This report presents a cost analysis of Isophorone Diisocyanate (IPDI) production from isophorone and chlorine. The process examined is a typical phosgenation process. In this process, isophorone diamine (IPDA) intermediate is initially obtained from isophorone. Then, IPDA reacts with phosgene to produce IPDI. The phosgene used is generated from chlorine and carbon monoxide in an on-site unit. Hydrogen chloride (HCl) is generated as by-product. This report was developed based essentially on the following reference(s): (1) US Patent 9187412 B2, issued to Evonik Degussa in 2015 (2) US Patent 8884063 B2, issued to BASF SE in 2014 (3) US Patent 8563768, issued to Covestro (fromer Bayer MaterialScience) in 2013 Keywords: Isophorone Diisocyanate, IPDI, Isophorone Diamine, IPDA, Phosgenation