Understanding material specifications

What lies behind the information on our eyewear?

Our Eschenbach eyewear uses acetate sheets supplied as Eastman Acetate Renew. The eyewear frames, excluding lenses and metal components, are linked to 27% ISCC-certified recycled material through the ISCC PLUS mass balance approach.

Two different processes make this measurable and traceable, both are explained below.

PROCESS 1

ISCC PLUS Mass Balance: certified quantity allocation

In the production of acetate, certified raw materials, such as bio-based or recycled materials, are processed together with conventional materials. They can no longer be physically separated in the finished product.

The mass balance approach ensures that it is precisely documented how much certified material has been used in production. The amount linked to the product corresponds exactly to the amount procured for the manufacturing process.

A familiar example:

Those who purchase green electricity do not receive their wind or solar power directly through their household socket, as the electricity in the grid is mixed. Nevertheless, it is certified that a corresponding amount of renewable energy has been fed into the grid. The mass balance principle follows the same approach.

1  An equivalent amount of certified raw material is procured for the manufacturing process

2  The quantity is precisely documented and verified by ISCC PLUS

3  The corresponding quantity is attributed to the finished product

ISCC PLUS (International Sustainability and Carbon Certification) is part of a globally recognised certification system for sustainable and transparent supply chains.

PROCESS 2

ASTM D6866: scientific measurement of bio-based content

The bio-based content of our acetate is measured using a recognised laboratory method, the ASTM D6866 standard. It uses radiocarbon analysis (also known as the C14 method) to determine how much of the material actually originates from renewable resources.

How does it work? Living plants absorb CO2 from the air during their growth, which contains a measurable proportion of C14 carbon. Fossil raw materials such as crude oil no longer contain this proportion, as it has decayed over millions of years. In the laboratory, it can be precisely measured whether and to what extent a material is of biological origin.

The result is a specific percentage value* – independently measured, not self-declared. The method is internationally standardised and recognised by certification bodies worldwide.

Both processes ensure transparency:

The information relating to our models using Acetate Renew is based on traceable, verified and certified processes.

*The percentage values refer to the composition of Eastman Acetate Renew. The ISCC PLUS percentage value refers to the certified component: eyewear frames, excluding lenses and metal components. The frames are linked to 27% ISCC-certified recycled material through the ISCC PLUS mass balance approach. The bio-based content is measured according to ASTM D6866-22 Method B.