Oxoaluminium, C16-C18-alkyl esters

Ecotoxicological Summary

Hazard for aquatic organisms

Freshwater

Hazard assessment conclusion:

no hazard identified

Marine water

Hazard assessment conclusion:

no hazard identified

STP

Hazard assessment conclusion:

no hazard identified

Sediment (freshwater)

Hazard assessment conclusion:

no hazard identified

Sediment (marine water)

Hazard assessment conclusion:

no hazard identified

Hazard for air

Air

Hazard assessment conclusion:

no hazard identified

Hazard for terrestrial organisms

Soil

Hazard assessment conclusion:

no exposure of soil expected

Hazard for predators

Secondary poisoning

Hazard assessment conclusion:

no potential for bioaccumulation

Additional information

Studies are available for short term toxicity to Daphnia, fish and algal growth for aluminum, benzoate C16-18-fatty acids complexes (Harlan 2013), which have been read across to the registered substance. These proprietary studies were conducted as Water Accommodated Fractions (WAF) at a GLP-compliant laboratory following OECD guidelines in standard water with a hardness of approximately 150 mg/L CaCO₃. No effects were seen in any of the tests at up to 100 mg/L (WAF) and the substance shows no toxicity at its limit of solubility.

Although the substance in isolated form (i.e. extracted from base oil) is considered readily biodegradable based on data read across from aluminium salts of benzoate and fatty acids C16-18 complexes, the substance tested as a 50% w.w. concentration in pharmaceutical white oil (representative of the substance in an inert carrier, typically base oil, the form in which it is marketed and used) is considered not readily biodegradable.

The substance will dissociate and degrade in the environment to CO₂, H₂O and, at pH7, insoluble hydrated aluminium oxide species. Equilibrium partitioning method could not be applied for this substance but while adsorption of hydrated aluminium oxide is possible, this is not expected to be hazardous as the aluminium species occur naturally in the environment.

The substance is not considered to bioaccumulate in the aquatic environment. The fatty acid components are either natural substances or chemically indistinguishable from natural substances with a long history of safe use in foods. Aluminium, with a BCF of 36 at pH 7.2 in freshwater fish, is also not expected to bioaccumulate.

The substance is not applied directly to soil and, furthermore, in realistic use scenarios, the aluminium thickener will be contained in base oil, with the formulated greases specifically designed to minimise the leaching of the thickener. Therefore, during use, the concentrations of the substance which would be released into the environment are further limited.

The substance is not expected to be bioavailable in the environment. The substance does not meet the criteria for environmental or human health classification and is not considered PBT/vPvB. As no hazard has been identified and there is no potential exposure, PNECs have not been derived.

Conclusion on classification

Based on read across, the substance is not expected to show acute toxicity to aquatic organisms at up to 100 mg/L (WAF) and therefore does not meet the criteria for classification as acutely toxic to the aquatic environment.

The substance is poorly soluble with no acute toxicity at levels up to the water solubility limit and is considered not readily biodegradable in the form in which it is marketed and used. However, it is not considered to meet the criteria for classification as chronic category 4 (the safety net classification) as it is not expected to bioaccumulate. The fatty acid components are either natural substances or chemically indistinguishable from natural substances with a long history of safe use in foods and the BCF for aluminium is 36, which is significantly below the BCF criteria of 500.

This is supported by the available data on the potential for chronic toxicity of the substance. Chronic aquatic toxicity data are only available for the structural analogue aluminium benzaoate C16-18 fatty acids complexes for algae (72 hour NOELR of 100 mg/L WAF) and these data would not result in a chronic classification.

The organic moieties of the substance, and the structural analogue Aluminum, benzoate C16-18-fatty acids complexes, are namely stearic acid, palmitic acid, benzoic acid and isopropyl alcohol (2-propanol). The organic moieties are known to have low toxicity to aquatic organisms and are not classified for the environment. Therefore, it is assumed that any potential for long-term ecotoxicity would be due to the Aluminium (Al) component of thesubstances. The available data show that, under reasonable, normal environmental conditions, Al will not cause a concern for chronic toxicity at concentrations below 74.4 μg/L. The ERGTC have generated data to show that the substance has a low water solubility of ≤ 12.5 µg/L at 20°C based on total Al concentration and, therefore, is unlikely to occur in water at concentrations high enough to cause a toxicity concern.

Furthermore, the substance is not used in isolated form but as a grease thickener within base oil. The ERGTC have conducted leaching studies in deionised water which show that, when present within a grease base, the grease thickeners are not bioaccessible. The leaching studies used a concentration of base grease (thickener in a base oil to form a grease matrix) of 1000 mg/L, with the substance being present at 50% in medicinal white oil. In the leaching studies, no Al was detected in water at the limit of detection of the analytical method of 5 µg/L. The substance would therefore not be expected to cause a concern for chronic toxicity.The screening ecotoxicity data in the leaching studies, using SPME-GC and the in vitro Microtox assay, confirm a lack of toxicity of the greases.

This substance has been registered by a Member of the European REACH Grease Thickeners Consortium (ERGTC). A number of decisions have been made in the dossier with regard to the approach taken for registering the substance including the testing strategy and the justification for waiving certain endpoints. Several of the decisions reflect the technical difficulties of testing the substance and the relevance of data with regard to the potential for exposure, given that the substance typically occurs in situ in base oil. A face to face meeting between the ERGTC and ECHA was held in Helsinki on 8th September 2016 which discussed many of these topics and a copy of the minutes from the meeting are attached to the dossier (See section 13 of IUCLID). Therefore, if there are any queries or concerns which arise when the dossier is reviewed, it is requested that the reviewer discuss these with the ERGTC ([e-mail]) as there may be background information and previously discussions between the ERGTC and ECHA available which are relevant.