ECOTOX: how FairGrow fills the gaps in toxicity data
The European assessment of an active substance does not always give every value FairGrow needs. Then we look in ECOTOX, the public toxicity database of the US Environmental Protection Agency, and choose one value with fixed rules.
A public library of toxicity tests
The ECOTOX Knowledgebase is maintained by the US Environmental Protection Agency (EPA). It collects the results of toxicity tests from scientific publications: how much of a substance kills half of the fish in a tank, slows the growth of algae or stops water fleas from reproducing. It covers water organisms, soil organisms, bees, birds and mammals, and is updated four times a year.
The data is in the public domain. FairGrow downloads the complete database, keeps an unchanged copy and processes it on its own servers. For the September 2026 release that gave more than 300,000 test results for almost 1,000 active substances that occur in FairGrow.
European assessment first, ECOTOX second
For every active substance and every test, FairGrow first uses the value from the European assessment: the EFSA conclusions and the review reports of the European Commission. Only when that value is missing do we take a value from ECOTOX.
Is there no usable test anywhere? Then FairGrow uses the median of the substances with the same function, such as all fungicides, and labels it clearly as an assumption. A value from ECOTOX never replaces a European value.
Which tests count
Not every test in ECOTOX is comparable. FairGrow only uses tests that match the standard tests of the European assessment:
- standard species: rainbow trout, zebrafish or bluegill; the water flea Daphnia magna; the green algae Raphidocelis and Desmodesmus; duckweed; the earthworms Eisenia fetida and Eisenia andrei; the honey bee; bobwhite quail, mallard or quail; the rat;
- a test duration within 50% of the standard duration, for example 96 hours for fish (48 to 144 hours counts);
- units that can be converted unambiguously to mg per litre, mg per kg soil, micrograms per bee or mg per kg body weight;
- tests with the active substance itself. A test with a formulated product only counts when nothing else is available, and is then marked. A product with several active substances never counts.
One value from many tests
Often there are several valid tests. FairGrow then chooses the lowest valid value, as European risk assessment does: the most sensitive species and test decide. Next to it we keep the geometric mean of all valid values, so you can see how far the lowest value lies from the rest.
Some tests only give a limit, for example that more than 100 micrograms per bee did no harm. Such a limit only counts when there is no exact value, and it keeps its sign.
How certain a value is and what it means
Every chosen value gets a reliability. High: at least three tests from at least two publications. Medium: two tests. Low: one test, or only a limit. When the lowest value lies more than a factor 100 below the geometric mean, it may be an error or an exceptional test; our team then checks it by hand and records why a value was accepted or replaced.
To make a number readable, FairGrow translates it into a toxicity class: very high, high, moderate or low. The class follows the CLP limits for water organisms and common classifications for bees, earthworms, birds and mammals.
The class limits
| Group (end point) | Very high | High | Moderate | Low |
|---|---|---|---|---|
| Water organisms, short-term (LC50/EC50, mg/L) | up to 0.1 | 0.1 to 1 | 1 to 10 | above 10 |
| Water organisms, long-term (NOEC, mg/L) | up to 0.01 | 0.01 to 0.1 | 0.1 to 1 | above 1 |
| Honey bee (LD50, micrograms per bee) | up to 2 | 2 to 11 | 11 to 100 | above 100 |
| Earthworm, short-term (LC50, mg/kg soil) | up to 10 | 10 to 100 | 100 to 1,000 | above 1,000 |
| Earthworm, reproduction (NOEC, mg/kg soil) | up to 1 | 1 to 10 | 10 to 100 | above 100 |
| Birds and mammals (LD50, mg/kg body weight) | up to 10 | 10 to 50 | 50 to 500 | above 500 |
A limit value such as “more than 100” is never shown in a more toxic class than its number allows. The class describes the substance, not the risk of your spray: that also depends on dose, timing and distance to water.
Where you see it in FairGrow
- In the crop protection app: the block “Effect on the environment” per product, with the most sensitive active substance for each group of organisms.
- In the spray advice: a warning when a field borders water and the product is highly toxic to water organisms, when earthworms are at risk from repeated use of the same substance, and when the label says nothing about bees while the substance is very toxic to them.
- In the Pesticide Load: ECOTOX fills properties that the European assessment does not give, so fewer substances remain incomplete.
- In the risk profile of Harvest value: a separate indicator for the environmental pressure of your pesticide use, which does not count in the overall score.
What ECOTOX cannot do
Many studies that companies submit for authorisation are not public, so they are not in ECOTOX either. For earthworms, birds, mammals and water plants ECOTOX therefore has values for only a small share of the substances. Results from the literature also vary more than standardised regulatory studies.
That is why FairGrow shows the source and reliability of every ECOTOX value, why a European value always comes first, and why values from the European assessment are shown only as a class: their licence does not allow us to republish the numbers themselves. Every quarter FairGrow checks whether EPA has published a new release and then repeats the whole selection.
Source: US EPA ECOTOX Knowledgebase (public domain). Olker, J.H. et al. (2022). The ECOTOXicology Knowledgebase: a curated database of ecologically relevant toxicity tests to support environmental research and risk assessment. Environmental Toxicology and Chemistry 41(6): 1520-1539, doi 10.1002/etc.5324.
What is ECOTOX?
A public database of the US Environmental Protection Agency with results of toxicity tests from scientific literature, for water organisms, soil organisms, bees, birds and mammals. It is updated four times a year and is in the public domain.
Does an ECOTOX value replace the European assessment?
No. FairGrow always uses the European value first. ECOTOX only fills a property that the European assessment does not give.
Why the lowest value and not the average?
European risk assessment also starts from the most sensitive species and test. FairGrow shows the geometric mean next to it, so you can see whether the lowest value is an outlier.
Why do I sometimes see only a class and no number?
Values from the European assessment are shown as a class only, because their licence does not allow the numbers to be republished. ECOTOX values are public domain, so there you see the number, the species and the reference.
How often is the data updated?
FairGrow checks every four weeks whether EPA has published a new release. ECOTOX appears four times a year; after a new release the whole selection is repeated and manual checks by our team remain in force.
See the effect of a product
Open a product in the crop protection app and you see, per group of organisms, how toxic its active substances are and where each value comes from.
Open the crop protection app