The 1962 London smog was a severe smog episode that affected London, England in December 1962. It occurred ten years after Great Smog of London, in which serious air pollution had killed as many as 12,000 people. While the 1952 smog had led to the passing of the 1956 Clean Air Act, which restricted the burning of domestic fuels in urban areas with the introduction of smokeless zones, fogs continued to be smoky in London for some years after the act as residents and operators were given time to convert from domestic fuels. The December 1962 smog is thought to have led to the deaths of up to 700 people.