EHJ May 2002, pages 140-142 Gerry Warren reports on the complex health and safety issues highlighted in a recent case, settled before the High Court, concerning the replacement of a pitched roof believed to contain asbestos

The key issues of the case in question - Centura Foods Ltd v Dependable Homes Ltd - relate to the discharge of the general duties of employers, and controllers, of premises used as workplaces for the management of risk, with respect to the provision of reasonably safe work places in reasonably foreseeable circumstances.

On this basis, assessment of any occupational health or safety case becomes a matter of assessing that which an employer, or conductor of the undertaking, can reasonably be expected to know of the risks of identified hazards; whether he knows it; and how he has acted on that knowledge. Then, assessing what measures can be implemented to avoid "avoidable" risks. In this particular case, by preventing "preventable exposure" to asbestos.

Thereafter, the question is "what measures can be implemented to manage residual risks at the lowest level reasonably practicable?" And finally, whether they are implemented, their effectiveness monitored and whether the review process is in place.

THE FACTS OF THE CASE

According to the dilapidation surveyor, the pitched roof of the premises in question was believed to: "contain asbestos, therefore great care should be recognised during any work programme. Due to its fragile nature, caution significant risk of falling, even with trained personnel. This roof cannot therefore be maintained safely. Any work undertaken would be imprudent and would certainly shorten the life-span."

A subsequent asbestos survey reported the presence of asbestos insulation board within the building. In addition, a range of asbestos cement products, described as in "fair" condition, were present in the roof coverings, rain water goods, barge boards and vents etc. The roof of the premises was of two spans - one of 109m by 21m, the other 79m by 21m - and had, approximately, a five degree pitch. The building contained a working distribution warehouse, with some 60 employees. Subsequent inspections revealed defective smoke ventilators and roof lights installed in the roof, cracking, weathering and softening of the surface, and a number of existing small repairs to the asbestos cement materials and corrosion to fixings.

THE DISPUTE

Given the above, and advised by lawyers that repair would include renewal when the element under consideration has reached the end of its useful life, the lessor - the defendant in the action - required the lessee to remove the asbestos and renew the roof in accordance with the terms of the lease. The claimant - the lessee - sought a declaration as to the works required to the roof of the premises, comprising an area of approximately 3,800 m2, to comply with these repairing covenants.

An over roof, leaving asbestos cement materials in situ, was proposed by the claimant as an alternative to a new roof. Later, localised repairs to the defective asbestos cement sheets, and other elements of the roof structure in disrepair, was proposed. Finally, this action, plus coating the asbestos cement externally with a sealant, was put forward.

THE RISK MANAGEMENT ISSUES

The brief relating to the management of risk was to consider the condition of the asbestos containing materials (ACMs) used in the construction of the roof and the relevance and effect of that condition with regard to the repair of the roof.

As an environmental health practitioner, the author was engaged to advise as to the management of exposure to risks of asbestos in a workplace for a number of proposals relating primarily to these ACMs in the roof structure:

• re-roof, using non-asbestos containing materials;
• over roof;
• localised repair; or
• localised repair and coating.

It appeared to be a matter of exposure to reasonably foreseeable and significant risk and the reasonable means available to avoid or control it. These were potentially capable of causing serious and permanent disability or death.

METHODOLOGY

An assessment methodology was devised, based on the risk assessment provisions of the Management of Health and Safety at Work Regulations 1999 (MHSW). Application of the hierarchy of risk to the key hazards and the systems of work thus allowed questions of reasonable practicability to be assessed by reference to the risks, first, in each case. These in turn were evaluated by reference to costs, in terms of time, trouble and money.

Other requirements, such as co-operation and co-ordination between employers (eg host employer and contractor relationships) provided further bases against which to assess the various courses of action proposed.

The test of reasonable practicability was determined by reference to foreseeable and significant risk, the state of current technical knowledge and the time, trouble and financial costs of implementing preventive or protective measures. Investigation and risk assessment comprised of a forensic audit of available evidence using the trail implied by regulations 3 and 5 of the MHSW, which appear pre-requisite to assessments made under the Control of Asbestos at Work [CAW], Construction Design and Management, or any other regulations made under the Act. It appears difficult to comply with these, if compliance with MHSW is inadequate.

The basis for assessment was drawn primarily from appropriate approved codes of practice, supported where necessary by reference to other published guidance and standards.

THE RISKS

Each option presented a complex set of hazards, principally:

• asbestos (amosite and chrysotile) in asbestos cement and insulation board products;
• construction and workplace health and safety, particularly falls;
• systems of work; and
• provision and use of work equipment.

In addition to the risks presented by undertaking the proposed works, each presented various continuing and residual risks. The condition of the ACMs comprising the roof covering presented, principally, for the construction phases:

• high risk of a fall from a height;
• significant risk in use of work equipment, and (for exposure to asbestos);
• high risk of episodes of high exposure; and
• high risk of episodes of low exposure.

For the workplace the risks were:

• high continuing risk of episodes of high exposure;
• high continuing risk of episodes of low exposure; and
• a number of continuing low risks of low, but significant, exposure over extended periods.

For options in which the ACMs were to be left in-situ, there were also the residual risks at eventual replacement or demolition to be considered, since these merely deferred the need for removal.

For all options, the most significant risk presented by the condition of the ACMs was that of a fall from a height likely to cause personal injury. This was pointed out in the first survey report. It was caused by the brittle nature of the asbestos cement sheets and difficulties in providing safe access. In addition to this, though the probability of realisation of the risks for a single exposure was low, the serious and life threatening potential consequences warranted very high standards of control; comparable to those exercised in respect of other similarly hazardous substances and as reflected by the regulatory regime.

The state of repair of other structural components of the roof was also significant. Roof lights comprising GRP sheets were in poor condition and required attention. The smoke vents installed along the ridges were in disrepair and many were clearly non-functional. All added to the overall risk. In addition to the required outcome of any works to these components (eg under the W(HSW) regulations or fire protection legislation) undertaking these works carried risks in working on the ACMs and of disturbing or damaging them.

EXPOSURE TO ASBESTOS

All forms of asbestos are class 1 carcinogens - there is no such thing as "acceptable" exposure. Thus, it was dangerous to oversimplify the complex of hazards or trivialise the risks implied by any proposed solution to the disrepair. Control limits and action levels do not represent "safe" exposures. These are maximum exposures, acceptable only when the risk cannot be avoided. No preventable (or avoidable) exposure is "acceptable".

SATISFACTORY CONCLUSION

Regulation 4 and the schedule to MHSW provide the tools to ask the question "can the risk be avoided?" If so, is avoiding the risk reasonably practicable? If the answer to either of the above is no, the risk must be evaluated and controlled. In this matter, the answer to the first and second questions was yes. By renewing the roof in its entirety with non-asbestos containing materials, a reasonably practicable solution was found that was in proportion to the overall risk.

This avoided the residual and continuing risks of the alternate options and was a preventive measure, not a protective one. It was not, in itself, a risk free option as no such thing seems to exist. However, an evaluation of the overall risk presented by each proposal indicated it to be the least risky option by a considerable degree.

The question of whether the avoidable risk needed to be controlled (managed) by over roofing, localised repair, encapsulation or any other technique involving leaving the material in situ need not then arise. The occupational health and safety issues came down, in essence, to the basis of assessment found in the principles of prevention to be applied and the conclusion appeared inescapable - exposure to risk could reasonably be avoided.

This seems to be the option required in every case where it is reasonably practicable to avoid risk. In this case, it was the re-roof option. Of course, this was not how the claimant saw things. Because of this, the opposing teams of lawyers and experts were required, up to the morning of the trial, to work their way through the minutiae of the evidence and regulatory and technical requirements at great length and expense. Largely, this seemed due to the claimant's lack, at strategic level, of an adherent overall policy for occupational health and safety.

Thus, on 5 February 2001, two and a half years after the original survey, the claimants finally agreed to avoid the avoidable risk by removal of the ACMs and renewal of the roof.

Gerry Warren, environmental health and safety consultant and lecturer in environmental health, City College, Norwich. For further information Tel: 01733 310547 or e-mail: gerry.warren@virgin.net

Acknowledgement must be given to Michael Brandman, Mike Kilbey, John Mullen, Rachel Glasscock, Edward Cohen and Trevor Leigh for their dedication and hard work on this case.

As the case proceeded, the debate over the HSE's proposals in respect of management of asbestos in buildings progressed independently. In the context of this case, much of this began to seem somewhat superfluous in respect of workplaces, particularly the TUC's recent demand for the legal right for people to be informed of contamination by asbestos.

Employers are required to make a suitable and sufficient assessment of the risks to the health and safety of their employees at work. They are then required to inform employees of the significant findings of that assessment. The process begins with the identification of hazards:

• asbestos is a hazard;
• risk may be low but not trivial or insignificant;
• the risk may be controlled, eg by encapsulation, but unless the asbestos is removed and safely disposed of, the hazard remains.

Also, applying Regulation 4 and the schedule to MHSW to the significant findings of the assessment and making and giving effect to the arrangements required under Regulation 5, allows a best available solution and cost-effective prioritisation to evolve. It also becomes possible to direct available resources to avoiding that risk which may be avoided and reducing residual risk to the lowest level reasonably practicable.