HAZARDS XXII Liverpool Apr 2011 Societal

HAZARDS XXII – Liverpool – Apr 2011 Societal risk criteria in land use planning The scale of ‘scale aversion’ Ivan Vince ASK Consultants The Coach House, 14 Scotts Avenue, Bromley BR 2 0 LQ Tel: +44 (0) 20 8460 9923 Web: www. askconsultants. com

Corrections/clarifications to paper 60 • The formula following the first mention of SRI, on p 408, shows the dimensions of the population factor (P) of SRI. The formula for SRI itself appears on p 409. • The statement at the end of para 5, to the effect that HSE has a policy not to use scale aversion, is not strictly accurate: further consultation is likely to be required before the policy is adopted. • References to HSC(1991) should read ACDS(1991): the report was produced by the Advisory Committee on Dangerous Substances and presented to the Health and Safety Commission. • The calculation on p 410 somewhat overstates the conflict between R 2 P 2 and SRI. The dangerous dose is defined for a normal population, so the proportion of fatalities in a vulnerable population receiving this dose will be substantially higher than 1%. Also, the individual risk in the outer zone ranges from 0. 3 to 1 cpm/yr – the lower value applies to the outer contour of the outer zone – the Consultation Distance. NB the conclusion is unaffected: the SRI would trigger “Advise Against” in a situation where R 2 P 2 would consider the risk to be broadly acceptable without the need for further risk reduction.