacture of pharmaceuticals, agro and fragrance chemicals, from the United States and the European Union. Earlier, Gujarat Fluorochemicals and Chemplast Sanmar had filed a petition with the government seeking sunset review investigations of the import of the chemical from the EU and the US.