Emergency services in Essex said they had been called to Industrial Chemicals Limited, Stoness Road, in West Thurrock.
Fire crews found there had been an explosion of chemicals in a chlorine scrubbing unit.
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Half of those killed or maimed in the last 72 hours of intense bombardments in Aleppo have been children.
Astronomers said: "Europa’s ocean is considered to be one of the most promising places that could potentially harbor life".
The rain will ease in the west tonight, but the cloud cover will remain across much of England, Wales and N. Ireland.