Risk Assessment

The Story

A recent discussion on the scaffolders forum has highlighted the fact that not everyone in the scaffolding industry is aware of what constitutes a designer's risk assessment as it relates to scaffolds and scaffold design. In fact, even those who should be carrying out scaffold design risk assessments are not always fully aware of the extent of their responsibilities!

What is a Design Risk Assessment?

A Design Risk Assessment is a formal record of the process that every designer should go through as they produce a scaffold design.

The designer should be making assessments of the hazards involved/surrounding/associated with the scaffold they are designing and forming the design in such a way that eliminates the risk associated with each hazard. Where risk cannot be eliminated, control measures should be suggested and introduced as part of the design that will control the hazard and reduce the risk to an acceptable level. The remaining hazards that cannot be totally eliminated through effective design are called 'residual hazards'.

Of course there are various ways of going about the hazard analysis and mitigation process (e.g. comparative, quantitative, qualitative etc.), some that are better suited to the particular requirements of scaffold design than others. It is down to the individual scaffold designer to choose the method and process that is most appropriate for their work. The basic principles are the same regardless of method though, and are identified by the UK Health and Safety Executive as the "Five steps to risk assessment:"

  1. Identify the hazards
  2. Decide who might be harmed and how
  3. Evaluate the risks and decide on precaution
  4. Record your findings and implement them
  5. Review your assessment and update if necessary

Who Carries Out a Design Risk Assessment?

The following is an extract from BS 5975 which covers the Procedural Control of Temporary Works (including all scaffolding):

"The CDM Regulations require that any designer provides adequate information about any significant risk associated with the design, e.g. a list of residual hazards. There is also a requirement to co-ordinate the work with that of others in order to improve the way in which risks are managed and controlled. This may include the use of suggested construction sequences. For complex schemes it is recommended that the temporary works designer brief the site team on the key elements and hazards identified during the design process."

Some designers use a generic note on their drawings for identification of residual hazards with hazard symbols next to the relevant drawing notes. This approach is perfectly acceptable as a means of communicating residual hazards via the design drawing. It does not however provide a record of the process of hazard identification (and elimination) that every design engineer must go through when completing a scaffold design. So, although the legal obligations may technically have been met by conveying the residual hazard information, there is no evidence that the basic procedure outlined by the HSE's "Five steps". In other words, although steps 1,2,3 and 5 may well have been followed, the fact that step 4 "Record your findings and implement them" is only partially complete means there is no obvious way to find out whether the rest have been done at all (and if so, whether they have been competently carried out).

Scaffold Design Risk Assessment at 48.3

To put all of this more simply, any designer (of any structure, not just in temporary works design) should be providing evidence that they have carried out the hazard identification / elimination / communication process broadly outlined above, and the easiest way of doing that is to complete a formal design risk assessment as part of the design documentation they submit. Here at 48.3, we do this for every scaffold design: the design risk assessment forms an essential part of the design package you receive for every job. It integrates with the drawings so that residual hazards are identified and the control measures we suggest can be implemented. This risk assessment is then re-evaluated upon any subsequent design revisions, thus complying with all 5 steps highlighted by the HSE.

It is up to individual designers and design companies to decide how to meet their legal obligations regarding risks (and to show that they have done so), but we have yet to see a better approach than doing a formal scaffold design risk assessment every time, on every job.