Aquatic toxicity deals with the effects that substances (synthetic and natural) have on aquatic life when introduced into the environment. Aquatic toxicity is typically communicated as LC50 (lethal concentration to 50% of the affected population) or EC50 (concentration that is expected to have one or more specified effects in 50% of the population) with units of mg/L (milligrams of substance in 1 liter of water).
As with chemical toxicity measurements, higher LC50 and EC50 values indicate a lower toxicity for aquatic organisms. Products that are green certified by ITC labs must have measured or calculated LC50 and EC50 values above certain minimum levels making them less likely to cause harm to aquatic organisms if introduced into the environment.