Reference tables for completing air emissions risk assessments updated

18 May 2022

The Department for Environment, Food and Rural Affairs has updated its guidance on how to complete an air emissions risk assessment.

The guidance has been updated as follows.

  • Where the ozone and sulphur dioxide concentrations are proven to be low, a daily oxides of nitrogen critical level of 200mg/m3 for detailed assessment has been included in the screening for protected conservation areas table. The 75mg/m3 daily oxides of nitrogen critical level remains in effect for all screening assessments.

  • The ozone critical levels to be used in conjunction with daily oxides of nitrogen critical level of 200mg/m3 has been added.

  • The format of the environmental assessment levels (EAL) table has been updated and EAL averaging times to the appropriate time period have been corrected:

    • carbon disulphide, hydrogen sulphide, methylene chloride and vanadium have been given 24 hour EALs rather than the default 1 hour; this makes these EALs consistent with the originally published EAL list

    • the formaldehyde short-term EAL averaging time has been amended to 30 minutes to be consistent with the original published EAL; a 1 hour to 30 minute conversion factor has been added to use with this EAL.

  • The vanadium long-term EAL has been removed as the short-term EAL is lower and more protective.

  • The UK Air Quality Strategy objective for benzo(a)pyrene has been moved out of the EAL table to the Air Quality Standards Regulations 2010 Target Values and UK Air Quality Strategy objectives table.