Organic cotton – here‘s what you need to know about testing

As the fashion industry continues its shift towards a more sustainable footing, organic cotton is becoming an increasingly popular fibre choice.

Organic cotton refers to cotton that is grown from non-GMO seeds without the use of toxic and persistent pesticides and fertilisers. It uses natural farming practices that support healthy soil, increase biodiversity, and reduce the fibre’s water footprint. As such, it has many advantages over conventional cotton. It is healthier for the land, the farmers, and their communities. It promotes food security, provides higher financial returns for farmers, and empowers women, who currently make up around 10% of organic farmers worldwide.

Conversely, with its heavy use of chemicals, water and energy-intensive production, and attendant social impacts, conventional cotton is difficult to fit within any picture of a sustainable fashion industry.

However, for a garment to be sold as organic, it must be organic. As most brands and retailers buy finished garments rather than fibre or fabric, they must rely on organic certifications such as the Global Organic Textile Standard (GOTS) or the Organic Content Standard (OCS). OCS allows label claims of ‘made with X% organically grown cotton’ while to carry the GOTS ‘organic’ label garments must contain at least 95% certified organic fibres. Garments with a minimum of 70% certified organic fibres can carry the label ‘made with organic’.

GOTS is the most recognised standard, and the most stringent. Neither GOTS nor OCS cover organic fibre production, which is governed by national organic standards. Both require complete chain of custody certification, while GOTS includes environmental and social requirements for fibre processing. Its aim is to define ‘worldwide recognised requirements that ensure the organic status of textiles’ and it covers the processing, manufacturing, packaging, labelling, trading, and distribution of all textiles made from at least 70% certified organic fibres. Chemical use throughout the manufacturing process is strictly regulated and all processors and manufacturers must comply with the ILO’s (International Labour Organisation) minimum standards. Compliance is checked through on-site audits and residue testing.

Because there are so many possible risks for contamination throughout the manufacturing process, every company and individual in the chain of custody must be certified by a GOTS certification body.

Testing by a laboratory is an important aspect of certification, but it is not the be-all and end-all. Organic standards define a process for producing organic textiles. Lab testing controls the efficiency of that process and determines whether the product conforms to the limit values of the standard. However, it is advisable for all brands and retailers to carry out testing on both raw materials and finished garment to confirm the integrity of the certification process and the absence of GMOs and banned chemicals.

It is not uncommon for organic cotton garments to fail these tests. If this happens, they cannot legally be marketed as organic. It is a more widespread problem than many realise, and retailers have been known to withdraw their organic ranges because they are unable to guarantee that organic really means organic. But why does this happen and what should the industry do about it?

Worldwide, non-organic cotton predominates. In some major cotton producing countries, up to 95% of cotton is genetically modified and the use of toxic and synthetic chemicals is widespread. This makes accidental contamination a very real issue. In many cases, access to non-GMO seeds is limited, and contamination can occur at any point, from farm equipment or during transport, to storage and ginning. In the same way, pesticide drift from neighbouring non-organic farms can contaminate fields sown with organic cotton.

There are other issues. With demand outstripping supply and organic cotton traditionally commanding higher prices, there can be an incentive to substitute non-organic for organic fibres or mix the two together. Since the difference is not visible, testing is the only way to know whether such substitution has taken place. Verifying the organic status of garments also protects brands from potential reputation damage when making the organic claim in their marketing campaigns.

In 2019, the ISO/IWA 32:2019 “Screening of genetically modified organisms (GMOs) in cotton and textiles” has been developed as a widely accepted testing method for GMO detection in cottonseed, leaf, cotton fibre and cotton fibre-derived materials.

Our network of labs can test all the chemical parameters of GOTS as well as GMOs according to ISO/IWA 32:2019, which was developed by GOTS, the Organic Cotton Accelerator (OCA) and Textile Exchange to create a standard among laboratories worldwide on GM cotton screening along the organic cotton value chain. For better clarity on laboratories’ competency, the organisations have set up the proficiency test initiative on the ISO/IWA 32:2019 standard, and Eurofins is one of the fourteen laboratories worldwide passing the proficiency.

In addition, our chemical testing service covers around 200 pesticides and 250 toxic substances used in processing, and we report back on parts per million/billion. If a client does not want to test for the full list, we can make a recommendation on which tests to carry out.

The GMO analysis is performed in two steps. First, the DNA is extracted from the sample material and then tested for the presence of genetically modified sequences. In parallel, the presence of cotton DNA is verified to allow a correct interpretation of the GMO results. As DNA can be degraded and destroyed during the manufacturing process, it is important to verify that cotton DNA is still detectable.

Learn more about our Organic Cotton Identification Services.

The fact that it is common for garments to fail these tests underscores the need for verification, and the importance of robust processes throughout the supply chain. What it doesn’t mean is that the fashion industry should turn its back on organic cotton. Organic farming is as much a process as an end product, and one that is infinitely kinder to people and planet. Instead, companies must acknowledge the issues and decide on their goals. Not every company is at the same place in their sustainability journey, which is why there are different levels of certification. Companies that cannot yet meet the eco and social criteria of GOTS can use the Organic Content Standard.

Improving traceability and trust in the supply chain, not just for organic cotton, is vital if the fashion industry is to move to a more sustainable footing. Transparency protects brands, it protects consumers and, ultimately, the farmers. But, like so many things, real progress will take collective effort to identify barriers and work on long-term solutions.

*Textile Exchange Organic Cotton Market Report 2019