Major hazards control: the local community and risk decisions and loss... · MAJOR HAZARD CONTROL : THE LOCAL COMMUNITY AND RISK DECISIONS ... have got to be assessed and discussed

I.CHEM.E. SYMPOSIUM SERIES NO. 110

MAJOR HAZARD CONTROL : THE LOCAL COMMUNITY AND RISK DECISIONS

Judith Petts *

This paper explores how r isk is being discussed and considered in local s i t i ng decisions re la t ing to major hazard ins ta l la t ions in B r i t a i n . I t considers how r isk debates and decisions can be improved to ensure that local communities can par t ic ipate e f f ec t i ve l y , and thus, have confidence in hazard cont ro l . The observations are based on the author's research into planning and major hazards over some 6 years including an assessment for the Health and Safety Executive of the effectiveness of the technical advice which i t provides to local planning au thor i t ies .

INTRODUCTION

The las t two decades have seen growing public awareness o f , and concern over, the accident potent ial of chemical ins ta l la t ions and a c t i v i t i e s . Public concern about the chemical industry has, undoubtedly, been part of a broad reaction against threats to heal th, safety, and the environment. Unfortunately the chemical industry has managed to confirm some of the publ ic 's worst fears - Seveso (1976), Bhopal (1984), Mexico City (1984). Intensive media coverage has brought the horrors of such events in to people's homes. The effectiveness of regulatory con t ro l , the competence of the chemical industry, the va l i d i t y of expert opinion are increasingly being challenged. Unless the chemical industry operates safely i t w i l l face threats to i t s freedom to operate. The public has a r igh t to be involved in decisions about hazard and r i s k , whether about safety c r i t e r i a relevant to public heal th, or about decisions about specif ic indust r ia l s i tes which could have an impact on a local community.

One of the biggest challenges facing the industry and the regulatory author i t ies is how to base development decisions on both a robust assessment of the r isks and an understanding of the perceptions of those r i sks . Risks have got to be assessed and discussed publ ic ly in an e f fec t ive and rat ional manner.

This is a challenge which faces the developed and, increasingly, the developing world. The solutions are not immediately transferable from one to the other, although the lessons of experience in the former may be of value to the l a t t e r .

*Centre for Extension Studies, Loughborough University of Technology.

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HAZARD CONTROL IN BRITAIN

In Br i ta in warning of major hazard potent ial came in 1967 in the report of the Chief Inspector of Factories (1). Early mi t igat ing measures were taken through the land-use planning system (2). However, i t was the disaster at Flixborough (3) which provided the impetus for the development of a control system for major chemical accident hazards. The vapour cloud explosion involv ing cyclohexane on Saturday 1st June 1974 at the works of Nypro (UK) Limited - which k i l l e d twenty-eight people working on the s i t e , in jured t h i r t y - s i x people and produced extensive o f f - s i t e damage - was the d i rect reason for the set t ing up of a committee of experts to iden t i f y types of ins ta l la t ions with the potential to present major hazards to employees or to the public or the environment, and to advise on measures of con t ro l . The Advisory Committee on Major Hazards (ACMH) met over nine years (1974 - 1983) and during th is period was largely responsible fo r promoting the current control system (4).

Some simple but fundamental pr inc ip les provide the framework of control :-

1 . The need to iden t i f y and assess the hazards. This has been achieved by means of the Not i f i ca t ion of Ins ta l la t ions Handling Hazardous Substances (NIHHS) Regulations, 1982 (5) ; the Control of Industr ia l Major Accident Hazard Regulations, 1984 (6) ; and w i l l be strengthened by 'Hazardous Substance Consent' (7).

2. The need to avoid accidents through good engineering design standards; good operation and maintenance; minimising inventor ies; good protection devices; sound management.

3. The need to mit igate the residual r isks by separation of ins ta l la t ions from the public through land-use planning, and by emergency planning.

The primary respons ib i l i t y for cont ro l l ing and minimising r isks l ies with the industry i t s e l f through the Health and Safety at Work etc Act (HSWA) 1974, with th is respons ib i l i ty enforced by the statutory safety author i ty -the Health and Safety Executive (HSE). HSWA requires that plants should be operated as safely 'as is reasonably p rac t i cab le ' . In an author i ta t ive judgement (Edwards v NCB 1947), th is was interpreted to mean that a computation should be made whereby the costs ( in time and money) of taking steps to avert the r isk are compared with the r isks themselves, and the respons ib i l i t y is discharged only i f there is a gross disproport ion. I t is a legal duty (HSWA, S.3) that operators consider the o f f - s i t e r isks to the public in th is 'computation'. Given the requirement to operate as safely as is reasonably practicable there w i l l always be a residual r isk which must be mit igated. Safety issues always have to be weighed against other factors -economic and soc ia l ; and land-use planning control of the residual r isks requires that decisons on acceptable levels of safety are made j o i n t l y between industry, the au thor i t ies , and the local communities.

LAND-USE PLANNING AND MAJOR HAZARDS

Town planning in Br i ta in has i t s roots in the public health acts of the nineteenth centruy with the f i r s t leg is la t ion concerning 'planning' in 1909. However, our formal land-use planning system dates from 1947. The primary and d i s t i nc t i ve function of planning is embodied in i t s power to control land uses so that wh i ls t the land requirements of the community are met adequately potent ia l ly incompatible land uses are spat ia l l y separated. Planning control is exercised by the two functions of forward planning and development

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control. County/Regional councils are respnsible for long-term strategic planning. The District Authorities (some 465) are responsible for the production of local plans which identify land-use needs and constraints over a 10-15 year period, and most importantly the control of development through a system of planning permission.

Authorities grant planning permission, with, or without, conditions, or refuse permission for new development in the light of 'material considerations'. Developers have the right of appeal to the Secretary of State for the Environment against refusal. Once planning permission has been granted the local planning authority has few practical means by which the decision can be reversed or land uses discontinued as such action requires compensation of the developer by the authority.

Central government policy and thinking on particular subjects is presented in Circulars, Planning Policy Guidelines, etc. Whilst there is potentially powerful supervision and control at the central level (for example, through Secretary of State decisions on the granting of planning permission following a public inquiry), the bulk of planning decisions are exercised at the local level by committees consisting of planning authority officers and elected members. There is an explicit duty on authorities to allow public participation at both the local plan and development control stages. The 1985 Local Government (Access to Information) Act required that planning files containing information used by a committee in its decisions must be open and committee meetings formally open to press and public.

The formal and widespread consideration and control of hazard in the planning process is a comparatively recent phenomenon (8). It is only since 1972 that hazard has been a material consideration in the planning process, and it was not until the NIHHS Regulations came into force in 1982 that many authorities became fully aware of the number and location of existing installations. Specific guidance on the need to consider hazard in local plans was not forthcoming until 1984, when further development control guidance was also produced (9). Furthermore, deficiencies in planning powers in terms of not being able to prevent the creation of hazardous installations where no actual 'development' took place (e.g. changes of operation on existing industrial and warehouse sites) are only now being completely overcome. 'Hazardous substance consent' will be required for all existing installations, as well as new installations, having hazardous substances at specified threshold levels. The local planning authorities will become hazardous substance authorities. They will grant consent and attach conditions relating to how and where substances are stored and used on a site.

Consideration of hazard requires technical knowledge which planners generally do not have, therefore, since 1972, the HSE has acted as a source of technical advice to planning authorities. It has provided the authorities with appropriate 'consultation distances' around installations within which planning authorities should consider the risks to new development, and provides guidelines on development which is acceptable and unacceptable. HSE advises the authorities about the risks associated with development, indicating the level of risk and its planning significance, i.e. whether or not planning permission should be refused on grounds of safety. There are some 1600 existing major hazard sites across 400 authorities. In an urbanised country with a long industrial history and only a comparatively recent identification of the hazard potential of certain industries it is to be expected that some hazardous installations are in close proximity to residential populations. In some places 20,000 people are within 1km of an

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i n s t a l l a t i o n . There are probably some 2000km2 of land which are subject to land- use planning consideration of the r isks to fur ther development. The HSE receives over 4000 consultations per year from planning au thor i t ies .

HSE's advice is based upon an object ive to encourage a s t a b i l i s a t i o n , and where possible a reduction i n , the ex is t ing levels of r isk and also, in the longer term, to prevent future increases in r isk (par t i cu la r l y societal) which might arise in the absence of adequate control (10). Thus, HSE might advise against s ign i f i can t (by size of the development and vu lnerab i l i t y of the occupants) new development and author i t ies could be encouraged to allow old buildings to go out of use. I t has to be stressed that th is is the HSE's po l icy . Planning Circulars and guidance issued by the Department of the Environment do not recognise such an e x p l i c i t po l icy . In many respects th is s i tuat ion re f lec ts the fact that hazard has been grafted onto the planning system as a specif ic considerat ion. Problems have arisen where ex is t ing ins ta l la t ions are re la t i ve ly poorly located in terms of proximity to populations and where pressure for new development is now complicated by newly i den t i f i ed r i sks .

The HSE cannot d i rect planning decisions, although i f i t considers that an author i ty is behaving irresponsibly over a r isk decision i t can ask the Secretary of State for the Environment to ' c a l l - i n ' the case for his own decision. This has only been done once. The planning author i t ies receive HSE's advice and then have to determine i t s signif icance in the overal l planning decision themselves. Bringing r isk into land-use planning has highl ighted the very d i f f i c u l t nature of safety decisions which involve the balancing of costs ( r isks) and benef i ts ; i t cer ta in ly has had a considerable impact on the information requirements of local au thor i t ies . The l a t t e r is a re f lec t ion of the fact that local communities have, d i r ec t l y and i n d i r e c t l y , been drawn into r isk decisions. Whilst i t is the local author i ty that is d i rec t l y responsible for the planning decision, th is decision is dictated by local concerns and by the economy. Public perceptions, real and po ten t i a l , do strongly influence the au thor i ty ' s decision, a l l may be influenced by the media and by the importance and involvement of the industry l oca l l y . I t is very important to consider planning decisions as community decisions.

PUBLIC PERCEPTIONS

Psychometric studies of public perception of r isk (11-13) have shown that people apparently regard as more r isky those a c t i v i t i e s which are involuntary; have potent ia l ly catastrophic consequences; involve 'new' or 'h igh ' technology; would appear to give an inequitable d i s t r i bu t i on of r isks and benef i ts ; and where the r isk is 'immediate' or easy to imagine. Green's work has iden t i f i ed large- scale chemical plant and nuclear plants as being viewed by people in a completely d i f fe ren t manner to other hazards, somehow on a scale of 'badness' a l l of the i r own (14). Lee has seen those a c t i v i t i e s which provide a threat to society as a whole, rather than j us t the i nd i v i dua l , as a t t rac t ing par t icu lar concern (15).

Certainly a l l such studies would seem to suggest that there is the potential for general public reaction against the chemical industry. In fac t , in B r i ta in at least , d i rect public reaction to hazardous ins ta l la t ions has been geographically e r r a t i c ; small scale in terms of the numbers of people involved; extremely local ised (the NIMBY - 'Not in My Back Yard' -syndrome); unsustained; and with l i t t l e involvement by the established environmental movement. Public reaction at the local level has cer ta in ly had an impact on the control system. For example, at Canvey Is land, on the Thames, public concern over the agglomeration of petrochemical industry was

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instrumental in forcing a re-examination of s i t i ng decisions and consideration of the need to discontinue operations at a B r i t i sh Gas methane terminal (16). At Mossmorran a local action group forced a more detai led consideration of the r isks involved in s i t i ng a new NGL plant and ethylene cracker (17). In a few cases operators have abandoned plans to locate at certa in s i tes because of local concern. Union Carbide happened to be looking to develop (a non major-hazard plant) at Livingston in Scotland at the time of the Bhopal tragedy. Local residents were successful in persuading the local author i ty not to grant permission, despite local employment needs, simply because i t was Union Carbide and the immediacy of the Bhopal tragedy in the media. However, in other places local concern has been ei ther apparently non-existent or very weak.

On a day to day basis i t seems that the general public are not aware o f , and (where they are) do not worry unduly about, major accident hazards (18). Experience in Br i ta in suggests that the f i r s t hazard in an area can generate the NIMBY reponse i f there are members of the local community su f f i c i en t l y knowledgeable and able (with time and money) to become involved, e.g. Mossmorran. Examination of planning decisions reveals that reaction to already established hazards, which may for example want to develop fu r ther , is influenced by the local economic importance of the industry; the record of the s i te in terms of incidents and disturbance; and the degree of involvement of the industry in the local community (8). I t has been suggested that those who l i ve nearest to hazards can be less concerned because they are fami l ia r with the hazard (13). There is some evidence in B r i t a in that f a m i l i a r i t y may induce acceptab i l i t y , or rather tolerance, witness the lack of any major reaction against the industry on Teesside and the Mersey estuary. However, i t does seem that th is f a m i l i a r i t y has to be accompanied by a good plant operating record, openness, and the plant must be loca l ly economically important. Certainly the media can play an important role in h igh l igh t ing , or not h igh l igh t ing , hazard issues (19).

PLANNING DECISIONS ON RISK - THE INFLUENCES

Local planning decisions on r i s k , are rarely made eas i ly . There are a number of important, and sometimes c o n f l i c t i n g , factors which influence such decisions and which are common to the majori ty of local au tho r i t i es : -

1. PUBLIC ACCOUNTABILITY - the local author i ty is d i rec t l y accountable to the local community and is very aware that i f a decision is made, for example, to extend a hazardous plant or to locate houses close to an i ns ta l l a t i on and there is an accident which af fects the public the authori ty w i l l be tarnished with a degree of respons ib i l i t y . Any local public concerns about a s i t e , real and even po ten t i a l , w i l l exacerbate the au thor i ty ' s decision problem, pa r t i cu la r l y when the issue becomes the focus for media a t ten t ion .

2. NEED FOR DEVELOPfOT - however, despite the above observations many local author i t ies are under considerable pressure to encourage any development which w i l l provide for economic growth and employment, to minimise res t r i c t ions on development of an ex is t ing industry, to encourage take-up of vacant and dere l i c t plots wi th in urban areas.

3. PRECEDENT - in a developed country with a long establ ished, but only recently recognised, major hazard problem many author i t ies are concerned about being seen to apply 'double standards' i f they refuse fur ther development close to an i ns ta l l a t i on when there is already s imi lar development at the same distance and often even nearer. This type of

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pressure is most common where small-scale development is involved, yet several small-scale schemes can, together, lead to an accumulation of population which in r isk terms may be undesirable.

4. FINANCIAL IMPLICATIONS - r es t r i c t i ng land use because of a nearby hazard can have a considerable influence on land values when land might fetch well over £100,000 per acre (and £1 m i l l i on per acre is increasingly common) i f sold for housing, but perhaps only a quarter of th is i f sold for warehousing. New development in the v i c in ty might r e s t r i c t fur ther development on the hazard s i t e , and vice versa.

5. TECHNICAL KNOWLEDGE - the majority of local author i ty o f f i cers (and cer ta in ly elected members) are not technical ly trained in hazard issues. They are r e l i an t on expert advice from elsewhere. Whilst in author i t ies with large-scale chemical industry o f f i cers may have the opportunity and need to become 'hazard l i t e r a t e ' , for the majority of local planning author i t ies hazard only rarely becomes a planning issue. Thus, when hazard issues do have to be balanced against other planning considerations, and the acceptabi l i ty of r isks judged, inexperience compounds lack of knowledge.

Table I - Risk/Benefit Factors in Planning Decisions a. A new major hazard i n s t a l l a t i o n / a c t i v i t y

Costs/Risks

A new r isk of harm to members of an exist ing population Bl ight ing of land as fur ther development in the v i c i n i t y may be constrained Local community concern Impact on land value/ house prices Environmental impact Resources - emergency planning, monitoring

Benefits

1. Employment-Direct and Indirect

2. Local rates income

3. Industrial growth

4. New infrastructure - e.g. roads

b. Development in vicinity of an existing major hazard installation

Costs/Risks Benefits

1. Risk of harm/death to a new population

2. Increase in number of people at risk

3. Possible restriction on further development at the hazardous installation

4. Resources - emergency planning

1. A needed development -housing, employment, services

2. Beneficial use of derelict/ vacant land

3. Maintenance of land values 4. Completion of planned

development of an area 5. Beneficial use of urban land

thus protecting rural areas

Table 1 indicates some of the risk/benefit factors which have been seen to play a part in local community decisions on risk in Britain, first (a) in relation to a new major hazard activity, and, secondly (b), in relation to development in the vicinty of an existing installation. The important point to emphasise is that the factors listed will have a different degree of

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importance attached to them according to which of the two types of decision are involved, and also according to d i f fe ren t circumstances and l o c a l i t i e s . Thus, for example, although the r isk of harm and death to a population is a cos t / r i sk influence in both decision si tuat ions i t may vary in prominence between the two - generally being more prominent in re la t ion to the new hazard because of potent ial d i rect public concern.

Certainly the r isks and benef i ts can vary in importance according to l o c a l i t y . In some urban locations there is considerable pressure for redevelopment of town centres and the encouragement of new development to replace decl ining industr ies. The larger the pressure for new development the more tolerable the r isks to that development from ex is t ing hazards may be, or conversely there may be pressure from the local authori ty to have the hazard removed, but only i f central funding can be made avai lable. At Middlesbrough (North-East England) the d i s t r i c t and county council bought out the ethylene-oxide process on a Carl ess Chemicals s i te for £800,000 provided by the Government through the Urban Development Fund. Here the HSE had advised the local author i ty that the r isks from the process were high enough to warrant abandonment of a scheme for redevelopment of part of the town.

When there is l i t t l e pressure for development in the v i c i n i t y of a hazard, par t i cu la r l y in areas where conservation is more important, then planning decisions may be taken more easi ly i f development can be refused on grounds other than r i sk . In these areas the d i f f i c u l t decisions can come when there is pressure for extension of the hazard - i t may be an important local employer and i t may need to d ivers i fy i t s business to survive, however, the local community may perceive a potential increase in the r i sks .

HSE POLICY AND PLANNING ADVICE

The constraints and influences on land-use planning decisions, and the involvement of local communities in r isk decisions, have had a considerable impact on the development of s i t i ng pol ic ies for hazardous industry and most par t i cu la r l y on the advice provided by the HSE. The main impacts have been:-

i . the development of pragmatic s i t i ng advice which has to deal with the rea l i t i e s of already well developed urban areas;

and i i . the use of quant i f ied r isk assessment (QRA) as an aid to s i t i ng decisions.

There are no specif ic national s i t i ng pol ic ies for new non-nuclear hazardous industry. However, in response to the problems of development in the v i c i n i t y of ex is t ing ins ta l la t ions HSE has sought to develop pol ic ies for cont ro l . In the very early days of advice to planning author i t ies the HSE suggested 2km radius consultation zones (measured from the boundary of an i n s t a l l a t i o n ) . Increasing f a m i l i a r i t y with the planning process and advances in hazard assessment techniques have led to considerable e f f o r t to reduce the consultation zones (and thus consultation workload); to ra t iona l ise the consultation c r i t e r i a ; to devise pol ic ies for development in the v i c i n i t y of specif ic major hazard s i t es ; and to devise specif ic po l ic ies for the most common substances (LPG -60% of a l l s i t es , and chlorine - 8% of a l l s i tes) which w i l l eventually allow for author i t ies to proceed without having to d i rec t l y consult the HSE. The largest consultat ion zones are now 1.5km with 500m or less for the majority of i ns ta l l a t i ons . HSE's assessment techniques for development ' i n the v i c i n i t y ' are used in a s imi lar way when considering the s i t i ng of new major hazard i ns ta l l a t i ons . However, the judgement of the signif icance of the assessment may be d i f fe ren t .

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ACMH, in its Third Report, suggested that policies for separation of the public from hazardous installations should aim to give 'almost complete protection for lesser and more probable accidents' and worthwhile protection for major but less probable accidents'. This 'protection' concept has largely formed the basis for HSE's advice to planning authorities. Thus, for example, in developing a policy for development in the vicinity of installations storing LPG in bulk pressurised tanks HSE considered as 'lesser and more probable' events pipework failure. BLEVE (Boiling Liquid Expanding Vapour Cloud Explosion) and VCE (Vapour Cloud Explosion) are regarded as 'major' events (20). HSE set the outer consultation zone boundaries for such sites at a distance where the consequence level for a BLEVE fireball would be a received radiation dose of 200 kJ/m2 - a level likely to cause the blistering of exposed skin in the average population but which in very elderly people could be fatal -, and an overpressure level of 1 psi for a VCE, - a level likely to cause window breakage and some injuries from flying glass but possibly some fatalaties from shock in sensitive people.

As examples, the consultation zone for a single 25 te LPG tank (the threshold for Notification under NIHHS and for Hazardous Substance Consent) was set at 250m from the boundary of the installation, for a 300 te tank 600m from the boundary. These outer boundaries merely set the line within which it was considered prudent for planning purposes to consider the risks to new development. Of course, the risks to a development are not simply a function of the consequences and likelihood of release events. The type of development is of fundamental importance, and, in assessing the risk the HSE considers several factors concerning the nature and purpose of that development (Appendix II of ACMH 3rd Report):-

(i) the inherent vulnerability of the exposed population (compare : children, elderly, disabled, average);

(ii) the proportion of time spent by any particular individual in the development (compare : home, workplace, shop, hospital, leisure centre);

(iii) the number of people who may be present at the development; (iv) whether people are likely to be indoors or outdoors, and, if

outdoors, how easily/quickly they could seek shelter; (v) the ease with which evacuation or other emergency measures

could be implemented; (vi) the type of construction, height of buildings, methods of

ventilation of buildings at the development.

HSE 'Categorises' development (using 4 categories) according to such factors. Within the consultation zone for an LPG installation it identified an inner zone within which many types of large developments e.g. educational and institutional accommodation, housing, hotels, caravans, large retail and leisure facilities - would be unacceptable because people would either be particularly sensitive or would be present for most of the time or in large numbers. However, within the inner zone, and thus throughout the consultation zones certain types of development are always acceptable, i.e. where it is considered that the risks would not normally be large enough to justify control. Included are developments which do not cater for additional people, or only very small numbers; where individuals may be present regularly but not full-time; and particularly developments where people might readily be incorporated into an emergency scheme and are not particularly vulnerable to the effects of the hazard - e.g. low density (less than 100 employees and less than 3 storeys high) offices, factories, and warehouses;

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single small shops (less than 250m2 floorspace); car parks for less than 200 vehicles; public open space; housing less than 10 units (which will not set a precedent for development or be closer to the installation than existing development). For some of these latter developments the risk to an individual person may not be very low but on societal risk grounds (the chance of a number of people being harmed) the risk is considered to be small.

The planning advice based on the protection concept has always involved quantification of the effects of an incident - but only a qualitative assessment of the probabilities. Increasingly, however, the HSE has come under pressure to quantify the risks which it is assessing. The Canvey Report (21) represented the first publicly available QRA for a major chemical hazard produced in Britain and it alerted many to the potential of the technique. QRA can provide a good overview of the nature of the risks in a system; enables different risks to be put into perspective; highlights those risks which require particular attention; and allows a larger number of people to participate in discussion on risk by reducing qualitative judgements to numbers.

HSE advice to planning authorities has frequently been criticised because of its inherent subjectivity, with advice usually being couched in terms of 'substantial' or 'negligible' risk. Pressure from local authorities for quantitative assessment has reflected their need to put the risks from the chemical industry, and in particular the 'worse conceivable accident' scenario, into perspective. QRA can be used to demonstrate that a risk is low rather than having to rely on a qualitative judgement which attempts to discount an obvious potential (although possibly extremely unlikely) hazard. HSE has devised a basic computerised quantified risk assessment system -RISKAT (22,23) - which has first been used for routine QRAs for toxic substances and in particular devising a policy for control of development in the vicinity of chlorine installations (24). Work on developing QRA for installations giving rise to fire and explosion hazards is described in a paper in this symposium (25).

When carrying out QRA the design and operation of the plant is reviewed and possible modes of failure of pipework and equipment are assessed. The probability of each failure is determined and the release rate and spread of material is calculated. For each release the probability of injury is estimated as a function of distance, direction, weather type, the category of development. To deduce values of individual risk and societal or group risk from toxic hazards the HSE has identified a toxic load criterion above which there is a clear possibility of serious injury and possibly death for the most sensitive, with severe distress to everyone, and most people requiring medical treatment (26). This approach appears to have been favoured by the HSE over the use of probit equations of risk of death based upon animal data. Certainly the 'dangerous dose' concept does seem to provide for the public's perceptions which indicate concern not just about death but also serious injury and impact on a community, and also society's concern about harm to particularly vulnerable members of a community. The development of RISKAT now enables HSE (where necessary) to provide planning authorities with plots of risk contours for individual risk and cumulative frequency (F/N) curves to indicate societal or group risk. In general the assessments produced by RISKAT are considered to give cautious best estimate values of the risks.

DECISION EXPERIENCE

Of the some 4,000 applications for development considered by the HSE every

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year in over 80% of the cases i t is able to advise that ' the r isks of harm to people at the development would be su f f i c i en t l y low that the HSE would not wish to advise against the granting of planning permission on grounds of r i s k ' . Where HSE does suggest refusal of planning permission on grounds that the r isks of harm are substantial i t s advice is largely heeded (27). Most author i t ies would f ind i t extremely d i f f i c u l t to allow development where the statutory safety authori ty had iden t i f i ed an important r i s k , the public implications of such a decision being potent ia l ly serious. In many of these cases there are also other planning reasons for refusing the development. However, there are a few author i t ies who do, or could, take decisions against the HSE's advice most par t i cu la r l y when faced with some of the decision pressures iden t i f i ed ea r l i e r .

TABLE 2 - Examples of r isk decision-making

*As i n Dept. of the Environment C i r c u l a r 9/84

Table 2 i l l u s t r a t e s 5 ac tua l p lann ing d e c i s i o n s . A l l the cases r e l a t e t o development in the v i c i n i t y of ins ta l la t ions stor ing and/or using chlor ine. The HSE's advice in each case was based on a RISKAT output providing indiv idual r i sk f igures of the r isk of receiving a 'dangerous dose', although in some cases the actual advice was based substant ia l ly on the societal r isk implications of the development - most pa r t i cu la r l y for the re ta i l developments. The actual r isk f igures which formed the basis of the advice were given to the author i t ies in four of the f i ve cases although in only two of the cases was th is information discussed in publ ic .

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The cases resulted in ei ther ' subs tan t ia l ' or 'marginal ' r isk advice from the HSE in l ine with Department of the Environment guidance. Marginal r isk advice indicated that the HSE regarded the r isk as i nsu f f i c i en t in i t s e l f to warrant refusal of planning permission but that i t could be added to other planning reasons for refusal ( th i s form of advice is less l i k e l y to be used in future fol lowing demands for more specif ic advice). Case 2 i l l u s t r a t e s the use of the 'marginal r i s k ' response. This development was for some 50-60 houses 750m from chlorine storage with r a i l tanker unloading f a c i l i t i e s . The r isk levels in themselves were not f e l t to be high enough to warrant refusal of planning permission on risk grounds alone. However, there were other planning reasons for re fusa l , in par t icu lar the s i te was ex is t ing open space wi th in a v i l lage environment, and new housing could hinder fur ther development of the major hazard i ns ta l l a t i on i t s e l f (a major petrochemical s i te of local and national importance). The developer appealed to the Secretary of State against the planning author i ty 's refusal of permission and a public inquiry was held at which the HSE presented i t s r isk advice. The Secretary of State agreed with the f indings of the inquiry inspector that the advice from the HSE should be ignored only i f there were overr iding considerations of need for housing land. He considered the main issues to be the proximity of the i ns ta l l a t i on and the r isks (a 1 0 - 5 - 10"6 per year r isk of a house resident receiving a 'dangerous dose' of chlor ine) to any future residents. The appeal was dismissed.

Cases 3 and 5 i l l u s t r a t e (rare) s i tuat ions where planning author i t ies have granted planning permission for development against the advice of HSE. The HSE's advice in case 3 was based on the vu lnerab i l i t y of the potent ial occupants of the old people's home and the fact that refusal of planning permission would represent an opportunity to s tab i l i se the population at r i s k . However, th is par t icu lar author i ty granted planning permission because of the need for accommodation for the elder ly in the area, the small size of the development, and the fact that there was already considerable other development close to the hazardous i n s t a l l a t i o n . The par t icu lar i ns ta l l a t i on has been in existence a long time and some of the planning committee members seem to have a certa in level of t o l e r a b i l i t y of the r isks based on f a m i l i a r i t y . A s imi lar s i tuat ion exists in the author i ty involved in case 5. This par t icu lar re ta i l development would bring some 55 jobs to a depressed area and was seen as providing much needed shopping f a c i l i t i e s , therefore despite the advice of the HSE (based on a societal r isk f igure of a 5 x 10-4

per year chance of harming 10 people which was provided to the author i ty in the form of an F/N p l o t ) , permission was granted although there was some concern in the planning committee about granting permission contrary to HSE advice. Cases 3 and 5 demonstrate the very d i f f i c u l t problem of dealing with ' res idua l ' r isks in planning and the considerable d i f f i c u l t y which faces the HSE in explaining th is concept.

RISK ASSESSMENT AND CRITERIA

Whilst few local planning author i t ies go against the HSE's advice th is in no way indicates that decisions are taken eas i ly . The evidence of cases where the HSE's advice is set aside underlines the d i f f i c u l t i e s which beset decisions involving a balancing (however obscure) of r isks and benef i ts . Few local planning author i t ies are accustomed to balancing physical (as opposed to economic) r isks in the i r decisions and the majority are very unsure as to how to handle r isk f igures such as 1 x 10 - 6 per year. However, a noticeable feature is that many author i t ies have decided that in order to make e f fec t i ve , and publ ic ly accountable, decisions they need a quant i tat ive assessment and some means of comparing the l a t t e r with other r isks (8) .

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Such information demands re f lec t a continuing desire for decisions on r isk to be able to be made at the local l e ve l . In the Netherlands central government has determined f ixed c r i t i c a l r isk levels for major hazards, one below which r isks are considered negl ig ib le and a higher one above which r isks are unacceptable. The distance between these levels const i tutes a grey area where r isks should desirably be reduced. These national c r i t e r i a are implemented at the local level with central involvement. Such an approach can promote common equitable r isk standards na t iona l ly , bring consistency in decision- making and allow developers to know what and what w i l l not be acceptable. However, such an approach may devalue a community decision on local acceptab i l i t y , and i t is dependent on a robust r isk assessment. Given tha t , depending on the method of assessment chosen, an individual r isk contour could vary in locat ion by a hundred or more metres, yet development wi th in the contour may be designated unacceptable, the uncertainty in the r isk quan t i f i ca t ion , even i f known, can be extremely d i f f i c u l t to handle (28,29).

A more f l ex ib le approach, as has so far happened in B r i t a i n , allows for local community concerns and local economic factors to be dealt w i th . The uncertaint ies in the r isk assessment s t i l l need to be known and considered but the f i na l decision is not so dependent upon the assessment. However, experience in Br i ta in indicates that an e f fec t ive f l ex ib l e approach does require some guidelines on r isk t o l e r a b i l i t y which local communities can use as an aid to (not a method of) decision-making and that th is approach is very demanding in terms of information a v a i l a b i l i t y .

Despite the HSE's progress to quant i f i ca t ion i t has not, as y e t , made known the c r i t e r i a upon which i t judges whether a r isk from a major accident hazard is ' subs tan t ia l ' or ' n e g l i g i b l e ' . The Layf ie ld Report of the public inquiry into the bui ld ing of a PWR nuclear power stat ion at Sizewell in Suffolk recommended that the HSE should make known the ' to lerable levels of individual and social r isks to workers and the public for nuclear power stat ions ' having regard to ' the benefits of nuclear power as well as to the par t icu lar features of the r isks i t creates' (30). The author's own assessment of the effectiveness of the HSE's advice to planning author i t ies on major hazards i den t i f i ed a need for the HSE to explain i t s judgements on r isks in individual planning cases and to make known the c r i t e r i a of r isk acceptabi l i ty which i t adopts (27). Indeed i t s use of QRA for planning advice could be seen as largely i r re levant unless i t does make known these c r i t e r i a .

The Royal Society Study Group on Risk Assessment (31) proposed a three-band approach for c r i t e r i a of individual r isk from involuntary hazards. In the top band (above 10~3 per year r isk of death) i t f e l t that the r isk is c lear ly un jus t i f i ab le . At the lower level (below 10 - 6 per year r isk of death) i t f e l t that the r isk is l i k e l y to be regarded as t r i v i a l . In the middle band the r isk may be managed by comparing r i sks , costs and benef i ts . In the absence of published HSE guidel ines, the Study Group's c r i t e r i a have formed a basis fo r discussion in a number of land-use planning decisions, however, there have been problems in the i r use:-

i . There is no attempt to deal with societal or community r i sks .

i i . The f igures refer to a r isk of death to a typical person, in a par t icu lar period of t ime. This is not a useful test for many types of development which may, for example, be dealing with e i ther par t i cu la r ly sensit ive people, or with large numbers of people present fo r a short t ime.

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i i i . The 10 - 3 per year r isk of death top band stressed the s i tuat ion of an informed person deriving d i rec t benef i t from the r i s k . This may not always be relevant in the s i tuat ion of the involuntary r isks presented by major chemical hazards. In the l a t t e r cases the top band w i l l need to be lower - (indeed for ' large-scale indust r ia l hazards' the HSE has j u s t suggested a maximum level of to lerable individual r isk of 1 in 10,000 per annum, in response to Layf ie ld (32)).

i v . Individual r isk of death does not deal wi th public concerns about serious i n j u r i e s , disrupt ion to a community, property damage, e t c . , although i t is more readily comparable with other f igures on r isk of death.

Cr i te r ia of r isk t o l e r a b i l i t y for land- use planning in re la t ion to major hazards need to be able to deal with three d i f fe ren t si tuat ions -( i ) new development in the v i c i n i t y of ex is t ing major hazards, ( i i ) new major hazards near ex is t ing housing, ( i i i ) new major hazards on 'g reenf ie ld ' s i tes . Di f ferent c r i t e r i a may be appropriate for ( i ) than for ( i i ) and ( i i i ) , and fu r ther , d i f fe ren t c r i t e r i a may be appropriate for ( i i ) and ( i i i ) . In par t icu lar less str ingent c r i t e r i a may be appropriate for new major hazards on 'g reenf ie ld ' s i tes as further development in the v i c i n i t y could be prevented. In the case of new major hazards near ex is t ing housing the HSE has suggested that i t may be appropriate to accept less str ingent c r i t e r i a than for development in the v i c i n i t y because there may be fewer a l ternat ive locations for the hazardous development than for new housing, and because better safety devices could be b u i l t into a new plant than i t would be appropriate (under the test of 'reasonable p r a c t i c a b i l i t y ' ) to seek on an old s i te (Appendix I I of ACMH Third Report). However, experience of local community reaction to major hazards indicates that c r i t e r i a for new hazards which were less str ingent than for development in the v i c i n i t y might be p o l i t i c a l l y d i f f i c u l t to handle. People l i v i ng in an area expect to be protected against the imposition of a new r i sk . The argument that there are fewer si tes available for hazardous industry, than say for housing, is acceptable in a national context, but at the local level can be seen to be unacceptable (unless i t is an ex is t ing major hazard which is economically v i ta l and needs to expand or develop).

For development in the v i c i n i t y of ex is t ing hazards c r i t e r i a need to be able to allow for the d i f fe ren t sens i t i v i t i es of people - thus more str ingent s i t i ng c r i t e r i a may be appropriate for development involving the elder ly and the sick when the 'dangerous dose' is more l i k e l y to be l e t h a l . Developments involving large numbers of people require an appreciation of societal r isk and s i t i ng c r i t e r i a for these may need to be more str ingent than for small-scale developments which would lead only to a small increase in societal r i sk . There are also certa in types of development which have a ' p o l i t i c a l ' sens i t i v i t y - e.g. schools and ins t i t u t i ona l accommodation -where the public may expect a greater level of protect ion.

Any r isk c r i t e r i a u t i l i s e d by the HSE in the provision of i t s advice to planning author i t ies could, arguably, need to consider the national implications of cumulative r isks with the HSE as the statutory safety author i ty seeking to avoid an unacceptable national increase in societal r i sk . However, HSE's advice is u t i l i s e d at the local community level where every planning decision is a ' one -o f f and where acceptabi l i ty decisions w i l l vary with time. There is l i t t l e evidence from such decisions that the concept of a c r i t e r i a for national r isk would be wholly acceptable. Certainly there would seem to be problems in t ry ing to derive c r i t e r i a from

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past decisions. As table 2 i l l u s t r a t e s what may be an acceptable, or to lera ted, r isk can be time and circumstance dependent.

The t o l e r a b i l i t y of r isks w i l l not be discussed adequately unless ways of e f fec t i ve ly expressing them can be found. Typical ly in planning decisions individual r isks of death from major hazards have been compared with other r isks e.g. being h i t by l i gh tn ing , car accidents, r isks of dying at work. The HSE's move to use of the 'dangerous dose' over the l as t two years, wh i ls t more adequately dealing with public perceptions, makes comparisons with other r isks of death more d i f f i c u l t . There is a need to look for some comparative data which deal with other involuntary catastrophic r isks where serious in ju r ies are at least as numerous as deaths and where government control is expected by the public e.g. f i r es in public places, coach or t ra in accidents. Conveying and expressing societal r isks has so far proved the most int ractable problem. Notwithstanding the technical problems of understanding the signif icance of cumulative frequency curves there is the problem of the two-dimensional de f in i t i on of societal r i sk . I t would be useful i f societal r isk could be reduced to a single parameter, but th is may represent an over -s imp l i f i ca t ion .

LESSONS FOR RISK DECISIONS AND SITING POLICIES

QRA is now a necessary component of any public decision process where r isk is a dominant issue, and the planning author i t ies do need to have guidelines on the accep tab i l i t y / t o l e rab i l i t y of the r isks from hazardous i ns ta l l a t i ons . Yet these guidelines are only part of the whole demand for more information on hazards and r i sks . There is a considerable need for better explanation o f , and t ra in ing i n , hazard issues which must come not only from the statutory au thor i t i es , but also from the industry i t s e l f . Examination of land-use planning decisions reveals that the decision d i f f i c u l t i e s stem as much from an inherent misunderstanding of f a i l u re frequencies and consequences as from the problems of considering r isk p robab i l i t i es . QRA w i l l not in i t s e l f abate public concern and i t is for th is reason that e f f o r t must be made to understand local community react ion, and, most importantly the v a r i a b i l i t y in react ions, so that r isk can be e f fec t i ve ly discussed at the local l eve l .

The publ icat ion of the tolerable r isk guidelines used by the HSE w i l l provide information to assist local community decision making. However, paradoxically i t may also present some problems for author i t ies who may wish to go against the HSE's advice as i t seems possible that the guidelines once o f f i c i a l l y published w i l l become more akin to national c r i t e r i a simply because the awareness level of what the statutory safety author i ty regards as acceptable w i l l be increased. As more planning decisions are based on a quant i tat ive assessment and as these increasingly become public information (the introduct ion of a formal Environmental Assessment process, to meet the requirements of EC Direct ive 85/37/EEC, w i l l assist in the l a t t e r ) i t w i l l be easier to compare decisions across au thor i t ies .

Information a v a i l a b i l i t y is only part (a lbe i t a major part) of the answer to the national consideration of land-use planning in re la t ion to major chemical hazards. Many of the decision d i f f i c u l t i e s in Br i ta in arise from the fact that we are t ry ing to add-on a control system to a well developed urban inf rast ructure with long-established hazardous industry. Certainly i t has been important to strengthen land-use planning powers to ensure that the s i t i ng of a l l new major hazard development and of development in the v i c i n i t y can be cont ro l led. Local communities have largely been dealing with land-use planning for hazards on an 'ad hoc' basis as the need

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for development has ar isen. Decisions on individual developments quickly set a precedent for future development. The HSE is now providing considerable input to local plans in re la t ion to development in the v i c i n i t y of hazards, ident i fy ing types of development which would be unacceptable and acceptable in specif ic locat ions. I t has not produced any national guidelines for the s i t i ng of new hazards and nor has the Department of the Environment. Whilst there is current ly l i t t l e pressure for the s i t i ng of new hazards on greenfield s i t es , the avoidance of future problems in local decisions on s i t i ng can only be through long-term planning.

Certainly the B r i t i sh experience provides some lessons for countries developing a hazard control system. The idea of the 'chemical township' planned and promoted to house new and relocated hazardous industry on remote s i tes (33) is a t t rac t i ve as long as the 'remoteness' of the township can be maintained through str ingent land-use planning. I t is important to devise long-term pol ic ies (20 years minimum) for the s i t i ng of hazardous industry and for development in the v i c i n i t y . I t is very important to control development in the v i c i n i t y of s i tes in a way that avoids b l igh t ing of valuable ( in price and amenity) land and does not hamper the development of a balanced community in f ras t ruc tu re , and, ye t , adequately protects sensit ive populations. New development sets a precedent for fur ther development which might become a l l the more d i f f i c u l t to refuse without arousing public concern or undermining economic and social cohesion. I t is important to be able to provide f inancial incentives for the relocation of badly si ted industry where the residual r isks generated by a s i te are unacceptable, and have a f i nanc ia l l y and soc ia l ly negative e f fec t on the growth of an area.

In Br i ta in the major hazard control system is a t r i p a r t i t e system dependent on the industry, the HSE, and the local au thor i t ies . ACNH considered that an e f fec t ive control system must command the confidence of industry, the regulatory au thor i t i es , local author i t ies and the publ ic ; i t must allow for the democratic expression of public opinion; must minimize the areas of disagreement between the various par t ies ; and must be robust - i . e . measures should complement and support each other rather than placing excessive reliance on a single item. In terms of local decisions on r isk there is a rel iance on the technical advice of the HSE. Whilst there has occasionally been concern about the dual role of the HSE as enforcing author i ty and also adviser, on the whole the independence of the technical adviser from local economic and social decision-making is valued. Certainly allowing for the d i rect involvement of local communities in hazard decisions is an important message for developing countr ies.

CONCLUSION

The chemical industry is under close public scrut iny. Major accidents could threaten the industry 's freedom to operate. Led pr imar i ly by the media the public can react strongly against the industry. The industry must be seen to operate safe ly , and f u l l on-si te and land-use planning control powers must be available and exercised. Reactions to the industry, and most importantly the v a r i a b i l i t y of react ion, must be understood. Ef fect ive ways of assessing and publ ic ly discussing r isk must be pos i t i ve ly explored. Industry w i l l benefi t from understanding the concerns of i t s local population and keeping i t informed of i t s a c t i v i t i e s . QRA has become an important element of s i t i ng decisions involving hazard. In Br i ta in the pub l ica t ion, by the HSE, of guidelines on tolerable r isk c r i t e r i a for major hazards should help to enhance the effectiveness of such decisions.

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4. Health and Safety Commission, 1976, "Advisory Committee on Major Hazards First Report", 1979 "Second Report", 1983 "Third Report", HMSO, London, England

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6. Health and Safety Executive, 1985, "Guide to the Control of Industrial Major Accident Hazard Regulations", HMSO, London, England

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14. Green, C.H., 1979, Risk : Beliefs and Attitudes in Regard to Major Hazards.In "The Implications of Large Scale Petrochemical Development", Dept.of Town and Regional Planning, University of Dundee, Scotland

15. Lee, T.R., 1981, Proc. the Royal Soc.London, A376, 5-16

16. Petts, J., 1985, "The Canvey Public Inquiries 1975-1982: Hazard and Risk Issues", Dept. of Chemical Engineering, Loughborough University, England, Working Paper MHC/85/1

17. Macgill, S.M., 1982, "Decision Case Study, United Kingdom Mossmorran-Braefoot Bay",IIASA, Laxenburg, Austria, Report CP-82-40

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28. Ale, B.J.M., Van Nierop, D., and Seaman, M., 1987, "Safeti Zoning Around a Major Industr ia l Complex in the Netherlands", Conference Proceedings "World Conference on Chemical Accidents", CEP Consultants L t d . , Edinburgh, Scotland

29. Lans, H.J.D., 1987, " Ident i fy ing and Evaluating Risks", IFHP-IULA Symposium Proceedings "Prevention and Containment of Large-scale Industr ia l Accidents", International Federation for Housing and Planning, The Hague, Netherlands

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31. Royal Society, 1983, "Risk Assessment A Study Group Report", The Royal Society, London, England

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Major hazards control: the local community and risk decisions and loss... · MAJOR HAZARD CONTROL : THE LOCAL COMMUNITY AND RISK DECISIONS ... have got to be assessed and discussed