Introduction to EN 397

Written by Andrew Wood

16 April 2019

Here at Centurion, we believe that the standards that govern head protection (EN 397), written in 1995, and adopted from ISO3873 in 1977, could do more to meet the protection requirements for the modern working environment (available materials and methods have changed significantly).

EN 397 is the European Standard that specifies physical and performance requirements (including testing) for industrial safety helmets. It comprises of mandatory and optional tests:

Mandatory Tests:

  • Shock Absorption Test – the 5kg rounded striker is dropped on the crown of the helmet from 1m. The force transmitted to the head form cannot exceed 5000N (5KN).
  • Resistance to Penetration Test – 3kg pointed striker dropped on the crown region, striker not allowed to contact the head form.
  • Resistance to Flame Test – when exposed to a flame for 10 seconds and then removed, the shell must not set alight or self-extinguish within 5 seconds.
  • Markings – Every helmet which complies to the standard must have the following information moulded or impressed into the shell somewhere visible:
  1. Number of the European Standard (in this case EN 397)
  2. Name or identification mark of the manufacturer
  3. Year & quarter of manufacture (date stamp)
  4. Type of helmet (manufacturers designation): this should be marked on both the shell & harness
  5. Size or size range (in cm), marked on both the helmet & harness
  6. Shell material abbreviation (e.g. ABS, HDPE)

We encourage the end customers we work with to consider their specification beyond the EN 397 standard written so many years ago. We also believe that facilities and health and safety executives should consider adding the following to their purchase specification:

BSIF Registered Safety Supplier Scheme (RSSS): Every RSSS member is independently audited every single year. Products are subjected to random testing for performance and compliance to claimed standards. RSSS members commit to their customer-facing employees being trained in the Safe Supply Accreditation programme to ensure competence in PPE and Health & Safety. Membership of the scheme involves more than testing and training. It includes a shared commitment to advocating the scheme’s benefits to other health and safety providers.

Kitemark: The Kitemark is an unrivalled stamp of quality. From its creation in 1903, it is now recognised globally as a business super brand – whose independent testing has become the benchmark in product quality and compliance. The Kitemark, in our view, is so valuable for two reasons.Firstly, unlike the CE mark which certifies businesses to minimum legal requirements, the Kitemark sets standards of compliance that go far beyond the legal minimum. We believe in always striving for what is best, not what is simply permitted. And we believe the Kitemark is a fitting testament to this ethos.

Secondly, much of the Kitemark’s rigour is rooted in its insistence on regular testing and re-testing businesses against its exacting standards. And in its constant monitoring and review of those standards to ensure they remain resolutely fit for the world they operate in. So, the Kitemark isn’t proof that a business has ‘passed a test’ – it’s proof that a business is constantly maintaining the highest of standards – a feat that demonstrates a deeper commitment to going above and beyond. Our job is to keep people safe. So, our view will always remain black and white. There can be no “that’ll do” when lives are at risk. Acceptable isn’t ever acceptable when we know we can push for better. And meeting standards will never be enough when we could be setting standards.

Chinstraps: At Centurion, we believe that chinstraps should be mandatory and that chinstraps help improve site safety. This is paramount when working in an environment where a helmet could fall on someone below, this is particularly important and often referred to “working at height”. If a wearer’s helmet isn’t securely fitted, upon impact the protection levels will be comprised. If a wearer were to be struck by an object there is a chance that the impact could knock the helmet off their head, this would not happen if you were wearing a chinstrap and would provide protection against any subsequent impacts.

Mandatory Chinstrap Anchorage Test – An artificial jaw is released at a force no less than 150N and no more than 250N, due to the failure of the anchorage(s). This test is mandatory if the helmet has a fitted chinstrap.

Optional Tests:

  1. Very low temperature – Optional pre-conditioning temperature of -20°C or -30°C for the shock absorption and resistance to penetration tests. At Centurion, our complete ABS helmet range has approvals to -40°C, we exceed standards as a sign of our commitment to keeping safe safer. We always recommend for users to add this into any helmet specification.
  2. Very high temperature – Optional pre-conditioning temperature of +150°C for the shock absorption and resistance to penetration tests. This test is for environments such as foundries, giving workers the confidence that our products continue to perform in the harshest of conditions. We recommend users to include this into specifications for certain environments.
  3. Electrical Properties – Also known as the ‘440 V AC’ test. 3 individual tests are performed and a maximum leakage current of 1.2 milliamps is allowed. Helmets that are conductive or have vents cannot pass these tests. The purpose of this test is to see how well the helmet protects the wearer from accidental contact with electrical conductors at voltages up to 440V a.c. We recommend users to include this into specifications for certain environments.
  4. Lateral Deformation – When exposed to steadily increasing compressive force of 430N the helmets deformation must be no more than 40mm. Our complete ABS helmet range is all approved to LD, this test is further proof that our integrated systems are designed to provide total head protection. We always recommend for users to add this into any helmet specification.
  5. Molten Metal Splash – Motel metal (heated to 1400°C) is poured on to the helmet, the helmet must not be penetrated by more than 10mm, and any flames must self-extinguish within 5 seconds. We recommend users to include this into specifications for certain environments.

We test our products to levels above and beyond the norm, giving workers the confidence to deliver their best.