The claimant applied to the planning authority for permission to erect 96 new dwellings in a location adjacent to a site which had a hazardous substances consent under s 4 of the Planning (Hazardous Substances) Act 1990 (the PHS Act). The claimant’s application for planning permission was refused, and it appealed to the first defendant Secretary of State’s planning inspectorate under s 78 of the Town and Country Planning Act 1990 (the 1990 Act). The main issue before the inspector was whether the proposed development would unacceptably increase the number of people exposed to the risks associated with proximity to the site on which hazardous chemicals were stored. The planning authority had carried out a risk assessment which accorded with the principles set out in circular 4/2000, an HSE publication which provided guidance on the operation of the consent procedure for hazardous substances provided for in the PHS Act and related subordinate legislation. That risk assessment was based on exemplar substances and maximum permitted quantities of those substances. The claimant contended, however, that the correct approach was to assess the nature of the actual residual risk by reference to specific quantities of chemicals. Following a public inquiry and a site visit, the inspector rejected the claimant’s appeal, ruling that the proposed development would constitute an unacceptable increase in the number of people exposed to the risks from the chemicals stored on the adjacent site. The claimants appealed against that decision under s 288 of the 1990 Act.
Held: Claim dismissed. The planning inspector did not have to follow the provisions of paragraph 41 of circular 4/2000. That paragraph was not relevant in the instant case, since it applied to applications for hazardous substances consents under s 4 of the PHS Act and not to planning applications for proposed new developments in the vicinity of existing hazardous installations. Further, it was for the planning inspector to decide how much weight to give the alternative approaches to risk assessment proposed by the parties. In addition, the safety controls available to the HSE focused on major accidents rather than the risks posed by an existing installation and the inspector had been entitled, as a matter of law, to conclude that ‘little weight’ should be accorded the controls having reviewed the claimant’s case and the relevant legislative provisions. Finally, whether or not the risk was ‘tolerable’ was not the relevant test in the instant case, and there had been nothing irrational in the inspector’s approach to the assessment of the evidence in respect of the risk posed to potential residents of the proposed development.