Written by the Fiveable Content Team • Last updated September 2025
Verified for the 2026 exam
Verified for the 2026 exam•Written by the Fiveable Content Team • Last updated September 2025
Definition
The EC50, or Effective Concentration 50, is the concentration of a substance at which 50% of a specific biological response or effect is achieved. It helps determine the potency of a substance.
Related terms
IC50 (Inhibitory Concentration): The IC50 represents the concentration of a substance required to inhibit a specific biological function by 50%. It is commonly used in pharmacology and biochemistry.
MIC (Minimum Inhibitory Concentration): MIC refers to the lowest concentration of an antimicrobial agent that inhibits visible growth of microorganisms.
Threshold Limit Value (TLV): TLV is the airborne concentration level below which it is believed that nearly all workers may be repeatedly exposed without adverse effects.