Czech refiner Unipetrol's the ethylene unit is being operated without a coldbox since December 2007. Since December, ethylene production has stabilised and benzene production cut back to 80% capacity at the plant. Unipetrol plans to launch the re-instalment of the coldbox in its ethylene unit, and expects to complete the process by mid-April. The instalment is not estimated to cause any interruption in ethylene production of ethylene. Benzene production, however, will be interrupted for several days.