Emission regulations require that companies planning new olefin crackers in EPA designated nonattainment areas like Houston must buy emission credits prior to construction. The market for credits in Houston for one criteria pollutant – volatile organic compounds (VOCs) skyrocketed from $4.5K/ton in 2011 to $300K/ton this month. The scarcity of emission credits and their rising price threaten to constrain or delay new petrochemical plant builds and will continue to hamper plant development and expansions in the Gulf Coast region. Today we describe the challenge new projects face.