Used primarily as a reference standard in environmental and industrial testing to calibrate analytical instruments such as gas chromatographs. It helps in the accurate detection and quantification of 1,1-dichloroethylene in air, water, and soil samples, especially in monitoring industrial emissions and contaminated sites. Commonly employed in laboratories complying with EPA methods for volatile organic compound (VOC) analysis. Also used in research settings to study degradation pathways and exposure levels in occupational health studies.