Codex, Substantial Equivalence and WTO Threats to National GMO Labeling Schemes

This policy brief by the Center for International Environmental Law argues against the adoption of the "substantial equivalence" test as an international standard for GMO labeling by the Codex Committee on Food Labeling. The authors contend that this approach is scientifically inadequate and that its adoption would allow the World Trade Organization (WTO) to challenge and potentially strike down more stringent national labeling laws, particularly those based on consumer right-to-know or ethical and religious concerns.

• The "substantial equivalence" approach, which treats a GMO food product as safe if it sufficiently resembles a traditional product, is criticized by the international scientific community as an inadequate safety test. Specific criticisms include that it allows for rapid commercialization without testing for unintended side effects (such as post-release gene transfers), ignores the inherent risks of recombinant DNA techniques, and overlooks evidence regarding the horizontal transfer of antibiotic-resistance marker genes.
• Standards adopted by Codex are likely to be recognized as "international standards" by the WTO under the Agreement on Sanitary and Phytosanitary Measures (SPS Agreement) and potentially the Agreement on Technical Barriers on Trade (TBT Agreement). Because the WTO prefers domestic laws based on international standards to reduce trade barriers, a Codex endorsement of substantial equivalence would create a benchmark used to test the consistency of national GMO labeling laws.
• National laws that are more stringent than the substantial equivalence standard—such as those requiring the labeling of all GMO products—would lose the presumption of WTO consistency. Under the SPS Agreement, exceeding international standards requires scientific justification, which may fail to account for non-safety factors like ethical, religious, or dietary concerns. Under the TBT Agreement, exceeding standards is only permitted if the international standard is inappropriate for a "legitimate objective."

APA

Stilwell, M., & Van Dyke, B. (n.d.). Codex, Substantial Equivalence and WTO Threats to National GMO Labeling Schemes. Center for International Environmental Law. https://www.ciel.org/wp-content/uploads/2015/03/CODEXSubstantialEquivalenceandWTO.pdf

Chicago

Stilwell, Matthew, and Brennan Van Dyke. Codex, Substantial Equivalence and WTO Threats to National GMO Labeling Schemes. Center for International Environmental Law, n.d. https://www.ciel.org/wp-content/uploads/2015/03/CODEXSubstantialEquivalenceandWTO.pdf.

Wikipedia

{{cite report |last1=Stilwell |first1=Matthew |last2=Van Dyke |first2=Brennan |title=Codex, Substantial Equivalence and WTO Threats to National GMO Labeling Schemes |publisher=Center for International Environmental Law |url=https://www.ciel.org/wp-content/uploads/2015/03/CODEXSubstantialEquivalenceandWTO.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{stilwellndcodex, author = {Stilwell, Matthew and Van Dyke, Brennan}, title = {{Codex, Substantial Equivalence and WTO Threats to National GMO Labeling Schemes}}, institution = {Center for International Environmental Law}, url = {https://www.ciel.org/wp-content/uploads/2015/03/CODEXSubstantialEquivalenceandWTO.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }