Can one activewear product be certified by GRS and OEKO-TEX® (and GOTS if applicable)?

Yes. One garment can carry multiple certifications (e.g., GRS + OEKO-TEX®) as long as the materials, processing, and traceability meet each standard's requirements. GRS focuses on recycled content + chain of custody + environmental/social criteria, while OEKO-TEX® focuses on product safety (harmful substances). GOTS mainly applies to organic natural fibers (like organic cotton) with strict processing rules.