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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Long-term toxicity to aquatic invertebrates

Currently viewing:

Administrative data

Link to relevant study record(s)

Reference
Endpoint:
long-term toxicity to aquatic invertebrates
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
2017
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: A QSAR model, ECOSAR was used to estimate long-term toxicity to aquatic invertebrates
Justification for type of information:
QSAR prediction from reliable model
Qualifier:
no guideline required
Principles of method if other than guideline:
The QSAR model, Ecological Structure Activity Relationships (ECOSAR) Class Program was used to estimate the long-term toxicity to aquatic invertebrates. The following measured values were used in the model: log Kow = 4.33 and water solubility = 21.7 mg/L.
Test organisms (species):
Daphnia sp.
Water media type:
freshwater
Key result
Duration:
21 d
Dose descriptor:
other: chronic value (geometric mean of NOEC and LOEC)
Effect conc.:
1.662 mg/L
Key result
Duration:
21 d
Dose descriptor:
NOEC
Effect conc.:
1.175 mg/L
Details on results:
As per REACH Guidance Ch 10, a NOEC can be calculated from the chronic value by dividing the chronic by the square root of 2. Therefore, the calculated NOEC = 1.175 mg/L and will be used in the assessment.
Conclusions:
Using a reliable QSAR model, Ecological Structure Activity Relationships (ECOSAR) Class Program was used to estimate the 21d ChV for daphnids to be 1.662 mg/L.
Executive summary:

A reliable QSAR model (Ecological Structure-Activity Relationship (ECOSAR) version 1.11) was used to predict the chronic aquatic toxicity of 2 -butyloctanoic acid to daphnids. The 21 day chronic value (the geometric mean of the NOEC and LOEC) was 1.662 mg/L for the neutral organic class. As per REACH Guidance Ch 10, a NOEC can be calculated from the chronic value. Therefore, the calculated NOEC = 1.175 mg/L and will be used in the assessment as the key value for long-term toxicity to aquatic invertebrates.

Description of key information

The long-term toxicity of 2 -butyloctanoic acid was estimated using a QSAR model.  The 21 day ChV was 1.662 mg/L and the calculated NOEC was 1.175 mg/L.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates
Effect concentration:
1.175 mg/L

Additional information

No reliable experimental long-term toxicity studies with aquatic invertebrates are available for 2 -butyloctanoic acid. However reliable (Klimisch 2) modeled data are available and included in the dossier.

Sasol (2017) provided reliable (Klimisch 2) data for 2 -butyloctanoic acid using the QSAR model, Ecological Structure Activity Relationships (ECOSAR) Class Program to estimate long-term toxicity to aquatic invertebrates. The ECOSAR model estimates aquatic toxicity based on the structural similarity to chemicals for which aquatic studies are available. In addition, the log Kow and molecular weight of 2 -butyloctanoic acid are within the criteria (max log Kow = 7 for acute, 8 for chronic and max molecular weight = 1000) and domain of the model. The measured log Kow of 4.33 was used in the model. Model results indicate a 21 day chronic value (the geometric mean of the NOEC and LOEC) to be 1.662 mg/L using the baseline toxicity equation. As per REACH Guidance Ch 10, a NOEC can be calculated from the chronic value. Therefore, the calculated NOEC is 1.175 mg/L.