At 10:30 am, the personnel at a plant producing polyester products and by-products noted the presence of white smoke above a 1-m³ bin containing styrene stored in the waste zone while awaiting shipment to a waste disposal centre. The internal emergency plan was activated; the alarm mobilised the plant’s response team and external fire-fighters were called in as backup. The container that had cracked under the combined effect of high temperature and pressure, was cooled by spraying water first then foam. The cooling water (38 m³) was confined onsite and channelled to the sealed basin designed for this purpose before conveyance to a certified treatment centre. By 11:30 am, the incident had been brought under control and intervention teams had left the site.

The styrene stored in the designated waste zone stemmed from a rinsing operations on a gel-coated tank, performed as part of the shutdown procedure for the gel-coat workshop’s annual holiday. The previous days’ heat wave temperatures (40°C) facilitated the onset of styrene polymerisation, as the container had been exposed to the sun for 2 weeks. Its cooling served to block this reaction.

After this incident, the operator revised the storage conditions for wastes containing styrene, preferring to store these containers inside the finished product storeroom. The storeroom floor was fitted with sealed retention and the premises equipped with an automatic sprinkler extinction system.