The fight to prevent the importation of products made with forced labor is proceeding on two fronts: science and law.

On one hand, regulators are turning to advanced methods for detecting the origin and content of goods entering the U.S., especially through DNA and chemical analysis of commodities such as cotton.

And on the legal front, laws such as the Uyghur Forced Labor Prevention Act (UFLPA) are aimed at stopping the importation of materials and finished products manufactured with forced and child labor in the Xinjiang Uyghur Autonomous Region (XUAR) of China.

Both efforts have yielded some results. Chemical analysis of materials at the molecular level can reportedly pinpoint the origin of agricultural materials down to the specific farm. And, under the authority of UFLPA, U.S. Customs and Border Protection has detained an estimated $1.7 billion of shipments, and denied entry to about a fifth of those, since the law was enacted in 2022.

But that success rate is complicated by the expansion of CBP’s UFLPA Entity List to include additional countries, among them Malaysia, Vietnam and Thailand, reflecting the circuitous routing of goods manufactured in Asia, and the difficulty of determining the actual origin of specific commodities and products.

For its part, China is seeking additional ways to get around UFLPA, including by shifting ethnic Uyghurs under conditions of forced labor from the western region of Xinjiang to factories in other parts of the country – making regional determinations irrelevant.

The newest wrinkle in this tortured tale emerged in a recent article by freelance writer Daniel Murphy for the nonprofit Bureau of Investigative Journalism. It revealed that China is converting detoxified cottonseed from Xinjiang Province into animal feed, which is sold to farmers across China. Murphy’s article raises the possibility that the chickens and other animals ingesting the feed are ending up in products sold in the United Kingdom and possibly Iceland. (The U.K. is under pressure to pass a ban similar to that of UFLPA on products made with forced labor in Xinjiang Province.)

Murphy spent years investigating forced-labor practices in the Thai and Chinese fishing fleets. “This is a supply chain that has six to seven tiers of risk upstream,” he says. “It’s right at the root of these food supply chains.”

The practice of converting cottonseed to feedstock greatly complicates efforts to trace food products back to their source, for purposes of ensuring ethical labor practices in Asia and elsewhere. Murphy wonders the extent to which food companies themselves are aware of the origin of their end products. “We didn’t receive clear responses,” he says. “It remains a question that the food sector needs to grapple with.”

So far, Murphy’s story hasn’t gained much traction in the major media, but it has triggered concern among some companies that source product in China. “This was pretty shocking,” says Alex Bowles, director of global client services with Transparency-One, creator of a platform and partner network for tracing products across global supply chains. Its customers in apparel and retail are “very invested in compliance on this topic,” he says, with cotton being a key ingredient in their products. “What we weren’t expecting to see is that same cotton making its way into supply chains for some of the largest food retail brands in the world.”

Surveys show that, on average, fewer than 35% of brands have visibility beyond their direct Tier-1 suppliers, Bowles says. “That tells us, first and foremost, that a lot of these global brands are pretty siloed in how they are tracing and identifying their subtier supply chains.”

Sanctioned cotton showing up in protein supply chains adds another level of difficulty in determining the origin and makeup of food products. But the tools for making such determinations are there, Bowles insists. It starts with understanding every level of a multi-tier supply chain — clearly a growing challenge for food producers, given this latest revelation — then reviewing all existing certifications and documentation indicating a producer’s or country’s inclusion on sanction lists.

That effort needs to be combined with diligent product testing and “boots on the ground auditing,” Bowles says. Scientific methods such as DNA, isotopic and chemical “fingerprinting” analysis can help, although whether they’re of value in the case of Chinese feedstocks remains an open question.

“I made an effort to talk to experts in that field,” says Murphy. “I found that particular technology is likely to be of limited use in this specific context. The process of taking fermented cotton byproducts transformed by technology, and putting that into animal feed, essentially wipes out the fingerprint.”

What’s certain is that companies at every stage of the global supply chain need to up their efforts to identify the origin of products and the labor that went into making them. This latest in a long series of revelations about China’s labor practices “reflects a significant challenge that needs to be met,” Murphy says.