The fire is now out at the factory in Greenwich which burst into flames in the early hours of the morning.
The area still smells strongly of the swimming pool chemicals which were stored here.
The fire brigade say those chemicals pose little health risk to anyone and are no worse than a strong bleach.
More top news
The Met Office is forecasting freezing fog for parts of London tomorrow and on Tuesday
Fans of George Michael have started a petition for a tribute bench on Hampstead Heath in his memory
Police have warned the public not to approach a 'dangerous' man after a woman was stabbed in Mitcham in south London.