Used as a reference standard in environmental testing laboratories to calibrate instruments and validate analytical methods for detecting bismuth in water samples. Ensures accuracy and reliability in monitoring bismuth levels, especially in regulatory compliance, pollution studies, and drinking water safety assessments. Commonly employed in atomic absorption spectroscopy, inductively coupled plasma mass spectrometry (ICP-MS), and other trace metal analysis techniques. Helps maintain consistency across measurements and supports quality control in large-scale water quality programs.