Electrical conductivity or "EC" is a measure of the ?total salts? concentration in the nutrient solution (drip, slab or drain). The higher the ?total salts? concentration in a substrate the higher the EC. An EC will only be registered when inorganic ions are present in solution.

In the context of 2026 aviation, "EC" usually refers to European Commission (EU) Regulations, such as the newly implemented Part-IS (Information Security) and the EU Emissions Trading System (ETS). The EU ETS is a "cap-and-trade" system that effectively puts a price on carbon. Airlines flying within Europe must purchase "allowances" for every tonne of CO2​ they emit. In 2026, the system has reached a critical stage as "free allowances" have been fully phased out, making carbon a direct, high-cost line item on an airline's balance sheet (often €70–€100 per tonne). This "polluter pays" principle forces airlines to invest in more fuel-efficient fleets or Sustainable Aviation Fuel (SAF). For passengers, this often manifests as a "carbon surcharge" or higher base fares on regional European flights, as airlines pass the cost of these mandatory environmental regulations down to the consumer to maintain their thin operating margins.