ToxicUnits Calculation

Version 2018.05

The TU-value (toxic unit) indicates the toxicity of each analytically detected substance by calculating its toxicity towards Daphnia magna.
TU-values, which are standardized to D. magna, are of advantage if a mixture of substances is present or if sampling sites with different mixtures of
toxicants should be compared.

Data Sources:

US EPA ECOTOX database:
Data processing: The median effect concentrations for repeatedly listed but identical studies of the same reference were calculated. Subsequently, all 48h LC50 values of Daphnia magna were extracted from the database, and in a final step median LC50 values for each CAS number were calculated.

IUPAC - Footprint Database:
A - EU Regulatory and Evaluation Data as published by EC and EFSA (DAR and Conclusion dossiers) / EU Annex III PIC DGD / EU MRL Database (website)
B - UK PSD ACP Evaluation Documents / and other DEFRA (UK) documents (website)
C - AGRITOX (website)
F - U.S. EPA ECOTOX Database (website) / U.S. EPA Pesticide Fate Database (website) / Miscellaneous WHO documents
J - Pesticide Action Network Database (website)
R - Peer Reviewed Scientific Publications

4 - Verified data
5 - Verified data used for regulatory purposes

TU> - the TU is higher than the calculated value due to a given LC50 > x

Concentration

The concentration (µg/L) of the respective substance i

Toxic Units

The TU value for each compound is based on the acute (48 h) LC50 of D. magna:

TU (D. magna) = log (Ci/LC50i)

where TU(D. magna) is the toxic unit of the substance i;
Ci is the concentration (µg/L) of the respective substance i;
and LC50i is the corresponding LC50 (48 h) of D. magna exposed to substance i (µg/L).