IRPC Public Company Limited or IRPC (Company) formerly Thai Petrochemical Industry Public Company Limited or "TPI" registered in 1978 by Leophairatana family. TPI had been transformed to a public company limited on October 10, 1994 and listed on the SET on March 17, 1995. IRPC started to produce applications of petroleum and petrochemical products in 1982 and expanded its line of production of various petrochemical products. It expanded the plant and infrastructures for fully integrated petrochemical complex.