Sustainability



Make it ISI. Don’t just talk the talk, walk the walk!

In 2018 ISI Soles became the first portuguese outsole producer to get the certification for a integrated management system by the ISO 9001 and ISO 14001.

Make it ISI. Don’t just talk the talk, walk the walk!

In our activity, we take pride in adopting values of sustainable production and eco-efficiency as the benchmark for all operations developed in our factory.

Our environmental concerns begin in the developing stage, where we project the sole’s life cycle and manage to reduce its impact on the environment. In this stage, our designers and technicians define the raw materials, consumption and dimensions of the sole, which later influences the environmental performance in the following stages of production, transportation, consumption and final deposition.



In the production stage, we manage to incorporate 95% of the remaining residues of the sole injection process into our productive cycle. That way, we are able to reduce the production of debris, giving the aforementioned remnants a new (useful) life by blending them with virgin materials. This incorporation of both old and new components is monitored so that there is no decrease of the proprieties of our raw materials.

Using the industrial ecology mindset as the foundation of all our work, we also incorporate the residue of other industries into our own productive process. We reuse cork shavings from the cork stopper industry, along with husk and rubber. Furthermore, we strive to find fresh and new ways to incorporate all sorts of residue in our products, as well as new applications for our own debris.



We are determined to accomplish an increasingly sustainable development in our industry, with focus on reducing our ecological footprint and the environmental impact of both our products and our productive process. We apply several principles of industrial ecology in our everyday work.

We try to predict and avoid pollution in its various ways, promoting recycling habits amongst our collaborators, reusing all kinds of residue, aiming to extend the lifespan of our products as well as using our resources in ever more efficent ways.

We have developed for our customers a line of Vegan soles made from recycled materials.

We have developed for our customers a line of Vegan soles made from recycled materials.

Our collection of Vegan soles has been certified as “Peta – Approved Vegan” by PETA – People for the Ethical Treatment of Animals. This collection does not contain any animal traces and it is conceived in recycled raw materials. We incorporate 95% of the waste resulting from our injection process into our production cycle creating a circular and waste-free economy in which the raw materials are reused permanently.

YES we have outsoles made from worn tennis balls!

300 million tennis balls are manufactured each year. 


At the moment, having no alternative to recycling, the balls end up being sent to landfills where they decompose slowly.

After several laboratory tests, we developed ecological shoe soles out of recycled tennis balls. The incorporation can vary between 10% and 15%. 


This product is certified by the RCS standard.

YES we have outsoles made from worn tennis balls!

Soles made from faulty party balloons

Soles made from faulty party balloons

Every 100 balloons produced is defective. They end up in landfills, where they slowly decompose. 

Aware of this problem we developed a process that allows the manufacture of ecological shoe soles, based on the recycling of faulty balloons. 

A comfortable, durable and environmentally friendly sole. The incorporation can vary between 10% and 15%. 

This product is certified by the RCS standard.