Many employers believe that regular inspections of production machines in line with PUWER is all that is necessary to meet legal obligations in respect to safety. If the machine incorporates electro-sensitive protection equipment that may not be true, says Gary Trewhitt of Safety Systems Technology

The Provision and Use of Work Equipment Regulations 1998 (PUWER) are wide ranging and most manufacturers have become used to implementing their provisions. In particular, responsible organisations are careful to ensure that their machines are inspected in line with Section 6 which requires that if they are exposed to conditions that may lead to deterioration, the inspections must be repeated ‘at suitable intervals’. As such, all machines must be regularly inspected.

It would seem reasonable to assume that provided these PUWER inspections are conducted conscientiously and at appropriate intervals, employers have done all that is needed to ensure that their production machinery is safe. However, if that machinery incorporates electro-sensitive protective equipment (ESPE), this may not be the case. ESPE which includes light guards and laser scanners is used increasingly on modern machines where it often takes the place of traditional guarding. Because of its growing popularity and the need to ensure that it is properly used and maintained, the Health and Safety Executive (HSE) has published guidance note HSG180 Application of electro-sensitive equipment using light curtains and light beam devices to machinery.

This document which can be downloaded ( free of charge is provided for guidance only. Nevertheless, because the use of ESPE is almost always safety-related, any employer who chooses to disregard HSG180 should be very sure that they could justify their decision if they are called upon to do so – quite possibly in a court of law. The section of HSG180 that deals with inspection and refers directly to Regulation 6 of PUWER includes a requirement for inspections to be conducted on a regular basis.

If it stopped there, regular PUWER inspections would comply with the recommendations, but paragraph 118 states: ‘inspection and testing is required where the safe operation (of the ESPE) is critically dependent on its condition in use and deterioration would lead to a significant risk to the operator or other worker.

‘If this is the case, then installations using ESPE should be inspected at suitable intervals.’

What is a suitable interval

This raises the question: what constitutes a suitable interval? Paragraph 124 of HSG180 states: ‘the recommended maximum period between each periodic inspection and test is six months for type 4 ESPE and twelve months for type 2 ESPE, but this will depend on the equipment it is fitted to and the risk as a whole.’

The ‘types’ of ESPE referred to are defined in IEC 61496-1 Safety of machinery, Electro-sensitive protective equipment; Part 1: General requirements and tests. Type 2 ESPE has a means of periodic test to reveal a failure to danger, while type 4 will not fail to danger for a single fault and is resistant to an accumulation of single faults.

The frequency of periodic testing required for ESPE depends on multiple factors and a six-month interval will apply in many cases. There is no simple answer to the question of how often periodic PUWER assessments should be carried out but there are very few cases where the interval between assessments is as short as six months. The norm seems to be annually which in many cases will not be sufficiently often to meet the recommendations of HSG180 for ESPE installed on the machine.

Skillful evaluation

It is possible that inspection of ESPE will need to be treated as a separate task and not simply as part of the routine PUWER assessments. However, HSG180 raises the issue of the competence of the person performing the inspection. There are many factors that have to be carefully and skilfully evaluated. These include inspecting the positioning of the equipment to make sure that it is the correct distance from the danger zone, ensuring that suitable safeguards are in place to prevent access to the danger zone from directions not covered by the ESPE; testing the overall response time, detection capability, the stopping performance monitor if one is fitted and the primary machine control elements to ensure correct functionality.

Once the ESPE inspection has been completed it must be documented so that evidence can be produced if required to verify that the appropriate inspection regime has been followed.

Tailored test services

When all of these factors are taken into account, it is apparent that there are likely to be many companies that have neither the in-house expertise nor the capacity to perform these additional ESPE assessments. Safety Systems Technology offers a standalone ESPE periodic inspection and test services that can be tailored to meet the precise needs of individual sites.

If correctly applied ESPE can provide levels of safety at least as good as those offered by more conventional guarding and protection techniques.

For it to dependably fulfil its purpose it must be regularly inspected and tested as recommended in HSG180 – simply relying on routine PUWER inspections is not enough.