Amides, C8-18 (even numbered) and C18-unsatd., N-(hydroxyethyl)

Endpoint summary

Description of key information

Hydrolysis

The study does not need to be conducted because the substance is readily biodegradable.

 

Biodegradation in water

Under the study conditions, the test substance was considered to be readily biodegradable.

 

Biodegradation in water and sediment

In accordance with column 2 of Annex IX of the REACH regulation, testing for this end point is scientifically not necessary and does not need to be conducted since the test chemical is readily biodegradable in water.

 

Biodegradation in soil

In accordance with column 2 of Annex IX of the REACH regulation, testing for this end point is scientifically not necessary and does not need to be conducted since the test chemical is readily biodegradable in water.

 

Bioaccumulation: aquatic / sediment

On the basis of the experimental studies of the test chemical and applying the weight of evidence approach, the BCF value of the test chemical can be expected to be in range of 29 to 190, respectively. Thus, as this value does not exceed the bioconcentration threshold of 2000 indicating that the test chemical is not expected to bioaccumulate in the food chain.

 

Adsorption / desorption

The average Koc value of 1469 was retained for risk assessment purposes.

Additional information

Hydrolysis

The study does not need to be conducted because the substance is readily biodegradable.

 

Biodegradation in water

A study was conducted to determine the ready biodegradability of the test substance, C8-18 and C18-unsatd. MEA, according to OECD Guideline 301B (CO2 evolution test), in compliance with GLP. A mineral medium, corresponding to 10-20 mg total organic carbon (TOC)/L, was inoculated with activated sludge (30 mg d.s./L). The test vessels were aerated by the passage of CO2-free air and incubated under aerobic conditions for 28 d. Degradation was followed by determining the CO2 produced and absorbed to sodium hydroxide via IC-measurement on Days 3, 6, 10, 14, 21 and 28 of the study. The reference substance used was sodium benzoate at a concentration of 20 mg/L organic carbon. The reference substance reached the pass levels for ready biodegradability within 3 d. The mean degradation extent of the test substance was 88.3% within 28 d after acidification (mean value of three test vessels). Under the study conditions, the test substance was considered readily biodegradable (Kronenberger-Schäfer, 2008).

A study was conducted to determine the ready biodegradability of the test substance, C8-18 and C18-unsatd. MEA, according to OECD Guideline 301B (CO2 evolution test). The test (20 mg C/L) and reference (sodium benzoate) substances were incubated with activated sludge and observed for degradation by measurement of the theoretical amount of carbon dioxide (ThCO2) over a 28 d period. The reference substance, sodium benzoate reached 10% biodegradation after Day 2 and > 60% after Day 10. It met the validity criteria established in the guideline for a reference substance. Biodegradation of the test substance on Day 28 equalled 99%. Under the study conditions, the test substance was considered to be readily biodegradable (Mead, 1997).

 

Biodegradation in water and sediment

In accordance with column 2 of Annex IX of the REACH regulation, testing for this end point is scientifically not necessary and does not need to be conducted since the test chemical is readily biodegradable in water.

 

Biodegradation in soil

In accordance with column 2 of Annex IX of the REACH regulation, testing for this end point is scientifically not necessary and does not need to be conducted since the test chemical is readily biodegradable in water.

 

Bioaccumulation: aquatic / sediment

Data available for its read across chemicals has been reviewed to determine the bioaccumulation potential of the test chemical. The studies are as mentioned below:

 

Bioaccumulation study was conducted on test organism Cyprinus carpio for 31 d for evaluating the bioconcentration factor (BCF value) of test chemical. The study was performed according to other guideline "Bioaccumulation test of a chemical substance in fish or shellfish" provided in "the Notice on the Test Method Concerning New Chemical Substances", respectively. Cyprinus carpio was used as a test organism for the study. Test chemical was prepared in HCO-40. Test chemical nominal conc. used for the study was 0.0848 mg/l and 0.00848 mg/l, respectively. Range finding study involve the LC50(96h) > 15.3 mg/L on Rice fish (Oryzias latipes). TThe bioconcentration factor (BCF value) of test chemical on Cyprinus carpio was determined to be 150 L/Kg at a conc. of 0.0848 mg/l and 190 L/Kg at a conc. of 0.00848 mg/l, respectively, which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is not expected to bioaccumulate in the food chain.

 

Another bioaccumulation study in fishwas conducted for estimating the BCF (bioaccumulation factor) value of test chemical. The bioaccumulation factor (BCF) value was calculated using a water solubility of 226 mg/l and a regression-derived equation. The estimated BCF (bioaccumulation factor) valueof test chemical was determined to be 29 dimensionless, which does not exceed the bioconcentration threshold of 2000, indicating that the test chemical is considered to be non-accumulative in aquatic organisms.

 

On the basis of the experimental studies of the test chemical and applying the weight of evidence approach, the BCF value of the test chemical can be expected to be in range of 29 to 190, respectively. Thus, as this value does not exceed the bioconcentration threshold of 2000 indicating that the test chemical is not expected to bioaccumulate in the food chain.

 

Adsorption / desorption

The soil adsorption and desorption potential (Koc) of the test substance, C8-18 and C18-unsatd. MEA, was estimated using the Molecular Connectivity Index (MCI) and Log Kow methods of the KOCWIN v 2.01 program (EPISuite v 4.11). Since the test substance is an UVCB, the Koc values were estimated for individual constituents using SMILES codes as the input parameter. Using the MCI and log Kow methods, the predicted Koc values for all the constituents were estimated to range from 21.37 to 8636 L/kg and 15.71 to 8165 L/kg respectively. The corresponding log Koc values ranged from 1.32 to 3.93 and 1.19 to 3.91 (US EPA, 2019). This indicates a negligible to moderate adsorption potential (US EPA, 2012). Since not all constituents meet the MW and structural fragment molecular descriptor domain criteria as defined in KOCWIN v 2.01 user guide of EPI Suite TM, the Koc predictions were considered to be less accurate. Given that the constituents are structurally very similar and vary only in the carbon chain length, a weighted average value, which considers the percentage of each constituent in the substance, was calculated to dampen the errors in predictions. The weighted average Koc (log Koc) values were calculated as1625.52 L/kg (log Koc=3.21) and 1312.66 L/kg (log koc= 3.11), using the MCI and log Kow methods respectively. Based on the above information, the test substance is expected to have a moderate adsorption potential (US EPA, 2012) to soil and sediment, leading to slow migration to ground water. Overall, the KOC predictions for the test substance using KOCWIN model of EPI Suite TM can be considered to be reliable with moderate confidence.

The average Koc value of 1469 was retained for risk assessment purposes.

Furthermore, after discussion with ECHA in the frame of a Dossier Improvement Action Plan (DIAP), Koc testing according to OECD Guideline 106 is planned with the read across substance C16 MEA in order to support the modelling results obtained with EPISuite across all MEA-FAA substances.