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.
More top news
Addressing an audience in America, the former PM said of Europe's single currency that it was not working "as intended".
The countries lawmakers voted to impeach President Park Geun-hye in the wake of mass protests against her.
The former presidential candidate, who has herself been the target of false news reports, said such stories had 'real-world consequences'.