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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Reference
Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
REPORTING FORMAT FOR THE ANALOGUE APPROACH
Please refer to IUCLID Section 13.
Reason / purpose for cross-reference:
read-across source
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
32 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
135 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Remarks on result:
other: 127 - 143 mg/L
Key result
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
32 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Key result
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
81.3 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Remarks on result:
other: 72.7 - 89.8 mg/L

Description of key information

Algal growth inhibition: ErC50= 135 (127 – 143) mg/L; EyC50 = 81.3 (72.7 – 89.8) mg/L; NOEC = 32.0 mg/L

Key value for chemical safety assessment

EC50 for freshwater algae:
135 mg/L
EC10 or NOEC for freshwater algae:
32 mg/L

Additional information

Toxicity to algae of MHHPA was assessed from read across approach data available for the structural analogue 4-MHHPA as similar chemical and ecotoxicological properties were assumed.

Algal growth inhibitionto the unicellular freshwater green alga Pseudokirchneriella subcapitata was has been investigated according to OECD/EU test methods.4 –MHHPA was found to inhibit the growth after 72 hours exposure, EC50-values with 95 % confidence intervals for inhibition of specific growth rate (ErC50) and yield (EyC50) being 135 (127 – 143) mg/L and 81.3 (72.7 – 89.8) mg/L, respectively.

In accordance with ECHA guidance oninformation requirements and chemical safety assessment, Chapter R.7b: Endpoint specific guidance, the ErC50 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.