The Composting Council Research & Education Foundation invested in an important report that continues its commitment to research and education of compost users and producers. A detailed research paper was produced featuring the current literature on soluble salts in compost and soils.
You can learn more about what electrical conductivity means for compost, like how a higher E/C may not mean a danger to plants. Compost E/C is a complex issue that the University of Wisconsin explains more here.