Registration Dossier

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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Endpoint summary

Administrative data

Description of key information


In a static test system a 96h-LC0 of ≥ 100 mg/L was determined on Brachydanio rerio (new name: Danio rerio) related to nominal concentration. As a consequence it can be concluded the 96h-LC50 is > 100 mg/L. The test was conducted according to EU Method C.1 (Acute Toxicity for Fish).


Daphnia magna was investigated in a semi-static test according to the OECD Guideline 202. No toxic effect was observed and a 48h-LC50 of >100 mg/L was received. The LC50-value relates to nominal concentration as the analytically determined values vary not more than 6.2 %.


According to OECD guideline 201 ' Alga, Growth Inhibition Test' the acute toxicity of dibutyl hydrogen phosphate to alga (Desmodesmus subspicatus) was tested. After 72 hours an ErC50 of >100 mg/L and ErC10 of 76 mg/L was received and a NOEC of 50 mg/L was calculated.

The lowest concentration 3.1 mg/L slightly dropped below the 80% recovery limit during the 72-hour exposure period. This is considered as not significant, because the highest determined concentration remained stable over the exposure time and therefore all results are expressed in terms of nominal concentrations.


To assess the toxicity of dibutyl hydrogen phosphate to microorganisms a study was conducted according to the OECD Guideline 209. Dibutyl hydrogen phosphate showed no respiration inhibition of activated sludge at a concentration of 10000 mg/L. The EC50 is higher than 10000 mg/L.

The effect value related to nominal concentration, since no analytical monitoring was performed.

Additional information

A testing proposal according to REACH Annex IX 9.1.5. ‘Long-term toxicity testing on invertebrates, (unless already provided as part of Annex VIII requirements)’ is included as a standard information requirement. The OECD TG 211 Daphnia magna Reproduction Test is regarded to be the most suitable test for addressing the information requirements. 


Additionally, a conditional testing proposal according to REACH Annex IX, 9.1.6. ‘Long-term toxicity testing on fish, (unless already provided as part of Annex VIII requirements)’ is included in the dossier as a standard information requirement and cannot be generated otherwise. The Fish Early Life Stage (FELS) toxicity test (OECD TG 210) is regarded as the most suitable test guideline for addressing the information requirements is included in the dossier based on BoA decisions A-010-2018 and A-011-2018. As the BoA decision A-010-2018 is currently being challenged before the General Court (T-656/20), we respectfully request ECHA to suspend any decision on the testing proposal and to first await the decision of the General Court in the aforementioned case. Vertebrate studies should always be the last resort to generate information.