Fatty acids, C14-18 and C16-18-unsatd., barium salts

Ecotoxicological Summary

Additional information

Read-across approach

There are no ecotoxicological data available for Fatty acids, C14-18 and C16-18-unsatd., barium salts and in the assessment of the ecotoxicity of fatty acids, C14-18 and C16-18-unsatd., barium salts, a read-across approach from data for barium is followed. This read-across strategy is based upon the assumption that i) upon release to the environment and dissolution in aqueous media, Fatty acids, C14-18 and C16-18-unsatd., barium salts will dissociate and only be present in its dissociated form, i.e. as barium cation and C14-18 and C16-18-unsatd. carboxylate anions and ii) toxicity is mainly caused by the liberated barium cations.

Upon dissolution in water, it is indeed predicted that metal carboxylates dissociate completely into the metal cation and the organic anion at environmentally relevant conditions. No information is available on the stability constants of Fatty acids, C14-18 and C16-18-unsatd., barium salts, but predictions of stability of other barium carboxylates (Ba propionate, Ba valerate and Ba isovalerate) in a standard ISO 6341 medium (2 mMCaCl₂, 0.5 mM MgSO₄, 0.77 mM NaHCO₃ and 0.077 mM KCl, pH 6 and 8) clearly show that monodentate ligands such as carboxylic acids have no potential for complexing barium ions in solution (< 1% of total metal concentration complexed at 0.001 mM Ba; Visual minteq. Version 3.0, update of 18 October 2012. http://www2.lwr.kth.se/English/OurSoftware/vminteq/index.html).

The fate and behaviour (e.g. partitioning) in the environment for Ba²⁺ and C14-18 and C16-18-unsatd. carboxylate anions are predicted to be significantly different from each other, resulting in a different distribution over the environmental compartments (water, air, sediment and soil). Because the relative exposure to both constituent ions is hence predicted to be different from the original composition of Fatty acids, C14-18 and C16-18-unsatd., barium salts, data for the ecotoxicological properties of Fatty acids, C14-18 and C16-18-unsatd., barium salts tested as such are considered less relevant for effects and risk assessment and a read-across approach to separate data for both the barium cation and C14-18 and C16-18-unsatd. carboxylate anions is preferred.

The substance fatty acids, C14-18 and C16-18-unsatd. is however not considered in the effects assessment for its barium salts because:

• The substance fatty acids, C14-18 and C16-18-unsatd. is not classified as dangerous under the EU CLP regulation (EC 1272/2008) and is no PBT or vPvB substances.
• The substance fatty acid, C14-18 and C16-18-unsatd. has a low exposure potential to the environment since it can be considered as readily biodegradable under aerobic conditions (EPI Suite 4.0, BIOWIN v4.10) and has a low solubility in water (< 1 mg/L)
• The acute toxicity to fish is low and no toxicity is expected at the solubility limit (Onitsuka et al., 1989, Chemosphere 18: 1621-1631).
• Fatty acids are generally not considered to represent a risk to the environment, which is reflected in their exemption from the obligation to register under REACH according to REACH Annex V, section 9 (Regulation (EC) No 987/2008).

For most metal-containing compounds, it is the potentially bioavailable metal ion that is liberated (in greater or lesser amounts) upon contact with water that is the moiety of ecotoxicological concern. The solubility of Fatty acids, C14-18 and C16-18-unsatd., barium salts (see IUCLID section 4.8 or chapter 1.3 of the CSR) is above the range of effects concentrations for dissolved barium in the aquatic environment (PNECfreshwater for Ba = 227.8 µg Ba/L) and therefore ecotoxicity data for soluble barium salts can be directly used in a read-across approach for Fatty acids, C14-18 and C16-18-unsatd., barium salts.

Conclusion on classification

The substance Fatty acids, C14 -18 and C16 -18 -unsatd., barium salts will dissociate into barium and C14-18 and C16-18-unsatd. carboxylate ions after dissolution in water and hence can be regarded as a mixture of both constituent ions. In the absence of toxicity data for Fatty acids, C14 -18 and C16 -18 -unsatd., barium salts itself, its classification for environmental hazards is based on the classification of its moieties (barium and fatty acids, C14-18 and C16-18-unsatd.). Both barium and fatty acids, C14-18 and C16-18-unsatd. are not classified as hazardous to the aquatic environment, and according to the summation method, it is therefore concluded that the substance Fatty acids, C14-18 and C16-18-unsatd., barium salts is not hazardous to the aquatic environment.