Acute to Chronic Ratio definition

Acute to Chronic Ratio or "ACR" means the ratio of acute toxicity expressed as an LC50 for a
Acute to Chronic Ratio or "ACR" means the ratio of acute toxicity expressed as an LC50 for a specific toxicant or an effluent to the chronic value for the same toxicant or effluent.
Acute to Chronic Ratio means LC50/NOEC. The NOEC is the highest concentration at which no effect on test organisms is observed over a relatively long period. Quarterly biomonitoring over the life of the permit is sufficient to determine the ACR if the NOEC and LC50 may be determined. If the ACR is unknown, a default value of 10 may be used for implementation purposes.

Examples of Acute to Chronic Ratio in a sentence

  • Much of the discussion with the CNMC and stakeholders also addressed approaching inter-sectoral coordination in a complex, dynamic institutional set-up, under the umbrella of IWRM.

  • Acute to Chronic Ratio (ACR) 10.EPA believes that monitoring results below these benchmarks indicate that a generally effective SWPPP is beingimplemented at a facility, and that further monitoring should not berequired.

  • The predictions are sufficiently robust and are appropriate for the purposes of chemical safety assessment.Acute to Chronic ratiosIt is generally assumed that for MoA 1 substances the Acute to Chronic Ratio (ACR) is below 100 and ranges from 1 to 10.

  • In using an Acute to Chronic Ratio, it is assumed that the increased sensitivity the stonefly exhibited on an acute basis, will be exhibited on a chronic basis and may result in an overestimation of toxicity to the organism, thus there is some uncertainty surrounding the use of ACR risk estimation of the stonefly and Salt Marsh Water Mosquito.

  • As stated in the 1985 guidelines, “the Final Acute-Chronic Ratio should be calculated as the geometric mean of the acute-chronic ratios for species whose SMAVs are close to the Final Acute Value.” The guidance does not quantify “close”, but it also does not specify that the Acute to Chronic Ratio (ACR) should only be derived from a single ACR from the study with the acute value that is closest to the Final Acute Value (FAV).

  • The selection and the Acute to Chronic Ratio (ACR) to serve as the Final Acute to Chronic Ratio (FACR) and its application to derive the Final Chronic Value (FCV) for PFOA is acceptable.


More Definitions of Acute to Chronic Ratio

Acute to Chronic Ratio means the ratio of the acute toxicity, expressed as an LC50, of an effluent or a toxic substance, to its chronic toxicity. It is used as a factor to estimate chronic toxicity from acute toxicity data.

Related to Acute to Chronic Ratio

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