3 Key Insights from CBP’s New Isotopic Testing Guidance for UFLPA Compliance

On November 12, 2024, U.S. Customs and Border Protection (CBP) released its first detailed guidance on isotopic testing, outlining a science-based approach to verifying the geographic origin of materials under the Uyghur Forced Labor Prevention Act (UFLPA). CBP shared recommendations for choosing reliable testing providers and encourages importers to test early as part of their due diligence program.

Here are three key insights from the guide that every importer and retailer should know.

1. Isotopic testing is key to verifying material origins

With the UFLPA in effect since June 2022, supply chain traceability has been a critical element of importers’ due diligence efforts. The Act allows CBP to detain goods presumed to be made with forced labor from entering the United States. The new CBP guidance highlights isotopic testing as a critical tool for determining the geographic origin of materials, particularly high-risk commodities like cotton.

“Isotopic testing is a scientific method that identifies the atomic structure of naturally occurring materials, or a “fingerprint” of the material, affected by local environmental conditions. For example, in the case of cotton, it is the environmental conditions experienced by the plant during growth, not the seed’s origin, that will determine the isotopic fingerprint of the cotton fiber. When that fingerprint is compared to a library of like materials from various geographic areas, the test can determine that the raw material is consistent with the claimed geographic origin.”

- CBP Guidance Document

2. CBP encourages private sector testing

CBP has tripled its isotopic testing capabilities in recent years, but their testing is more focused on identifying risks, which means importers are still responsible for conducting due diligence to monitor their supply chains. CBP encourages importers to take a proactive role by engaging private sector testing providers.

“Even with these additional investments, CBP will have limited testing resources and does not have the capacity to test all U.S. imports. This is why CBP continues to encourage the inclusion of private sector testing in importer due diligence programs to help identify and manage risk.”

- CBP Guidance Document

3. Choosing a provider that meets CBP standards matters

According to CBP, importers should look for providers with scientific expertise, advanced equipment, and trained experts required for isotopic testing and interpretation. Some of the key standards include:

• Chain of custody: Isotopic testing providers must document the handling of samples, from receipt of the sample through disposition.
• Reference library: Providers should have access to a statistically robust library with known-provenance samples from all commercially relevant growing regions.
• Statistical modeling: Providers must use advanced models to interpret isotopic data and determine geographic origins.
• Accreditation: Laboratories should meet ISO/IEC 17025 standards and participate in proficiency testing.

“The test provider should have a statistically significant number of materials in its in-house reference library in order to confidently verify origin. Materials in the reference library should have known provenance and should represent all commercially relevant growing regions being tested.”

- CBP Guidance Document