1,Benzene,16.25 micrograms per cubic metre or less, when expressed as running annual mean,31st December 2003,
 1A,Benzene,3.25 micrograms per cubic metre or less, when expressed as a running annual mean,31st December 2010,
2,1,3-Butadiene,2.25 micrograms per cubic metre or less, when expressed as a running annual mean,31st December 2003,
3,Carbon monoxide, 10 milligrams per cubic metre or less, when expressed as a running 8 hour mean,31st December 2003,
4,Lead,0.5 micrograms per cubic metre or less, when expressed as an annual mean,31st December 2004,
5,Lead,0.25 micrograms per cubic metre or less, when expressed as an annual mean,31st December 2008,
6,Nitrogen dioxide,200 micrograms per cubic metre, when expressed as an hourly mean, not to be exceeded more than 18 times a year,31st December 2005,
7,Nitrogen dioxide,40 micrograms per cubic metre or less, when expressed as an annual mean,31st December 2005,
7A,PM 2.5,10 micrograms per cubic metre or less, when expressed as an annual mean,31st December 2020,
8,PM 10,50 micrograms per cubic metre or less, when expressed as a 24 hour mean, not to be exceeded more than 35 times a year,31st December 2004,
 8A,PM10,50 micrograms per cubic metre or less when expressed as a 24 hour mean, not to be exceeded more than 7 times a year,31st December 2010,
9,PM 10,40 micrograms per cubic metre or less, when expressed as an annual mean,31st December 2004,
 9A,PM10,18 micrograms per cubic metre or less, when expressed as an annual mean,31st December 2010,
10,Sulphur dioxide,350 micrograms per cubic metre or less, when expressed as an hourly mean, not to be exceeded more than 24 times a year,31st December 2004,
11,Sulphur dioxide,125 micrograms per cubic metre or less, when expressed as a 24 hour mean, not to be exceeded more than 3 times a year,31st December 2004,
12,Sulphur dioxide,266 micrograms per cubic metre or less, when expressed as a 15 minute mean, not to be exceeded more than 35 times a year.,31st December 2005,