Fish LC50 Calculator

Observed fish exposure-matched lethal concentration 50 percent endpoint across independently qualified assay records, not generic mammalian LD50 or cross-species equivalence. Piecewise-linear response versus log exposure, no extrapolation, no fabricated fitted model. Assay protocol, background correction, replicate uncertainty and biological interpretation independent; no test procedures or handling safety advice.

Description

A fish LC50 concerns a lethal-concentration endpoint in a specified aquatic assay.

A fish LC50 concerns a lethal-concentration endpoint in a specified aquatic assay.^[1]

Species, exposure conditions and duration must remain attached to the tested response record.

When to use Fish LC50 Calculator

Use this tool to interpolate the bracketed assay endpoint under the declared response convention. Establish the chemical, exposure route, endpoint, measurement basis and independently applicable assay or assessment reference.

How to use Fish LC50 Calculator and understand its results

Establish the chemical, exposure route, endpoint, measurement basis and independently applicable assay or assessment reference.
Enter actualTestedExposureCoordinates, actualIndependentlyQualifiedEndpointFractions, callerVerifiedAssayIdentityAndDuration, using the field meanings and rules below, then run the tool.
Read observedLogInterpolatedAssayEndpoint in the tested exposure-coordinate units. Review the assay context and uncertainty separately.
Correct any reported input issue and run again. Before using a successful result, check the stated units, signs, reference scope and observation coverage.

Input field	Meaning	Value type	Requirement
actualTestedExposureCoordinates	Actual tested exposure coordinates	list of number	Required
actualIndependentlyQualifiedEndpointFractions	Actual independently qualified endpoint fractions	list of number	Required
callerVerifiedAssayIdentityAndDuration	Caller verified assay identity and duration	string	Required

Require at least two aligned observations: exposure coordinates must be strictly increasing and positive, and response fractions must lie in [0,1] and be nondecreasing. The fixed target 0.5 must fall within the observed response range. A unique exact target hit returns its exposure; repeated exact target hits fail as an ambiguous plateau. Otherwise interpolate response linearly against natural-log exposure and exponentiate. No extrapolation, regression, confidence interval or automatic background correction is performed. Enter a nonblank qualified assay context, which is retained with the result.

endpoint=exp(ln(d_i)+(ln(d_(i+1))−ln(d_i))×(0.5−p_i)/(p_(i+1)−p_i))

Use the matching field units and the exact boundary, ordering and reference rules above.

Output field	Meaning	Value type
result	Qualified observed calculation or explicit reference	object
result.observedLogInterpolatedAssayEndpoint	Assay exposure coordinate at the target response under log-exposure interpolation.	number
result.assayContext	Caller-supplied qualified assay identity and duration, returned unchanged.	string

json

{
  "input": {
    "actualTestedExposureCoordinates": [
      1,
      10,
      100
    ],
    "actualIndependentlyQualifiedEndpointFractions": [
      0.25,
      0.5,
      0.75
    ],
    "callerVerifiedAssayIdentityAndDuration": "fish exposure-matched lethal concentration; actual independently verified source/edition and units"
  },
  "output": {
    "result": {
      "observedLogInterpolatedAssayEndpoint": 10,
      "assayContext": "fish exposure-matched lethal concentration; actual independently verified source/edition and units"
    }
  }
}

Limitations and assumptions

Chemical identity, route, assay, exposure basis and reference applicability are caller-established. The output supplies no causal conclusion, universal toxicity threshold or authoritative regulatory determination. Endpoint interpolation summarizes the supplied qualified assay observations; it does not supply a fitted toxicological model or an uncertainty estimate.

Missing required fields, unknown fields, wrong types and violated rules return input issues. Numeric values and outputs must be finite. Lists and matrices must be dense, without missing cells. Numeric lists allow at most 10000 entries, subject to the narrower lengths and code rules above. Extremely large composite outputs are rejected.

Alternative or Complementary methods

For a related step, use Sediment LC50 Calculator: A sediment LC50 concerns a lethal-concentration endpoint under a specified sediment assay. For a complementary comparison, use Plant EC50 Calculator: A plant EC50 concerns a defined effect at a stated concentration under an applicable assay.

References

Fish LC50 Calculator — tool.io

Similar or alternative tools

Sediment LC50 Calculator
A sediment LC50 concerns a lethal-concentration endpoint under a specified sediment assay.
Plant EC50 Calculator
A plant EC50 concerns a defined effect at a stated concentration under an applicable assay.