A product’s Life Cycle Assessment (LCA) is an analysis of the environmental impact of a product during its entire lifecycle. This is split into five sections: global warming, eutrophication, water scarcity, resource depletion/fossil fuels and chemistry.  We use standardised tools provided by the Higg Index to gain an objective score alongside each category that can not only help us benchmark our progress but also help you compare our products and others. 

If you’ve ever looked at our product page you have probably come across our carbon number. 

Our numbers differ from product to product but consistently outperform the average running shoe. This number represents the global warming impact: the amount of emissions that are released into the atmosphere during the life cycle of said product, expressed in kg CO2 equivalent (kg/co2e). 

We calculate and publish our carbon number in an effort to be transparent about the environmental impact of our products.

What is an LCA?

When calculating the LCA of a product, all processes and inputs needed to produce that particular product are considered. This includes processes all the way down the supply chain including raw material extraction, as well as dye or post production printing methods used. A cradle to grave approach was taken, meaning that the LCA we conduct includes all stages from the beginning to the end of life of our products. These stages can be broken down into:

Raw materials The impact associated with the cultivation, extraction and production of raw materials.

Finished Goods Manufacturing  
The impacts of the different manufacturing processes involved in making and assembling products.

The materials that make up our packaging.

This includes inbound transportation of the final product from the factory to our warehouses and outbound transportation from the warehouse to our customers or retailers.

This section considers energy used at the distribution centre as well as any retail partners.

Product Care
This looks at customer care and the impact of processes such as washing, drying and number of wears. 

End of Use / Duration of Service
These final two steps take into account any repair, rewear or recycle schemes as well as material properties alongside any relevant material claims made. 
The scenario we use assumes that the majority of our products end up in landfill. We chose this path for now until we have more accurate data on the paths our products take as well as the uptake of our recycling programme.
The weights of the items for footwear are based on a UK9 and for apparel on a men's medium.

The Life Cycle Assessment we conduct looks at five impact categories. For the carbon number we focused on the Global Warming Potential (GWP) which is expressed in CO2 equivalent.

We will be expanding and reporting on the other four impact categories in the future.


As part of the Sustainable Apparel Coalition (SAC) we make use of the Higg Index and its tools. The Higg Index is a suite of tools for the standardised measurement of value chain sustainability. Developed collaboratively over the last decade by a coalition of brands, retailers, manufacturers, and other footwear, apparel and textile industry stakeholders through the SAC.

This platform gives us access to standardised life cycle assessment (LCA) data. The Higg tools and databases are built in accordance with the Ecoinvent data quality guidelines, ISO 140404 /14044 and the PEF Guide. We can further customise the materials and production processes to better reflect our products.

This means that the data we use is an indication of our environmental impact and is not 100% representative of the impact of our products. Whilst we do our best to obtain as much information as possible and have made good progress, we currently do not have all the primary data for all of our materials and all the processes involved in the making of hylo products.


We will continue to publish a carbon number for every product we bring to market.