The FM Conway Ltd asphalt plant in Hayes, opened in 2014 and is located near the elevated section of the A312, close to Tesco Bulls Bridge. Since the opening, residents in Hayes and Southall have complained to both Hillingdon and Ealing councils about the strong malodour across both areas but of greater significance than the smell, are the health problems that appear to be linked to the air pollution. Residents have reported nausea, vomiting, headaches, throat and eye irritation, new cases of asthma, worsening of existing asthma and other respiratory disorders. There is research to indicate asphalt  fumes may be linked to cancer.

FM Conway Ltd, have increased the height of their chimney but this has not resolved the issue, so local residents urge Hillingdon council to use their regulatory powers to force FM Conway Ltd, to improve odour control, using both new and existing safety measures. Unless this happens, residents' health and wellbeing will continue to be compromised by an unacceptable level of air pollution.