Dodecyl laurate

Toxicity to aquatic algae and cyanobacteria

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)

Remarks:

Summary of available data used for the endpoint assessment of the target substance.

Adequacy of study:

key study

Justification for type of information:

Refer to the analogue approach justification provided in IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source: RA-A, CAS 3234-85-3, Evonik, 2012, P. subcapitata, 72 h

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 1.465 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source: RA-A, CAS 3234-85-3, Evonik, 2012, P. subcapitata, 72 h

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source: RA-A, CAS 3234-85-3, Evonik, 2012, P. subcapitata, 72 h

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

>= 1.465 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source: RA-A, CAS 3234-85-3, Evonik, 2012, P. subcapitata, 72 h

Duration:

72 h

Dose descriptor:

EL10

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source: RA-A, CAS 95912-86-0, BASF, 2013, D. subspicatus, 72 h

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

growth rate

Remarks on result:

other:

Remarks:

Source: RA-A, CAS 95912-86-0, BASF, 2013, D. subspicatus, 72 h

Conclusions:

The key values retained for the toxicity of the target substance to aquatic algae are an EL50 (72 h) of > 100 mg/L (nominal) corresponding to > 1.465 µg/L (meas. arith. mean), a NOELR (72 h) of ≥ 100 mg/L corresponding to ≥ 1.465 µg/L (meas. arith. mean), as well as an EL10 (72 h) and EL50 (72 h) of both > 1000 mg/L (nominal), based on experimental studies for two structurally and chemically similar source substances (OECD 201, P. subcapitata/D. subspicatus); read-across

Description of key information

No toxic effects up to the limit of water solubility (OECD 201, P. subcapitata), read-across

Additional information

There is no study available, in which the toxicity of lauryl laurate (CAS 13945-76-1) to aquatic algae was assessed. Therefore, read-across to the three structurally related source substances tetradecyl myristate (CAS 3234-85-3), fatty acids, C8-10, C12-18-alkyl esters (CAS 95912-86-0) and decyl laurate (CAS 36528-28-6) was performed in accordance with Regulation (EC) No 1907/2006 Annex XI, 1.5. The source substances are characterized by similar fatty acid and alcohol components and are therefore considered suitable representatives for the assessment of the toxicity of the target substance to aquatic algae. A detailed read-across justification is provided in the analogue justification in IUCLID section 13.

All three available studies were performed according to OECD guideline 201 and GLP.

In the study with the source substance tetradecyl myristate (CAS 3234-85-3) a static limit test was performed. Pseudokirchneriella subcapitata at an initial cell density of approximately 10000 cells/mL was exposed to a water accommodated fraction with a nominal limit loading rate of 100 mg/L for 72 h. GC/EI-MS analysis of the limit concentration resulted in a measured concentration of 0.142 µg/L (arithmetic mean) over the time of exposure.

After 72 h, no effects on growth rate and yield were observed, resulting in an EL50 of > 100 mg/L (nominal), corresponding to an arithmetic mean measured concentration of > 1.465 µg/L. The derived NOELR was ≥ 100 mg/L (nominal), corresponding to an arithmetic mean measured concentration of ≥ 1.465 µg/L. Hence, no toxicological effects on aquatic algae are expected up to the limit of water solubility.

In the second study with the source substance fatty acids, C8-10, C12-18-alkyl esters (CAS 95912-86-0), a static test was performed, in which Desmodesmus subspicatus at an initial cell density of 5000 cells/mL was exposed to five water accommodated fractions with nominal test item loading rates of10, 32, 100, 320 and 1000 mg/Lfor 72 h.

After 72 h, no effects on growth and yield were observed, resulting in an EL50 (72 h) > 1000 mg/L and a NOELR (72 h) ≥ 1000 mg/L. Therefore, no toxic effects on aquatic algae are expected up to the limit of water solubility.

The third experimental study for source substance octly laurate (CAS 36528-28-6) was performed according to OECD guideline 201 and GLP (Scymaris, 2017). In a static test, Pseudokirchneriella subcapitata was exposed to the five nominal test item concentrations of 0.125, 0.25, 0.5, 1.0 and 2.0 mg/L for 72 h. Since the test item was poorly soluble, a primary test item stock solution with a nominal concentration of 20 g/L was prepared in the solvent tetrahydrofuran. The final test solutions were prepared by dilution of this stock solution with culture medium. Therefore, solvent and dilution water controls were run in parallel. Effect values were determined and reported on the basis of the mean measured total concentrations, which were 0.075, 0.15, 0.27, 0.75, and 1.3 mg/L (53 – 75% of nominal concentrations). After 72 h, inhibition was less than 50% in both cases and no significant growth rate and yield inhibition was observed. Therefore, the ErC50 (72 h) and EyC50 (72 h) is considered to be greater than the highest concentration tested and is reported as > 1.3 mg/L. The reported NOEC is 1.3 mg/L for growth rate and yield inhibition and the ErC10 (72 h) and EyC10 (72 h) are both > 1.3 mg/L, respectively.

Based on the structural and chemical similarity of the target and source substances, the target substance is expected to exhibit a similar ecotoxicological profile as the selected source substances. Therefore, it can be concluded that the target substance lauryl laurate (CAS 13945-76-1) does not cause toxic effects to aquatic algae up to the limit of water solubility.