NOEC definition

NOEC means no observed effect concentration. The NOEC is the highest concentration of toxicant (e.g., effluent) to which organisms are exposed in a chronic toxicity test [full life-cycle or partial life-cycle (short term) test], that causes no observable adverse effects on the test organisms (i.e., the highest concentration of effluent in which the values for the observed responses are not statistically significantly different from the controls).

NOEC means No Observed Effect Concentration.

NOEC means the highest tested concentration of a toxic substance, wastewater effluent or other aqueous mixture at which no adverse effects are observed on the aquatic test organ- isms at a specific time of observation. The NOEC is determined using hypothesis testing.

Examples of NOEC in a sentence

• Express the test NOEC as TUc (Chronic Toxic Units), by dividing 100/NOEC for DMR reporting.

• Results which cannot be quantified (i.e., a “less than” NOEC value) are not acceptable, and a retest will have to be performed.

• The chronic tests to use are: Chronic 3-Brood Survival and Reproduction Static Renewal Test with Ceriodaphnia dubia (EPA Method 1002) Chronic 7-Day Survival and Growth Static Renewal Test with Pimephales promelas(EPA Method 1000)These chronic tests shall be conducted in such a manner and at sufficient dilutions (minimum of five dilutions, derived geometrically) to determine the "No Observed Effect Concentration" (NOEC) for survival and reproduction or growth.

• In order to determine which treatment(s) are statistically significant and which are not, for the purpose of reporting a NOEC, the relative percent difference (RPD) between the control and each treatment must be calculated and compared to the lower PMSD boundary.

• The NOEC (No Observed Effect Concentration) is herein defined as the greatest effluent dilution at and below which toxicity (lethal or sub-lethal) that is statistically different from the control (0% effluent) at the 95% confidence level does not occur.

More Definitions of NOEC

NOEC means no observed effect concentration. The NOEC is the highest concentration of toxicant (e.g., effluent) to which organisms are exposed in a

NOEC means the highest tested concentration of a toxic substance, wastewater effluent or other aqueous mixture at

NOEC. ’ means no observable

NOEC means no observed effect concentration. The NOEC is the highest concentration of toxicant (e.g., effluent) to which organisms are exposed in a chronic toxicity test [full life-cycle or partial life-cycle (short term) test], that causes no observable adverse effects on the test organisms (i.e., the highest

NOEC means the “no observed effect concentration”.

NOEC means the "no observed effect concentration" which is the highest concentration of effluent in a toxicity test shown to have no statistically significant adverse effects when compared to an appro- priate control.

NOEC means ‘ no observed effect concentration’. It is the highest concentration at which no effect on test organisms is observed over a relatively long period in a chronic aquatic toxicity test.