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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

To assess potential effects of methyl 2-hydroxyisobutyrate to the freshwater green alga, Pseudokirchneriella subcapitata, an Alga Growth Inhibition Test according to OECD Testing Guideline 201 was performed for 72 hours with target concentrations of 0 (AAP control), 1.00, 3.10, 9.80, 31.3 and 100 mg methyl 2-hydroxyisobutyrate/L. Cell density was determined at approximately 24, 48 and 72 hours (±1 hour from test initiation).

The acute toxicity values for Pseudokirchneriella subcapitata exposed to methyl 2-hydroxyisobutyrate over a 72-hour static exposure period and based on nominal concentrations were as follows:

Growth rate

72-hour ErC50: >100 mg/L (highest concentration tested)

72-hour ErC20: 95.6 mg/L (95% C.I. = 84.1 – 109 mg/L)

72-hour ErC10: 45.4 mg/L (95% C.I. = 36.1 – 57.1 mg/L)

72 -hour NOEC: 9.80 mg/L

Cell yield

72-hour EyC50: 54.8 mg/L (95% C.I. = 44.1 – 68.2 mg/L)

72-hour EyC20: 20.8 mg/L (95% C.I. = 13.5 – 32.1 mg/L)

72-hour EyC10: 12.5 mg/L (95% C.I. = 7.03 – 22.3 mg/L)

72-hour NOEC: 9.80 mg/L

Key value for chemical safety assessment

EC50 for freshwater algae:
100 mg/L
EC10 or NOEC for freshwater algae:
9.8 mg/L

Additional information

Temperatures during the exposure period ranged from 22-23°C. The pH ranged from 7.3-7.8 and the light intensity ranged from 4680-5520 lux. Test solutions were analyzed for methyl 2-hydroxyisobutyrate concentrations at test initiation and exposure termination by gas chromatography with selected ion monitoring (GC/SIM). None of the analyses of the AAP medium control exhibited a concentration exceeding the lower limit of quantitation (LLQ) equivalent to 0.125 mg methyl 2-hydroxyisobutyrate/L. Measured concentrations of methyl 2-hydroxyisobutyrate ranged from 83.2 to 104% of nominal concentrations over the course of the exposure period. The resulting mean measured test concentrations were 0.959, 2.99, 8.92, 28.7 and 91.2 mg methyl 2-hydroxyisobutyrate/L. Because the mean measured concentration were within ± 20% of the target nominal concentrations, study endpoints were based on nominal concentrations.