Lauric acid

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

PNEC aqua (freshwater)

PNEC value:

0.13 mg/L

Assessment factor:

10

Extrapolation method:

assessment factor

PNEC freshwater (intermittent releases):

0.036 mg/L

Marine water

Hazard assessment conclusion:

PNEC aqua (marine water)

PNEC value:

0.013 mg/L

Assessment factor:

100

Extrapolation method:

assessment factor

STP

Hazard assessment conclusion:

PNEC STP

PNEC value:

912 mg/L

Assessment factor:

1

Extrapolation method:

assessment factor

Sediment (freshwater)

Hazard assessment conclusion:

PNEC sediment (freshwater)

PNEC value:

11.32 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Sediment (marine water)

Hazard assessment conclusion:

PNEC sediment (marine water)

PNEC value:

1.13 mg/kg sediment dw

Extrapolation method:

equilibrium partitioning method

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

PNEC soil

PNEC value:

2.19 mg/kg soil dw

Extrapolation method:

equilibrium partitioning method

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Conclusion on classification

Lauric acid is not classified to be hazardous to the aquatic environment according to EC 1272/2008 (self classification).

Reasons why no classification for lauric acid (C12 fatty acid) as “Acute Aquatic Hazard” is assigned

Lauric acid is considered to be ready biodegradable. The acute aquatic toxicity L(E)C50 values are > 1mg/L for fish, invertebrates and algae. Therefore, lauric acid does not need to be classified and labelled as acute aquatic hazard according to the ATP of the Regulation (EC) No. 1272/2008 (CLP).

Reasons why no classification for lauric acid (C12 fatty acid) as “Chronic Aquatic Hazard Category 3” is assigned

Lauric acid (C12 fatty acid, CAS 143-07-7) is a substance within the category of fatty acids (C4-C28). A detailed justification for the grouping of chemicals including read-across is provided in the Chemical Safety Report (CSR, see section 13 of the technical dossier).

All members of the mentioned fatty acids category are readily biodegradable and part of metabolic pathways in the test organisms Algae and Daphnia. The very fast decay of test concentration of C12 fatty acid in the test systems of Algae Growth Inhibition (OECD 201) and Daphnia Magna Reproduction (OECD 211) obviously leads to artefacts when standard methods are used to determine the corresponding NOECs and consequently to “unreliable” data for C&L decisions. In order to provide a more reliable data set for C&L decisions a test programme covering various fatty acids has been started in cooperation with Fraunhofer Institute IME (FhG) in Schmallenberg/Germany in 2012 (project outline 2015 see att 01 a/b FhG quotations). Based on these test programme the classification and labelling was reevaluated.

Algae toxicity:

Two studies on the toxicity of lauric acid to algae are available.

In the key GLP study (Ministry of the Environment of Japan, 2001) the toxicity toPseudokirchneriella subcapitatawas tested under static conditions according to OECD 201. After an incubation time of 72 hours EC50 and NOEC values were determined for the inhibition effects on the growth rate and biomass of algae: EC50s for both endpoints and the NOEC for growth rate were determined as > 7.6 mg/L (meas. initial), the NOEC for biomass was 4.4 mg/L.

A further GLP-study was conducted by Wierich and Kläs (1994) withDesmodesmus subspicatusaccording to DIN 38412, part 9 and resulted in an EC50 (72 h) value of > 100 mg/L (nominal) and an EC10(72 h) value of 57 mg/ L for growth rate, respectively.

Conclusion on algae toxicity

Results of NOEC/EC10 for C12 fatty acid above 1 mg/L indicates that no long-term aquatic classification is required on the basis of algae toxicity studies.

To verify the test concentration of fatty acids compounds, a new Algae Growth Inhibition study (OECD 201) under carefully controlled conditions with C8 fatty acid (octanoic acid, CAS 124-07-2) was conducted within the scope of the test programme already started in cooporation with Fraunhofer Institute IME (FhG) and revealed a NOEC of 17,5 mg/L (see att 02 FhG C8 fatty acid Algae Growth Inhibition study, OECD 201). This study performance showed that FhG succeeded to improve the test conditions with regards to controlled test substance concentrations.

Chronic Daphnia toxicity

In 2010, the long-term aquatic classification was proposed in accordance with the classification criteria of Regulation (EC) No. 1272/2008 (CLP, December 31, 2008) and the 1^stATP to the CLP (September 5, 2009). On the basis of the reliable data of “ready biodegradability” and “low potential of bioaccumulation (logKow < 4)”, no long-term aquatic classification was warranted to lauric acid. The endpoint of long-term invertebrate toxicity was covered by a Japanese study report (NITE 2001), where a NOEC < 1 mg/L was reported. But this value had no consequence on the classification decision at that time.  

 

After the publication of the 2^ndATP to the CLP regulation, NOEC values of chronic toxicity studies have been used as a matter of priority for the long-term aquatic classification. Thus, this test report has been reviewed again and severe deficiencies, such as invalid solvent control, no defined dose-response curve and unknown fate of the test substance has been stated. Particularly, the main problems are found due to unstable test substance concentration over test period under the test conditions. In some cases the concentration decayed to “non-detectable” in less than four hours. In order to cure the concentration instability daily concentration adjustments are made. These significant problems led to a change of the Klimisch score from 2 to 3. 

Therefore no reliable Daphnia Magna Reproduction study according to OECD 211 is considered to be currently available for C12 fatty acid. A new reliable study is consequently required in order to overcome methodological deficiencies due to rapid decay of the test substance and to verify the hazard assessment.

 

In the context of the ongoing test programm a new chronic daphnia toxicity test with a NOEC >= 1.3 mg/L has been reported already for decanoic acid (C10 fatty acid, CAS 334-48-5). This test result is currently used as read across to cover the daphnia chronic toxicity of C12 fatty acids, since a study with C12 fatty acid as such is under way within the scope of the test programme yet.

 

Conclusion on chronic Daphnia toxicity

·        The existing NITE (2001) study for C12 fatty acid with a NOEC < 1 mg/L has been devalidated (Reliability 3 , unreliable)

·        Chronic daphnia test with C10 fatty acid shows a NOEC > 1 mg/L.

·        Final results for C12 fatty acid from the testing programme are expected in 2015.

·        Consequently no classification is requiredon the basis of the read-across evidence. 

 

Main aims of ongoing test programme (att 01 a/b FhG project outline 2015)

·        Analysis of mass balance for the test substance including substance uptake via the food chain (Algae, Daphnia).

·        Understanding the “real” exposure to daphnia including the nutritional pathway.

·        Run a chronic daphnia study under better controlled conditions to determine a reliable NOEC for C&L decisions.

·        Establish a reliable dose-response curve

 

Overall conclusions

·        Currently available results of the test programme prove that test methodology for fatty acids can be improved in order to generate reliable experimental data

·        On the basis of available test results found so far, no classification is proposed for C12 fatty acid with regard to chronic aquatic hazard.  

 

Next steps

·        Test programme will be continued (see att 01 a/b FhG project outline 2015)

·        The Reach dossier for C12 fatty acid will be updated regularly every 6 months in order to reflect the results of the test programme.

 

Attachments in technical dossier section 13:

att 01 a/b        FhG project outline 2015

att 02             FhG C8 fatty acid Algae Growth Inhibition study OECD 201

All other study reports mentioned above are included in the technical dossier (section 6.1) as robust study summaries.