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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.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

Sediment toxicity

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Description of key information

The assessment of the sediment toxicity should be based on the outcome of aquatic toxicity testing. Pursuant to ECHA decision on a compliance check CCH-D-2114551285-49-01/F new studies with the registered substance will be conducted in the future. The finalised studies will be reported in an updated dossier until 22 July 2024 and the hazard assessment will be re-evaluated accordingly. Thus, the strategy of sediment toxicity will be evaluated later when all aquatic toxicity studies are available. For further details, please refer to the category concept document attached to the category object (linked under IUCLID section 0.2) showing an overview of the strategy for all substances within the glycol esters category.

Key value for chemical safety assessment

Additional information

The assessment of the sediment toxicity should be based on the outcome of aquatic toxicity testing. Pursuant to ECHA decision on a compliance check CCH-D-2114551285-49-01/F new studies with the registered substance will be conducted in the future. The finalised studies will be reported in an updated dossier until 22 July 2024 and the hazard assessment will be re-evaluated accordingly. Thus, the strategy of sediment toxicity will be evaluated later when all aquatic toxicity studies are available. For further details, please refer to the category concept document attached to the category object (linked under IUCLID section 0.2) showing an overview of the strategy for all substances within the glycol esters category.

No experimental data evaluating the toxicity to sediment organisms is available for fatty acids, C16-18, esters with ethylene glycol (CAS 91031-31-1). Since the substance is ready biodegradable, chronic exposure of sediment organisms is unlikely. Furthermore, the substance is not toxic to aquatic organisms up to the limit of water solubility. In addition, available data indicate, that fatty acids, C16-18, esters with ethylene glycol is not bioaccumlative. Based on the available information, toxicity to sediment organisms is not expected to be of concern.    

Intrinsic properties and fate 

Fatty acids, C16-18, esters with ethylene glycol is readily biodegradable (61% O2 consumption in 28 days; Richterich, 1998). According to the Guidance on information requirements and chemical safety assessment, Chapter R.7b, readily biodegradable substances can be expected to undergo rapid and ultimate degradation in most environments, including biological Sewage Treatment Plants (STPs) (ECHA, 2012b). Therefore, after passing through conventional STPs, only low concentrations of these substances are likely to be (if at all) released into the environment.    

Furthermore, the substance exhibits a log Koc of > 3 (MCI) and is poorly water soluble (< 0.05 mg/L at 20 °C; pH 5.94). The Guidance on information requirements and chemical safety assessment, Chapter R7.b (ECHA, 2012b) states that once insoluble chemicals enter a standard STP, they will be extensively removed in the primary settling tank and fat trap and thus, only limited amounts will get in contact with activated sludge organisms. Nevertheless, once this contact takes place, these substances are expected to be removed from the water column to a significant degree by adsorption to sewage sludge (Guidance on information requirements and chemical safety assessment, Chapter R.7a, (ECHA, 2012a)) and the rest will be extensively biodegraded (due to ready biodegradability). Thus, discharged concentrations of these substances into the aqueous/sediment compartment are likely to be negligible. Considering this one can assume that the availability of fatty acids, C16-18, esters with ethylene glycol in the sediment environment is generally very low, which reduces the probability of chronic exposure of sediment organisms in general.    Aquatic ecotoxicity data Acute aquatic toxicity tests of the substance to fish, invertebrates, algae and microorganisms showed no adverse effects occurred in the range of the water solubility of the substance (< 0.05 mg/L at 20 °C; pH 5.94). The obtained results indicate that fatty acids, C16-18, esters with ethylene glycol is likely to show no toxicity to sediment organisms as well.    Metabolisms/Bioaccumulation After absorption, fatty acids, C16-18, esters with ethylene glycol is expected to be enzymatically hydrolyzed by carboxylesterases yielding the corresponding alcohol and fatty acid. Fatty acids, C16-18, esters with ethylene glycol has a log Kow of > 6.27 (KOWWIN v1.68) indicating a potential for bioaccumulation. But due to the low water solubility, rapid environmental biodegradation and metabolisation via enzymatic hydrolysis, a relevant uptake and bioaccumulation in aquatic organisms is not expected. Enzymatic breakdown will initially lead to the free fatty acid and the free glycol alcohol (ethylene glycol). From literature it is well known, that these hydrolysis products will be metabolized and excreted in fish effectively (Heymann, 1980; Lech & Bend, 1980; Lech & Melancon, 1980; Murphy & Lutenske, 1990). This is supported by low calculated BCF values of 0.893 - 89.4 L/kg ww (BCFBAF v3.01, Arnot-Gobas, including biotransformation, upper trophic). Please refer to IUCLID Section 5.3 for a detailed overview on bioaccumulation of the Glycol Esters Category members. Thus, taking all information into account, the bioaccumulation of the category member fatty acids, C16-18, esters with ethylene glycol is assumed to be low.    

Conclusion 

Due to its readily biodegradable nature, extensive degradation of this substance in conventional STPs will take place and only low concentrations are expected to be released (if at all) into the environment. Once present in the aquatic compartment, further biodegradation will occur and, due to the high log Kow, low water solubility and high adsorption potential, fatty acids, C16-18, esters with ethylene glycol will be bioavailable to sediment organisms mainly via feed and contact with suspended organic particles. After uptake by sediment species, extensive and fast biotransformation of the substance by carboxylesterases into the free fatty acid and the corresponding alcohol is expected. The supporting BCF/BAF values estimated with the BCFBAF v3.01 program, Arnot-Gobas model including biotransformation, also indicate that this substance will not be bioaccumulative (all well below 2000). Furthermore, aquatic toxicity data show that no effects occur up to the limit of water solubility. Therefore, fatty acids, C16-18, esters with ethylene glycol is unlikely to pose a risk for sediment organisms in general and testing is thus omitted.  

For a detailed reference list please refer to the CSR.