NITRAS SAFETY | EN 397

WHY HEADGEAR IS INVISIBLE

At construction sites, in production halls, or during technical maintenance work, hazards from above are not the exception, but rather the norm: falling parts, swinging tools, unexpected shocks. A functional industrial safety helmet makes the crucial difference between a safe workday and a serious head injury.

This is where the EN 397 standard comes in. It defines binding requirements for industrial safety helmets used in commercial applications. The goal is to protect the wearer from falling objects and resulting injuries such as skull fractures or concussions—and to do so under standardized conditions. It also regulates optional performance features, such as extreme temperatures, electrical voltage, or metal splashes, to make the helmet flexible and adaptable to different areas of use.

EN 397 OVERVIEW

EN 397 sets out the mandatory physical, mechanical, and functional requirements, as well as the corresponding test methods, for industrial safety helmets. It is aimed at helmets for general commercial use, with the goal of ensuring reliable protection of the head from typical dangers such as falling objects, bumps, and penetration in everyday work.

The binding minimum requirements at a glance:

Test feature	Description of risk	Requirements according to EN 397
Shock absorption	Impact energy from falling objects	Max. force transmission ≤ 5 kN at a fall energy of 50 J
Penetration resistance	Penetration by pointed or sharp objects	No contact when a test body (3 kg, 1 m height) falls
Flame resistance	Short-term contact with an open flame	Helmet may burn for a maximum of 5 seconds after contact with flame
Mouthpiece strap strength	Uncontrolled release or tearing of the retention system	Must tear between 15 daN and 25 daN
Temperature resistance	Operation in hot or cold work environments	Operating range: -10°C to 50°C

Note: These requirements apply to helmets for general industrial use. Additionally, optional performance features can be tested and indicated, such as for extreme temperatures, electrical risks, or lateral deformation. These additional tests are voluntary and are explicitly marked on the helmet by the manufacturer.

OPTIONAL REQUIRED PERFORMANCE FEATURES

The following features can be optionally certified, depending on the application requirements:

Additional feature	Meaning
-20C° or -30 °C / +150 °C	protection against extreme temperatures, e.g. in extreme heat or cold
440 V AC	Short-term contact with electrical voltage
LD (Lateral Deformation)	Lateral deformation due to pressure or impact
MM (Molten Metal)	Protection from small splashes of liquid metal (e.g., casting)

Important: These optional performance features are not standard on every industrial safety helmet, but must be specifically selected and clearly marked on the product (e.g., by pictograms or abbreviations such as "-30 °C", "440 V AC", "LD").

Our tip: Always consider the specific environmental influences and requirements of the activity when making your selection. Only in this way can it be ensured that the helmet provides the necessary additional protection.

THE IDENTIFICATION SYSTEM

Every protective helmet certified according to EN 397 must be permanently and clearly marked. This marking is not only a source of information, but also a prerequisite for lawful use under the PPE Regulation.

The following information is mandatory:

1. Standard designation (EN 397)
2. Manufacturer name and model designation
3. Production year and month
4. Size range (e.g., 52–64 cm head circumference)
5. Pictograms/Abbreviations for optional security features

Only helmets with complete and legible marking are considered compliant with the standard and may be sold or used.Missing or illegible markings will result in exclusion from the PSA test and may also be relevant for liability in an emergency.

Safety starts with the right helmet

Industrial safety helmets are an essential part of PPE, especially where there is a risk of head injuries. EN 397 provides clear technical guidance: it ensures that tested helmets can not only absorb impacts but also withstand flames, cold, or electricity, depending on the model.

Important for practice: Not every helmet automatically fulfills all protective functions. Check the markings, operating conditions, and additional options, and choose the helmet that matches the risk assessment. Only then can the protective effect be ensured in the event of an emergency.