How plants are used to make a HEXR helmet

Here at HEXR, we want to revolutionise the helmet industry.

If that seems a bold mission statement, it’s because there is more at stake for us than providing what we believe to be the best helmet on the market. It’s also about radically challenging, and changing, the environmental impact of our industry; protecting the planet as we protect our heads. 

In my past life as a rower for Great Britain, I spent countless hours on the water, surrounded by and immersed in nature. I owe many happy memories to it. Nowadays, as a keen cyclist, I get to experience much the same feeling as I explore beautiful new tracks across the country. With this connection to the natural world, I have felt it is our duty to do what we can to help protect it. At HEXR this has become central to our philosophy.

Expanded Polystrene inside a helmet


Current helmets are made predominantly from expanded polystyrene (EPS), and every year 99% of this material ends up in landfills or in our oceans [1].

The applications for polystyrene are almost always shock absorption, from the packaging that protects our appliances to most types of helmets: motorcycling, alpine, equestrian, and - of course - cycling.

EPS was originally discovered by accident in 1839 by German scientist Eduard Simon, and it contains about 95% air and 5% polystyrene. The exact ratio of air to polystyrene depends on the specific application; some helmets require higher percentages of polystyrene to increase the stiffness and the amount of energy absorption. In any case, the structure of EPS allows it to absorb extremely high amounts of energy for its weight.

But there are serious environmental concerns surrounding both the production and disposal of EPS.

Expanded Polystyrene made from Crude Oil

That production begins with the distillation of crude oil (i.e. a fossil fuel) in an oil refinery. This process separates the heavy crude oil into lighter components such as styrene. Through polymerisation, the styrene molecules join together to form polystyrene. Pentane gas heated to 200 degrees is then used to expand the polystyrene to forty times its size to allow air to enter.

Perhaps more concerning is the lack of effective disposal options for EPS. In 2016 EPS was the most produced plastic in terms of volume [2]. Less than 1% of EPS is recycled because its volume to weight ratio is so high, it is often very expensive, and if the EPS is dirtied or contaminated with other materials it is nearly impossible to recycle [3].

Expanded Polystrene inside a helmet

As a result 80% of EPS ends up in landfills, which contributes to 30% of the global volume of plastics in landfills [4]. Unfortunately landfill isn’t a quick solution as the make-up of EPS means it takes around 500 years to decompose.

The remaining 19% of EPS ends up in our waterways, polluting our oceans and rivers [4]. Since EPS can photodegrade, it breaks down into tiny fragments that are eaten by plankton, fish and sea birds and, as result, enters our food chain.

We live in a period of increased public awareness around the climate emergency, with more pressure on businesses and manufacturers to clean up waste and find greener solutions. This pressure is critical, and it’s time for the next generation of scientists and engineers to take action and innovate.

That’s exactly what we’re doing here at HEXR.

3D printed HEXR helmet

Why we're different:

  • At HEXR we manufacture our helmets from a plant-based material called polyamide-11, made from 100% castor bean oil. This material is sourced sustainably by Arkema and its Pragati initiative, which supports sustainable farming practices, reducing water use, and fair treatment of workers [5].
  • Each helmet is custom produced to fit the individual’s head shape, so we only manufacture helmets when they are asked for. This cuts out the wasted inventory and excess environmental costs of transportation created by mass produced foam helmets.
  • We’ve also designed the helmet with durability in mind. The chin straps, shell, padding and ratchet system are all interchangeable, and if you break or damage the helmet you can simply replace a component, rather than the entire product.
  • Once you’ve finished with your helmet, we’ll arrange for it to be returned to us so that we can recycle it to make new materials for future use.

For all that, there is still a lot more work to be done. We’re on a journey to make a carbon neutral and 100% bio-based helmet, and we hope you’ll join us on the ride.

Cradle to Grave approach at HEXR to commit to a more sustainable future


  1. Lofgren, K. (2015, December). The dangerous truth about styrofoam.
  2. OceanWise Initiative
  3. Recycling Styrofoam. (2014).
  4. Chandra, M. (2016, November). Real Cost of Styrofoam.
  5. Sustainable Castor Initiative (2019).



Email Subscription

Win a Custom Shell

Join our mailing list to be in with a chance of winning a custom painted shell. Winners announced monthly.

You can unsubscribe at any time.

Email Subscription