For B2B buyers, especially those targeting the US and EU markets, compliance with REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) and RoHS (Restriction of Hazardous Substances) is critical to ensure the stones are free from harmful levels of lead and cadmium. If the stones are intended for children's products, they must meet CPSIA (Consumer Product Safety Improvement Act) standards. Always request third-party lab test reports (e.g., SGS or Intertek) from the supplier.