There are 7 factors that determine whether a helmet is safe, specifically for its user. Here you’ll find out which factors there are and why they make a helmet safe for you (and you alone).


“Homologation” is an accreditation issued by an official body declaring the helmet safe for use.

Tekstvak“Homologation” is the accreditation by an official body, that a specific brand and type of helmet has been produced by a genuine and serious helmet-manufacturer, for a specific use in a specific territory and a specific intended use, and that it has been tested and approved upon a range of pre-defined tests corresponding to established minimum safety standards.

When approved, a helmet receives an official homologation approval mark, that is integrated in or applied to the helmet (mostly sewn onto the chinstrap).

Worldwide a range of homologation standards for motorcycle helmets exist, as many countries have issued different regulations and standards for homologation of motorcycle helmets; this also means that a helmet with a specific homologation is legal to be used only in the territory for which the homologation is valid, often a specific country.

A helmet however can have multiple homologation approvals at the same time, or have an approval of a homologation standard that is recognized by multiple countries, so it can be sold and used legally in these countries and territories.


Regarding the DOT homologation it is important to mention that the DOT compliance label implies that the helmet has been self-certified by the manufacturer or by a third-party tester as meeting the U.S. Department of Transportation Federal Motor Vehicle Safety Standard 218 (DOT FMVSS 218). The standard is enforced by the National Highway Traffic Safety Administration (NHTSA).
However, the simple fact is that a helmet manufacturer may apply the DOT certification label whether the helmet has actually been tested and found to pass all the applicable tests or not. The federal safety standards do not require the manufacturer to provide NHTSA any documentation of test results proving the helmet meets the standards prior to the helmet being labelled that it does meet the standards and being sold to consumers.

As a result of this system, the data shows that currently on any given day, motorcyclists and other helmet purchasers in the U.S. have a greater than 40% chance of purchasing a helmet that does not meet the performance standards they were led to believe it does.

It is common that fake helmets as well as so-called “novelty helmets” have fake homologation marks: For the sake of personal safety, as these “helmets” possibly provide no protection and safety, motorcyclists should only buy helmets of officially known brands and only from accredited and official dealers.


A helmet is only safe if the helmet is free of damage or defects, however minimal they may seem.

For a helmet to be safe for its user, it is important that it has no defects or damage, as it then might not be safe to use anymore.

In case a helmet has been involved a crash, whether damage is visible or not, refrain from re-using the helmet again; any motorcycle helmet is designed for “one-time use only”. This is also the main reason to never buy a second-hand or used helmet with the intention to use it!

For any motorcycle helmet goes that the helmet itself exists of the following 3 layers, from outside to inside: the outer shell, the inner shell and the inner lining.

Regarding defects or damage on a helmet, specifically focus on the following 4 areas of a helmet:

  • The outer shell
    This is the first and hard layer of the helmet, that protects the inner shell as well as the users head for penetrating objects. This outer shell comes in 2 different sorts of material:

    Composite materials (“fibre”), like e.g. carbon or fiberglass, that are often mixed with other materials like Kevlar.
    This composition material is stronger, harder, more rigid and initially longer lasting than its alternative mentioned below. Helmets made with this kind of material are also mostly more expensive than when made with the alternative

    Polycarbonate or materials alike (“plastic”), generally a softer and less rigid material

    As a helmet is an object of use, in time the outer shell might show minor scratches. These however are harmless, as long as these are not the result from a road traffic crash. This also goes – but only to a certain extend – for when a helmet has dropped onto the floor, e.g. from the seat of a motorcycle. As long as this does not happen too often; it does not have negative effects on the helmet, regarding both the outer as well as the inner shell.

    The outer shell absorbs and distributes the first energy of an impact over its surface, and also acts as armour, protecting the softer inner shell and the head of the user against potentially penetrating objects. Any visible damage might indicate that the helmet is not safe to use.

  • The inner shell
    The inner shell is the part of the helmet that protects the users head by distributing and moreover absorbing the energy as a result of an impact

    In most helmets, the inner shell is – still – made of EPS (Expanded Polystyrene, also known as Styrofoam); regarding inner shells in more expensive helmets, based on extensive research by the manufacturers of such helmets, the inner shell is often constructed in several layers, with different densities in material, to achieve maximum energy absorption.

    In line with that, also different materials and alternative inner shell solutions (like e.g. Koroyd), that potentially provide even more safety, are being developed and applied to helmets.

    Any visible damage, like cracks or in form of decay of the material, indicates that the helmet is not safe to use.

  • The chinstrap
    A chinstrap is commonly made of very strong fabric, similar to the material used for safety-belts for cars. It is fixed, mostly riveted, to the outer shell of the helmet. By way of a range of existing fastening-systems, it ensures that a helmet stays in position on the head of the user, during normal use and in case of a crash.

    In case the chinstrap itself is damaged (e.g. it has cuts, it looks ragged), the fastening-system is damaged (e.g. it does not open and / or close effectively anymore) or even defect, or it is or seems not well-attached to the inside of the outer shell anymore, the helmet is not safe to use.

  • The visor (in case the helmet has a visor)
    Like the windscreen of a car, the visor protects the head, face and eyes of a user of a helmet against the elements as well as against potentially penetrating objects, e.g. stones and insects.

    When the visor is (heavily) scratched, it leads to poor visibility for the user during daytime and at night; it is not safe to use the helmet.

    In case the visor is cracked, it might not withstand potentially dangerous objects it gets hit by. In this case, it is not safe to use the helmet.



  1. Regarding (in)visible damage to the helmet, it is important to mention that, in case a user is not sure whether a helmet is still save after e.g. it has dropped, some helmet manufacturers (i.a. SHOEI) offer their users the service to have their helmet checked and tested upon its integrity, hence safety.
  2. Other solutions to check a helmet on (invisible) damage, by e.g. a laser-scan, are being developed and (soon) available.
  3. A helmet is Personal Safety Equipment, to protect and safe the head and the life of its user. Please use and keep it accordingly. For most helmets goes that a visor can be renewed.


From use to maintenance, a helmet must be used properly, as described in the instruction manual.

Carefully read the manual and possible other information that comes with a new helmet, and respect and live-up to its content, regarding “use” as well as “maintenance”.  

Use a helmet in the way it is intended to be used and as is advised by the manufacturer when riding a PTW: So, in case of a (most) modular or so-called flip-up, modular or system helmet, close the front when riding.

Probably most important and most “forgotten” about, as it is a small and seemingly unimportant thing that requires getting used to in doing it and wearing / feeling it, is to always have the chinstrap tightly fastened 
In case the helmet and its user does comply to all of the 5 elements above, but the chinstrap is not fastened at all, or is fairly loose, the helmet might shift into an unwanted position or even be completely removed from the head in case of a crash and therewith is uselesshence unsafe for the user. 


A helmet is permanently exposed to influences that reduce the safety of the helmet: a helmet is in principle “expired” after 7 years from the date of its production, worn or not.

Almost all materials, also the materials of which a helmet is made, are subject to wear and tear.

Factors such as heat, humidity, oxygen, sunlight, vibration, but also sweat, dirt and grease that get into a helmet due to its use, lead to deterioration and degradation of these materials: all these factors have a negative impact on the structural integrity and therewith on the safety provided by a helmet.

As a helmet gets older, it automatically gets weaker, where some parts of the helmet (e.g. the polystyrene inner shell) tend to deteriorate and degrade faster than other parts (e.g. a fiberglass outer shell).

Based on data and information from both the motorcycle industry and the chemical industry, a helmet – any helmet – should be replaced after 7 years, from the date of its production.



Any helmet is subject to the process of ageing and will get weaker over time, whether it is worn frequently, or it is not worn at all.


A helmet should always and everywhere fit tightly around the skull and face. This is extremely important!

In the day-to-day use, “proper fit” of a helmet is probably THE most important element.  

A general rule for a new helmet is that it should fit fairly to very tight and close around the skull and face. 

Helmets, specifically the inner shell of helmets, basically come in 3 different shapes, to correspond with the general shapes of human heads: “round”, “round-oval” and “oval”.  And as a specific brand and / or type of a helmet comes in a specific shape, it is logic that not every helmet will fit on every head, even when it is in the correct size. 

Next to the shape of the inner shell of a helmet, the size of the inside of the helmet is really important: even when the shape is correct, the helmet still can have an improper fit, if it is either too small, hence too tight, or too big and thus too loose around the head. In both situations a specific helmet is unsafe for its user.  

1. Too small 

When a helmet is too small, especially and specifically on and around the skull (measured on a line around the skull, just above the ears), it will lead to irritating and even painful pressure-points, possibly leading to headache, that can and will result in unwanted and dangerous distraction of the PTW rider.  

A helmet that is too small, is unsafe for its user.  

2. Too big 

This means that a helmet has a fairly or very loose fit, also, especially and   specifically, on and around the skull (measured on a line around the skull,   just above the ears), what can lead to the helmet (easily) shifting on the head while riding and manoeuvring a PTW.  

In normal situations this can result in temporarily blinding and distracting   the rider or cause additional and more severe injuries and fractures to e.g. the skull, neck and spine in case of a crash. 

A helmet that is too big, is unsafe for its user.  



  1. By using a helmet, basically any helmet, the inner lining will “sit in” and thus become flatter and thinner, making the helmet bigger on the inside. Based on this fact, it is really important that a new helmet is tight and close-fitting around the entire skull and face. 
  2. It is technically possible to “re-fit” basically any helmet and make it smaller when it is or has become too big. Re-fitting a helmet that is too small is more difficult and not always possible without infringing the structural integrity and thus safety of a helmet. 


A safe helmet is clean and hygienic, on the outside and on the inside of the helmet.

For a helmet to be safe for its user, it should be clean and hygienic, both on the outside and on the inside of the helmet. 

  • Outside – helmet and visor 

Especially In case the outer shell of a helmet features specific safety features, e.g. it is in a fluorescent or light colour and / or it has reflective parts, it makes sense that the helmet from the outside is clean.

More importantly, also In line with article 2. D. in this document, regarding a visor not being defect or damaged, the outside of a visor of a helmet should be clean, to provide optimal visibility for the user of the helmet. 

  • Inside – helmet and visor 

The inside of a helmet, due to wearing it, will get dirty and unhygienic over time: hair, skin cells, grease, as well as a range of germs, bacteria and spores are not uncommon to be found in helmets.   

For this and to keep a helmet safe for its user, it is important to regularly clean and sanitize the inside of a helmet.  

Additionally, the inside of a visor of a helmet should be cleaned regularly, also to avoid it to fog-up quickly and easily. 



When cleaning and sanitizing a helmet, it is very important to only use agents that are suitable for use on the helmet and the visor: it is highly advisable to use special cleaners that do not affect the various materials and thus the safety of the helmet 


No matter the weather conditions, during the day or night, your helmet should always be visible to others.

It is best to choose and wear a helmet with preferably light and noticeable colour(s) and with reflective parts, as it is better seen and visible in the dark. 
In addition, it is always an option and possible to add reflective stickers on the helmet. (This will probably become mandatory with the homologation standard ECE 22-06).


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CASTODIAN Foundation
De Elzen 4
5446 WJ Wanroij
The Netherlands

Tel: +31 612 835 528

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