Preventing air pollution

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Dark smoke

The darker the smoke, the more polluting it tends to be. Smoke darker than a specified shade of grey is officially classified as 鈥榙ark smoke鈥�.

The is used to define dark smoke. The chart has 5 shades of grey with 0 being clear and 5 being black. Smoke is considered 鈥榙ark鈥� if it is shade 2 or darker.

Chimney and boiler restrictions

You mustn鈥檛 release dark smoke from your premises, including from:

  • chimneys serving furnaces
  • fixed boilers or industrial plants, whether they鈥檙e attached to buildings or not

There are some exemptions if emissions won鈥檛 damage health or cause a nuisance.