[3] The maximum legal limit of nitrous oxide pollution in the United Kingdom is 40 micrograms (0.00062 gr) per cubic metre.

[14] The scheme was welcomed by campaigners for cleaner air, with one group, Asthma and Lung UK stating that Bradford had the worst hospitalisation rate in Yorkshire of children with breathing difficulties.

[11][18][19] The delays to the rollout were criticised by some taxi firms, who said that drivers had been forced to take out extensive short term loans so that they could upgrade their cars for the deadline in January, only for the scheme to be pushed back to spring 2022.

[20] The UK Government has set out the definitions of four schemes (labelled as A, B, C, and D. Bradford opted for a C-scheme (meaning it is referred to as a C-CAZ), which would see charges for all vehicles except for private cars and motorbikes.

[note 1][23] In December 2022, it was revealed that over £1.8 million in charges had been accrued from fines and levies over a twelve week period from the start date in September.

[26] A report issued in November 2024, stated that the reduced emissions had led to over 700 fewer GP appointments per month in the first year of the air zone's operation.