Getting your head around helmet standards

Head protection is a necessity on site. Safety helmets help to prevent head and brain injuries by absorbing impact energy and resisting penetration by falling or ejected objects. Some helmets protect against other hazards including molten metal and electrical risks. Ensuring the best level of protection means finding the right helmet for the task, hazard and wearer.

Safety helmets are designed to meet one or more standards which set out design, performance and testing requirements for a specific type of product. Two of the main standards are EN 397, Industrial Safety Helmets and EN 12492, Helmets for Mountaineers.

Helmet standards

EN 397 helmets are traditionally used in construction, manufacturing and other industrial applications. The standard was first published over 60 years ago, as BS2826, setting out requirements for shock absorption and penetration protection against objects impacting the top of the helmet. Industrial safety helmets usually comprise an outer hard plastic shell and internal harness. Ventilation holes and chinstraps are optional. 

While these helmets have been widely used in the past, the impact protection offered under EN 397 can be limited in some applications. Industrial safety helmets are not required to offer shock absorption to the sides – the current standard includes a test for lateral rigidity, but impact testing is only carried out on the crown. The level of crown impact protection is also exceeded by other standards.

EN 397 requires helmets to be tested for shock absorption on the crown with an impact energy of 50J. EN 12492 however requires testing for crown shock absorption at 100J, doubling that of the industrial standard. Penetration resistance is tested at the same level as an industrial helmet. In addition, EN 12492 includes shock absorption testing on the side, front and rear at 25J. 

The EN 12492 standard is titled Mountaineering equipment - Helmets for mountaineers though these products are also used in some work at height applications. They differ from EN 397 helmets in a few major ways. EN 12492 helmets must be ventilated and include a mandatory chinstrap.

As EN 12492 chinstraps are intended for use in climbing applications, they function in a different way to those designed for industrial head protection. The chinstrap on a mountaineering-style helmet forms an integral part of the retention system which is tested to ensure the strap does not break or elongate when a force of 500N is applied. This helps to keep the helmet secure in case of repeated impacts from swinging or multiple falling objects.

In an industrial setting, however, this may create a hazard. Optional chinstraps for EN 397 helmets are tested to ensure they release under a force of 150-250N. This allows the strap to release if caught up or snagged creating danger for the user to increase safety when working around moving machinery or equipment.

Applications

Hazard and risk assessments inform selection for individual tasks but looking at the type and level of protection offered by helmets that meet each standard can indicate some general uses. 

EN 12492 helmets are used in a range of working at height applications carried out with harnesses and lifelines, as well as mobile platform work. They are often specified for fall risk areas due to the shock absorption performance and retention system action which maximises protection in the event of a fall. Mountaineering helmets are used in the energy industry, offering increased stability as well as comfort benefits from ventilation and increased field of vision with a reduced peak size. 

In industries such as construction, utilities and manufacturing, EN 397 helmets have been the conventional choice. Working mainly at ground level with a primary risk of objects falling from above means the helmet can offer adequate protection, and the chinstrap release function can be more suitable if working around moving machinery. 

Recently EN 12492 helmets are used more widely in these industries. Driven by a need for increased impact protection, mountaineering helmets are being selected for more tasks where they can be used safely. Providing shock absorption to the sides, front and rear of the helmet protects the wearer against impacts from multiple directions, and not just objects falling from above. The level of crown impact protection is also significantly higher than that provided by an EN 397 helmet. 

Key differences

It is important to keep in mind that, despite needs for increased impact protection, EN 12492 helmets may not be appropriate due to the retention system. Some tasks require an EN 397 compliant helmet for environments where the head protection could become caught or snagged and create danger for the wearer. EN 397 offers optional requirements that are not covered by EN 12492, such as molten metal resistance, and 440V electrical insulation for non-vented helmets.

Applying EN 50365 introduces another complication. This standard is applicable to electrically insulating helmets for use on low voltage installations with 1000V electrical insulation. However in order to be certified to EN 50365 the helmet must fulfil the requirements of EN 397.

With essential performance features split across multiple standards, it can be difficult to find a helmet that offers the required level of protection. In some cases two helmets are specified for the same operative, in order to achieve the appropriate protection for different tasks.

Multi-standard protection

Until the standards are updated, innovative design is necessary to resolve these conflicts and deliver products that meet the needs of the wearer. Helmets certified to EN 397 that offer a higher level of shock absorption can be a good choice for applications with increased impact risks and a need for the chinstrap to release in case of being caught or snagged. Following developments in chinstrap technology, some helmets are now fully certified to both standards. These products can offer EN 12492 level impact protection and retention system performance along with the additional options applicable under EN 397 and 1000V electrical insulation. Choosing a helmet that meets all the relevant standards and offers the correct level of protection is crucial to make sure wearers are safe on site. 

Louise Charlton is technical copywriter at JSP. For more information visit www.jspsafety.com.