Setting environmental standards : twenty-first report / Royal Commission on Environmental Pollution.

  • Great Britain. Royal Commission on Environmental Pollution
Date:
1998
Catalogue details

Licence: Open Government Licence

Credit: Setting environmental standards : twenty-first report / Royal Commission on Environmental Pollution. Source: Wellcome Collection.

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    for a reduction. In the intermediate band local authorities would set target levels (also envisaged as bands) in the light of local circumstances. 4.11 Statistical estimates of risk were adopted as a criterion for tolerability in guidelines published by the Health and Safety Executive (HSE) in 1988, which also defined tolerability in terms of three categories. These guidelines covered levels of individual and social risk to workers and the public from nuclear power stations and implemented a recommendation made in 1987 by the Inspector who conducted the public inquiry into the proposal to construct Sizewell B nuclear power station. 4.12 HSE’s guidelines drew on the report of the original Royal Society Study Group. They also drew on recommendations made in 1977 by the International Commission on Radiological Protection (appendix C, C.7), which, on the basis of analogies with risks regularly accepted in everyday life, set the acceptable average risk of death of a member of the public from ionising radiation in any one year in the range 1 in 1,000,000 to 1 in 100,000. It recommended absolute limits on the exposure of individual workers and members of the public to ionising radiation; and said that within those limits exposure should be kept as low as reasonably achievable (ALARA) using a cost-benefit approach.” 4.13 The three categories of risk defined by HSE are: a. where ‘a given tisk is so great or the outcome so unacceptable that it must be refused altogether’; b. where ‘the risk is, or has been made, so small that no further precaution is necessary’; c. any risk which falls between a. and 6., which should be ‘reduced to the lowest level practicable, bearing in mind the benefits flowing from its acceptance and taking into account the costs of any further reduction’. In other words this is the band in which HSE applies the general principle that levels of risk should be ‘as low as reasonably practicable’ (ALARP). 4.14 In the guidelines HSE adopted the following levels of risk, in terms of the probability of an individual dying in any one year: 1 in 1,000 as the ‘just about tolerable risk’ for ‘any substantial category [of workers] for any large part of a working life’; 1 in 10,000 as the ‘maximum tolerable risk’ for members of the public from any single non- nuclear plant; 1 in 100,000 as the ‘maximum tolerable risk’ for members of the public from any new nuclear power station; 1 in 1,000,000 as the level of ‘acceptable risk’ at which no further improvements in safety need be made. HSE set these guidelines after considering risks in other contexts. A risk of 1 in 1,000,000 is broadly the same as that of being electrocuted at home and about one-hundredth that of dying in a traffic accident.” In a revised edition of the guidelines, published in 1992, HSE noted that, although they had been produced in the context of regulation of nuclear power stations by the Nuclear Installations Inspectorate, the approach described was being applied increasingly to regulation of other major industrial risks in the UK.” 4.15 Following a government commitment made in 1992, an interdepartmental working party, administered by HSE, was established to review the use of risk assessment across government. It found that it was being used in a variety of policy contexts, with considerable agreement between Departments on what a risk assessment involves and how in broad terms it should be applied. But its use within government had not been systematically developed, and it was sometimes Dia
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