Informa Markets

Author Bio ▼

Safety and Health Practitioner (SHP) is first for independent health and safety news.
June 13, 2012

Get the SHP newsletter

Daily health and safety news, job alerts and resources

Manufacturing – machinery safety – Be on your guard

Given the number of prosecutions being taken against companies for machine-guarding offences, it is obvious that many duty-holders are unaware of the law in this area, and particularly the changes brought in by the new Machinery Safety Directive. Paul Laidler discusses the main requirements of the Directive and suggests how best to tackle machine-guard safety in the workplace.

It might sound like the infamous ‘common sense’ to say that guards play a vital role in ensuring that machines are safe to operate, but they are often treated surprisingly casually and are the cause of many severe injuries that could have been prevented had the appropriate guards been used.

To try to tackle this problem in industry, the updated Machinery Safety Directive (2006/42/EC)1 came into force in December 2009, introducing a range of new requirements for guards. While previous incarnations of the Directive referred only to ‘safety components’, the latest edition specifically lists what those safety components are, one of which is guarding.

However, there are still far too many companies being prosecuted for flouting machine-guarding legislation – in the first five months of this year alone, five serious cases were reported in SHP.

With most employers, there is no malicious intent on their part; they are simply unaware of what they are required to do, and that the legislation has changed. So what are those requirements, what should businesses expect from their machinery suppliers, and how can guard safety best be tackled in the workplace?

A ‘new approach’ directive

The Machinery Directive must now be observed by anyone supplying a machine in the European Union. To carry a CE marking a product must comply with all applicable EU standards, many of which apply specifically to guards. A few examples are:

  • EN 953: ‘Safety of Machinery – Guards – General Requirements’;
  • EN ISO 13857: ‘Safety of Machinery – Safety distances to prevent hazard zones being reached by upper and lower limbs’; and
  • EN 349: ‘Safety of Machinery – Minimum gaps to avoid crushing of parts of the human body’.

Know the essentials

For those who are tasked with managing workplace safety, the changes that are likely to be of particular interest are those concerning machines’ essential health and safety requirements (EHSRs). These cover aspects such as guarding and other safety features that manufacturers must build into their machines before they can carry the CE marking that shows they conform to EU requirements.

Guarding is specifically referred to in the EHSRs. Section 1.4.2.1 of the new Machiney Safety Directive requires that all fixed guards must be removable only with the aid of tools. While a similar requirement was contained in the previous Machinery Directive, the fixing systems must now remain attached to the guards when the guards are removed. This means that ordinary machine screws and bolts can no longer be used as a means of attaching guards unless provision is made for the screws or bolts to be held captive when the guard is removed.

Guards must also now protect against the ejection of falling materials and objects. For example, if a grinding wheel explodes, can the guarding contain that explosion?

One of the other requirements of Section 1.4.2.1 is potentially even more challenging. It states that guards should be incapable of remaining in position when their fixings have been removed. This means some careful thinking will be required to ensure, for example, that hinged guards open automatically when they are released, and that guards on the top of machines are not retained in position by gravity when their fixings have been removed.

While a raft of standards underpin the new Directive, the most relevant to guarding is BS EN 1088: ‘Safety of machinery – Interlocking devices associated with guards – Principles for design and selection’. Interlocks prevent a user from making unsafe actions. For example, a guard may be interlocked to prevent machine operation when a guard is removed.

One of the key statements to take into account when assessing the safety of machinery in the workplace is in Section 5.7 of BS EN 1088: “If the specification of the safety interlocking device is such that it is possible to defeat the safety function solely by a reasonably foreseeable action at the interlocking device itself, and if the device itself is to be relied upon to prevent defeat, it should provide measures to minimise the possibility of defeat.”

Exactly what constitutes ‘a reasonably foreseeable action’ that could defeat the interlock is explained as an intentional attempt to defeat the interlock either manually, or with the aid of some readily available object. In other words, operators not using machinery correctly, or choosing to take short cuts during production.

The standard goes on to explain that the extent to which these measures are applied should be decided on the basis of a risk assessment, and it’s clear that interlock systems used in the workplace need to be carefully considered and designed.

If a company can prove it took all reasonable steps to ensure that an interlocking device could not be defeated, then it becomes a ‘deliberate misuse’ by the employee, rather than the fault of the employer. It’s difficult to account for idiocy, but companies must ensure that they have thoroughly considered any possible misuse.

The standard goes further by stating that “defeat in a reasonably foreseeable manner” includes the removal of actuators and switches with the intention of disabling an interlocking device. But this begs the question: how is it possible to fix switches and actuators in such a way that they can’t be removed with normal tools?

At first sight, the options are limited to the likes of high-strength adhesives, welding, and special anti-tamper fixing devices, such as screws with one-way heads. If such fixings are applied, however, what happens when it is necessary to remove one of these devices for legitimate (e.g. maintenance) reasons? The answer is almost certainly that you can’t, as the only available methods of removal are likely to result in the destruction of the interlock.

This may be an unintended consequence of the standard, but destroying a few interlocking devices should be considered a small price to pay for enhancing operator safety and avoiding health and safety prosecutions.

While welding or glueing can be used to fool-proof any attempts to tamper with interlocking devices, BS EN 1088 does not recommend them as methods. Instead, the standard suggests alternative measures to guard against interlocks being defeated, including regular cyclic checking of the interlock device by some form of safety-control system. Such checks would mean the requirements for ensuring that the interlocking device itself cannot be defeated could be relaxed.

Above all, however, BS EN 1088 encourages companies to recognise the reasons why operators attempt to defeat interlocks in the first place, and to address these in the machine design. Most often, operators try to defeat an interlock to improve productivity. The real question here is whether the machine design can be modified so that the guard no longer inhibits productivity, which, in turn, means the operator will not be tempted to defeat the interlock.

It’s what you know, not who you know

It is obvious from the number of prosecutions relating to machine guarding that there is still a severe lack of knowledge of the Machinery Safety Directive and accompanying standards. The main problem is not new machinery being brought into the workplace, but existing machines. If, for example, maintenance personnel are not fully aware of the requirements and a guard is damaged, they may attempt to fix it incorrectly themselves, or send it to a fabricator who is not a machine expert and therefore not up to date with the legislation.

If a fabricator is asked to manufacture a new guard to fit on to an existing machine, then the guard also requires CE marking, as it is considered part of the machine. This is where many fall foul of the law, as they are simply not aware that the same rules apply to the guard. The new guard must go through the entire CE marking process, including risk assessment and compilation of a technical construction file (the Directive states what this must contain, including calculations, drawings and test results), before the fabricator can make a declaration of conformity for CE marking.

A ‘make do and mend’ attitude could land a business in hot water, particularly as regulation 10 of the Provision and Use of Work Equipment Regulations 1998 (PUWER) requires that an employer must ensure that any equipment subject to European directives complies with all applicable EHSRs of those directives. This includes ensuring that the manufacturers from which they buy machinery have CE marked their products correctly and followed the right procedures.

Conclusion

Although the requirements of the Machinery Safety Directive may seem daunting they must nevertheless be complied with by businesses that use machinery. The HSE is obviously more than willing to prosecute firms whose failure to comply results in an employee being severely injured. Many duty-holders use the excuse that they are not the manufacturers of machinery and therefore must rely on their suppliers knowing what they are doing.

However, ignorance is no defence and failing to comply with the Machinery Safety Directive and/or PUWER, whether knowingly or unknowingly, can have serious and far-reaching consequences for both employers and their employees. 

Reference
1    To find out more about the Machinery Safety Directive, visit www.hse.gov.uk/work-equipment-machinery/new-machinery.htm

Paul Laidler works for TÜV SÜD Product Service.

The Safety Conversation Podcast: Listen now!

The Safety Conversation with SHP (previously the Safety and Health Podcast) aims to bring you the latest news, insights and legislation updates in the form of interviews, discussions and panel debates from leading figures within the profession.

Find us on Apple Podcasts, Spotify and Google Podcasts, subscribe and join the conversation today!

Related Topics

Subscribe
Notify of
guest

1 Comment
Oldest
Newest Most Voted
Inline Feedbacks
View all comments
Phadley
Phadley
11 years ago

Generally a good article.
However 1.4.2.1 is misquoted. It actually states “WHERE POSSIBLE, guards must be incapable of remaining in place without their fixing”. My interpretation is that this allows a more sensible approach to be taken to guards mounted horizontally so they don’t fall through a machine, or on to someone beneath, when their fixings are removed.