A CHEMICAL firm must retrain its staff following the escape of a toxic chemical into the River Tees.

The Environment Agency has ordered DuPont, Wilton, east Cleveland, to clean up its act and review procedures, following a month-long investigation into the spill of 700kg of titanium dioxide from the polymer plant into the river.

The pigment, used in the manufacture of nylon, escaped when a valve on a mixing container was left open while the substance was being transferred between tanks, causing it to leak.

A second valve on the sump, intended to contain such leaks, was also left open and the titanium dioxide entered the site drainage system. From there, it ran into the Tees.

The agency said the environmental impact of the leak had been assessed as insignificant and no remedial work was necessary. However, the Environment Agency still treats incidents of this nature very seriously.

As a result, an enforcement notice has been served on Dupont which requires the company to carry out a review of its containment procedures and to retrain all relevant staff, following the results of the review. Dupont must comply by December 31.

A Dupont spokesman said the company had received an enforcement notice and would comply totally with the requirements.

Howard Stuttard, regulatory support team leader, said: "Even the best-run sites must have adequate procedures in place to prevent and contain leaks to make sure that incidents of this type do not occur. There is a need to ensure that protective systems are set up to work when called upon."