Fatty acids, C16-18 (even numbered), aluminum salts

Bioaccumulation: aquatic / sediment

Description of key information

Bioaccumulation of fatty acids, C16 -18 (even numbered), aluminum salts in animals and biomagnification (i. e. accumulation and transfer through the food chain) is not considered relevant.

Key value for chemical safety assessment

BCF (aquatic species):

215 dimensionless

Additional information

No bioaccumulation tests in aquatic environment are available for fatty acids, C16-18 (even numbered), aluminum salts. Moreover, the Pow value could not be measured, since the substance has very low water solubility. Therefore in accordance to Regulation (EC) No. 1907/2006 Annex XI, 1.5 a read-across to another structurally related substance was conducted. Experimental bioconcentration data from a read-across substance, aluminium sulfate (CAS 10043-01-3) were used. The substance fatty acids, C16-18 (even numbered), aluminum salts, is produced from natural fatty acid materials which is a mixture of stearic (C18) and palmitic (C16) acid. The substance consists of up to 90% natural fatty acid and up to 10% of aluminum. Fatty acids, C16-18 (even numbered), aluminum salts, are present in water in dissociated form as different Al species and ionic fatty acid component. Due to very poor water solubility of the substance, the amount of dissolved Al will be very low (max. 5 μg/L). The fatty acid moiety is readily biodegradable and therefore it will undergo rapid and ultimate degradation in most environments. Besides, fatty acids are natural constituents of environment and are essential for a balanced nutrition of animals. Such compounds are naturally stored in the form of triacylglycerols primarily within fat tissue until they are used for energy production (fat storage tactic); it is therefore considered that there will be no risk to aquatic organisms from potential bioconcentration/ biomagnification of fatty acids. Therefore, read-across data from well soluble aluminium sulfate represent the worst case scenario for bioaccumulation of fatty acid, C16-18 (even numbered), aluminum salts in aquatic ecosystems.

A flow-through test investigating the bioaccumulation of aluminium (as aluminium sulfate) in fish Salvelinus fontinalis at different pHs (5.0, 6.0 and 7.2) was conducted (Cleveland 1991). Fish were exposed to 200 µg Al/L (nominal concentration in agreement with the measured values) for 56 days, followed by a 28-day depuration period. Mortality of fish and pH were monitored daily. A US EPA reference water, spiked samples and blank solutions were analyzed for quality assurance in the determination of Al in water samples. In result, 73% mortality was observed in the pH 5.3 group after exposure to Al, whereas effects were reduced at higher pH values: 48% at pH 6.1 and only 1% at pH 7.2.

The determined bioconcentration factors for Al were (whole body w.w.):

pH 5.3 : BCF = 215

pH 6.1: BCF = 123

pH 7.2: BCF = 36

In conclusion, bioaccumulation of fatty acids, C16-18 (even numbered), aluminum salts in animals and biomagnification (i. e. accumulation and transfer through the food chain) is not considered relevant.