Spot ethylene prices in USA have been flat at around 50 cents/lb Mtb-Wms, failing to lift despite news of a production outage and force majeure by Shell Chemicals, as per Platts. While sources agreed supplies were tight in Louisiana, most buyers backed off as the calendar year draws to an end. A production outage was reported by Shell at its GO-1 unit in Norco, Louisiana, with a nameplate capacity of near 1.2 bln lbs/year. The plant was unexpectedly taken down due to a ruptured high-pressure steam line, forcing Shell to declare force majeure from ethylene supplies at Norco. While allocations levels were not confirmed, several participants reported 90% for December. The Norco complex has a second cracker, OP-5, which can make up to 1.8 bln lbs/year of ethylene. Two other crackers remained offline- Ineos' units at Chocolate Bayou, Texas, and Chevron Phillips' facility at Cedar Bayou, Texas.