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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Administrative data

Link to relevant study record(s)

Description of key information

Key value for chemical safety assessment

Additional information

In total, four study reports are available describing the effects of terphenyl mixtures on unicellular green algae, two of which are performed according to GLP principles. These two GLP studies on Santowax R (both K1) are the most recent algae studies and were performed without the use of a solvent to solubilize the test substance. The nominal concentrations were much higher than the solubilized fraction in those tests. The highest actual test concentration was 24.8 µg/l instead of the nominal concentration of 299 µg/l. No effects on growth rate were seen at this test concentration, thus the NOEC based on growth rate (72h) was above 24.8 µg/l. The NOEC for biomass in one of the tests was 3.22 µg/l (72h).

In the two other available studies (non-GLP) (K2), a solvent was used to improve the solubility of the substance (DMF or acetone). The actual concentrations were not measured in these studies and effects are thus expressed in nominal concentrations. The EC50 values (or ranges) are based on effects on biomass (96h) - not the REACH preferred endpoint - differed quite a lot between both studies (Therminol 88 (EC50 = 0.015 and 0.020 mg/L based on chlorophyl a and cell count respectively), Therminol 75 (EC50 = 0.103 mg/L based on cell count). This can be due to differences in composition between Therminol 88 and Therminol 75, but also differences in selected nominal concentrations (maximum conc of Therminol 88 was below the minimum conc of Therminol 75), or in solvent used.


The two studies on Santowax are clearly the most relevant and reliable studies since these are most recently performed according to the most recent guidelines. Additionally these studies assessed the appropriate REACH endpoint (growth rate, 72h) without using an additional solvent to improve the water solubility of the substance. Due to the fact that the other studies also provide valuable information, a Weight of Evidence approach was selected for these algae tests. For further risk assessment purposes, the test results from the study with Santowax R are selected. In this study the lowest NOEC value of 3.22 µg/l was reported.