Registration Dossier

Data platform availability banner - registered substances factsheets

Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Short-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

EC50 (48 h) = 52.1 mg/L for Daphnia magna (similar to OECD 202), recalculated value

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
52.1 mg/L

Additional information

For short-term toxicity to aquatic invertebrates, one GLP-study with 1,3,5-triazine-2,4,6(1H,3H,5H)-trithione, trisodium salt (TMT, CAS No. 17766-26-6) and one GLP-study with 1,3,5-triazine-2,4,6(1H,3H,5H)-trithione (TMT-H3, CAS No. 638-16-4) as read across of a surrogate substance are available.

This read across approach is in accordance with Regulation (EC) No 1907/2006, Annex XI, 1.5. "Grouping of substance and read across approach" and is explained within the read across justification in IUCLID section 13.

TMT-H3 is the acidic form of 1,3,5-triazine-2,4,6(1H,3H,5H)-trithione. Except for different cations (hydrogen vs sodium), the anion of both the source and target substance have an identical structure. Since dissociation of the sodium salt under environmental conditions (pH 4-9) yields the same ionic species as the acidic form of the substance, this read across can be considered as justified.


The first study was carried out according to OECD guideline 202, with TMT 60 as test substance (87-0023-DGO). The exposure of Daphnia magna resulted in an EC50 (24 h) of 1056 mg/L (nominal). This corresponds to 612.5 mg/L anhydrous TMT. During the study period the pH of the test solutions reached critical values up to 11.3 (pH of test solutions rose with increasing concentrations). A further deficiency of the study includes the lack of an analytical analysis of the test solutions. This would have been beneficial since test substance particles were seen in the test solutions containing the two highest test concentrations. It is recommended by OECD guideline 202, that “if the pH does not remain in the range 6 - 9, then a second test could be carried out, adjusting the pH of the stock solution to that of the dilution water before addition of the test substance. The pH adjustment should be made in such a way that the stock solution concentration is not changed to any significant extent and that no chemical reaction or precipitation of the test substance is caused”. But since a test with an adequate surrogate substance (TMT-H3) is available, it is not necessary to repeat the test.


Therefore a study with TMT-H3 (2007-0298-FGO), which is the acidic form of TMT, is taken into account for the chemical safety assessment of TMT. This read across study was conducted similar to OECD guideline 202 with analytical monitoring. Daphnia magna was exposed for 48 hours and the measured pH values ranged from 6.5 to 7.8 during the test period. An EC50 (48 h) of 38 mg/L (nominal) was determined. The measured concentrations were in the range from 95.2 to 106.1% of nominal values.


As aforementioned, with respect to the limitations of the study with TMT itself, the result for TMT-H3 (EC50 (48 h) = 38 mg/L) as a part of a read across approach was taken into account for further assessment. For this purpose the EC50 (48 h) value was recalculated to be 52.1 mg TMT/L.