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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Additional information

The 48–hour acute toxicity of a structural analogue, tetrahydromethylphthalic anhydride (MTHPA), to Daphnia Magna was studied under static conditions. Daphnids were exposed to control and test chemical at nominal concentration of 0, 32, 56, 100, 180, 320 mg/L for 48 hours. Mortality/immobilisation and sublethal effects were observed daily. The 48 – hour LC50/EC50 was 130 mg /L. The 48 – hr NOEC based on immobilisation was 87 mg/L.


In a 72 hour study, the cultures of Selenastrum capricornutum were exposed to an analogue of the substance, tetrahydromethylphthalic anhydride (MTHPA), at nominal concentrations of 10, 18, 32, 56 and 100 mg/L under static conditions in accordance with OECD Guideline 201. An EC50 of 68 mg/L (growth rate) and 64 mg/L (biomass) were reported and the NOEC value determined was 27.5 mg/L (growth rate and biomass).In accordance with ECHA guidance oninformation requirements and chemical safety assessment,Chapter R.7b: Endpoint specific guidance, theErC50 endpoint is used in DNEL derivation. This is because use of values based on biomass cannot be applied to an analysis of results from a system in exponential growth without logarithmic transformation.