French authorities gave Lubrizol the go-ahead last week to resume operations at its Rouen, France, additive plant, following a late January release of harmless but foul-smelling gas that drifted as far as London.
Last Wednesday, Delphine Batho, French minister of ecology, sustainable development and energy, announced the official end of the Jan. 21 incident. According to Lubrizol, the problem began with decomposition of a batch of zinc dialkyldithiophosphate, known as ZDDP or ZDP, which released mercaptans – the same substance that is added to natural gas to give it a rotten-egg smell.
Following the release, Lubrizol was authorized to gradually resume operations at the Rouen plant. On Jan. 27 they began shipping some bulk and packaged products from the plant. On Jan. 29, they received permission to resume blending and drumming products. By Jan. 31, the company was authorized to resume operating certain intermediate units.
When Lubrizol completed the neutralization of the decomposing production batch of ZDDP last week, authorities approved resumption of all remaining plant operations except for the unit involved in the incident.
The investigation is continuing. Lubrizol is required to provide a comprehensive report on the root causes of the incident, mechanisms that lead to release of the ugly odors, measurements collected during the incident, and corrective measures to prevent any recurrence, before the local government will permit activity to resume at the unit.
French authorities emphasized that the mercaptan emissions at no time reached levels that would be adverse to health.
Lubrizol said it is executing business continuity plans to ensure security of supply to customers. The Rouen plant makes blended additives plus viscosity modifier blends and various intermediates. ZDDP is an antiwear additive blended into many automotive and industrial lube additive formulations.