Not all labs are created equal. Look for ISO/IEC 17025 accreditation, which is the international standard for testing and calibration laboratories. This ensures the lab follows rigorous quality control procedures.

You can usually find the accreditation number on the report. If it's not there, ask the supplier for it. You can often verify the number on the lab's website or through international accreditation bodies. If the lab isn't accredited, the report is worth very little.