Safety is the highest priority for children's apparel. You must ensure products comply with CPSIA (Consumer Product Safety Improvement Act) for the U.S. market, which regulates lead content and phthalates, or the EN 14682 standard for the EU, which focuses on the safety of cords and drawstrings to prevent strangulation. Additionally, look for OEKO-TEX® Standard 100 certification to guarantee the fabric is free from harmful substances, and GOTS (Global Organic Textile Standard) if you are sourcing organic cotton sets.