ISO 5354: Navigating the new requirements for cotton DNA testing
In the 2010s, the organic cotton industry was facing a growing threat. With many brands looking to make sustainability claims in the age of the more eco-conscious consumer, the sector witnessed increased scrutiny around the presence of genetically modified (GM) cotton in its supply chains.
A number of factors came into play here, including cotton processing degrading or even destroying available DNA, making reliable testing more difficult. Therefore, a different approach to GMO testing was essential to overcome this.
In response, IWA 32:2019 was introduced as an interim measure, providing requirements and recommendations for laboratories conducting GMO analysis in cotton and textiles. However, this International Workshop Agreement was designed to provide a rapid response to an emerging market need rather than serve as a permanent International Standard, ultimately setting the stage for the ISO 5354 series.
In this insight, we will discuss how cotton DNA testing must now conform to ISO 5354-1:2025 and ISO/TS 5354-2:2024 and how certified organizations can prepare for their implementation under GOTS.
Shifting from IWA 32:2019 to ISO 5354
The International Workshop Agreement (IWA) 32:2019 provided a necessary stopgap for the organic cotton industry. It established requirements and recommendations for laboratories carrying out GMO analysis.
However, the IWA was never intended to be a permanent solution and ISO 5354-1:2025 and ISO/TS 5354-2:2024 have since been introduced to deliver a more comprehensive and harmonized approach. Together, these two documents provide textile testing facilities with standardized DNA extraction methods alongside guidance on target sequences for identifying GMO signatures.
As a result, it is hoped that the ISO 5354 series will bring increased reliability and accuracy to organic cotton verification.
What exactly is changing?
Due to the urgent nature of introducing IWA 32:2019, recommended DNA extraction methods and genetic screening protocols were initially included in one brief document. Though this certainly helped to implement the temporary agreement efficiently, without clear and harmonized test methods, differences in lab interpretation could still impact the results.
To address this, ISO 5354 separates DNA extraction methods and genetic screening protocols into ISO 5354-1:2025 and ISO/TS 5354-2:2024, respectively, with the two documents offering far more detail, including workflows, benchmarks and standardised methodologies.
In addition, ISO/TS 5354-2:2024 provides a list of target sequences that can be used to screen for GM material and guidance for screening currently established GM cotton events (International Organization for Standardization, 2024).
The new approach also emphasizes an important limitation of GMO testing. The further cotton moves through processing, the more difficult reliable DNA analysis can become. ISO 5354-1 makes clear that GMO admixtures cannot be reliably detected in cotton fiber and cotton fiber-derived materials, highlighting the importance of testing earlier in the supply chain (International Organization for Standardization, 2025). Ginners and raw cotton suppliers are now the critical point of testing, since only raw/greige cotton and cottonseed testing is accepted as valid verification. Therefore, testing further down the chain (e.g., yarn, fabric, processed products) cannot substitute for it.
How to prepare for ISO 5354 standardization
With the ISO 5354 requirements incorporated into GOTS Version 8.1 (Global Standards gemeinnützige GmbH, 2026), certification holders have until 1 March 2027 to prepare for their full implementation.
As the deadline approaches, organizations are being encouraged to take practical steps to avoid wasted time, money and effort down the line.
Check your GOTS criteria
The Global Organic Textile Standard (GOTS) is the world’s leading standard for organic textiles and its Version 8.1 framework (Global Standards gemeinnützige GmbH, 2026) incorporates the ISO 5354 requirements into its approach to GMO testing. Therefore, if you want to continue to be GOTS-certified, you will need to follow the new methodologies and rules around testing.
Certificate holders should begin requesting ISO 5354-compliant test reports well ahead of the 1 March 2027 deadline as testing conducted later under the old IWA 32:2019 method will not carry forward once the standard changes.
Don’t wait for the finished product
Under the latest GOTS framework, GMO screening should be conducted on unprocessed (raw/greige) cotton, with testing of chemically processed cotton not accepted as valid verification. Rather than waiting until the final product is ready for testing, you should factor GMO verification into your processes much earlier to avoid unwanted delays and costs.
Review your existing procedures and processes
The separation of DNA extraction methods and target sequences is a essential part of the move from IWA 32:2019 to ISO 5354. Therefore, you should check that your existing processes accommodate this change and that your procedures meet the requirements and guidance set out in ISO 5354.
For example, for operators sourcing from multiple ginners or working with blended-origin cotton, transaction certificates and scope certificates should reference the test method used and confirm it was applied to the raw/greige material at the point of origin.
ISO 5354 signifies a major shift in GMO testing for organizations working across the organic cotton supply chain. The brands that will benefit most are those who consider GMO testing from the very start of the process rather than as an afterthought when the finished product is ready to push to the market.
By preparing well in advance, you can avoid delays in certification or re-certification, additional and costly testing time, and sourcing disruptions. Speak to one of our textile testing specialists to stay ahead of the curve and maintain consumer trust as we enter this new age of cotton DNA testing.