A head for safety

THOUSANDS OF workplace head injuries are sustained each year across Great Britain. Impacts from falling and flying objects, as well as falls from height, can result in a life-changing or even fatal Traumatic Brain Injury (TBI). Stringent safety measures are put in place to protect staff, yet injuries still occur. 

Compliance has improved and helmets are generally worn when they should be. However even with a greater focus on the need for protection, confusion around different types of helmets can leave workers at risk.

EN 397 helmets have long been the popular choice for various applications. More recently, a need for higher energy and side impact protection prompted many companies to opt for EN12492 instead. These two standards have fundamental differences that are vital to understand when selecting a helmet.

EN 397 helmets

EN 397 industrial safety helmets are intended to protect the wearer against objects falling from above. Due to this, impact testing is only carried out on the insert of the helmet. Shock absorption is assessed with a 49 Joule impact on the top of the helmet. Penetration resistance is tested using a conical striker dropped in the same area. 

There are currently no side impact requirements in EN 397. Optional lateral deformation testing assesses the helmet’s ability to resist a force applied on either side, but this is a slow progressive loading designed to assess protection against crushing risks. 

The EN 397 standard also specifies other optional and additional requirements. Tests for molten metal resistance and electrical insulation allow helmets to offer protection against additional hazards.

EN12492 helmets

Where a risk assessment calls for helmets with that call for side impact protection, companies began to adopt EN12492 helmets instead. These helmets incorporate an internal shock absorbing liner and integral 4-point chinstrap. 

EN12492 specifies requirements for mountaineering helmets. As they are intended for use in climbing applications, EN12492 helmets are subjected to more rigorous impact tests. Shock absorption testing in multiple locations around the helmet assesses protection against impacts sustained from swinging. 

The test headform is tilted 60° to the vertical to carry out a 25Joule shock absorption test on the sides, front and rear of the helmet. In addition, crown shock absorption is tested at roughly 98Joule, double the energy required by EN397. Penetration testing is also conducted on the crown, equivalent to EN397 tests.

The increased level of shock absorption may make EN12492 helmets appear the obvious choice, but it is important to consider the task and environment to select head protection according to the risk assessment.

Chinstrap function

With different intended uses, the chinstraps for EN 397 and EN 12492 helmets function in different ways. EN 397 chinstraps are optional. If one is fitted, it must release under 150-250N of force. This is designed to limit the risk of strangulation or injury in case the strap becomes caught on something. 

EN 12492 helmets need to stay on the head in case of repeated impacts from swinging or multiple falling objects in a climbing setting. Chinstraps are therefore mandatory, acting as an integral part of the helmet’s retention system. Testing is carried out to ensure the strap does not break or stretch when a force of 500N is applied. 

Another EN 12492 test makes sure the helmet stays in place if knocked at the front or back. A mass is dropped on the front and rear of the helmet, which must remain secure on the test headform. 

Helmet selection

When selecting a helmet it is important to think about chinstrap function, impact requirements and other protective features needed to keep wearers safe. 

Whilst necessary for safety in a climbing application, an EN 12492 chinstrap could become a hazard in an environment with moving machinery or equipment. The EN 397 standard also includes requirements that are not covered by EN 12492. For molten metal or electrical risks, an industrial helmet may be needed to provide adequate protection.

However an EN 397 helmet is not intended to protect against off-crown impacts. Without EN 12492 shock absorption testing, the wearer could be at risk of injury from impacts to other areas around the helmet. The chinstrap is not designed to stay secure in the event of repeated impacts and could leave the wearer unprotected if the helmet is knocked off the head. 

EN 12492 helmets on the other hand absorb shocks to the top, sides, front and rear. Testing is carried out to ensure the chinstrap stays secure under force, and the helmet remains in place if knocked at the front or rear, maximising protection during a fall. 

To choose the right helmet, consider how and where it will be used. It is important to carry out the risk assessment and assess the hazards and how the helmet needs to function to protect the wearer. The EN 397 and EN 12492 standards have key differences that optimise protection in their respective applications but could present a hazard if used in the wrong setting. In addition to selecting the correct level of impact protection, it is crucial to make sure the chinstrap is appropriate for the environment. The selected helmet must provide the correct type of protection to keep wearers safe on site. 

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

Reference

1 RIDDOR reported fatal and non-fatal injuries by site of injury (RIDSITE), 2014/15-2022/23