Registration Dossier

Ecotoxicological information

Toxicity to terrestrial plants

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

The chemical safety assessment according to Annex I of Regulation (EC) No. 1907/2006 does not indicate the need to investigate further the toxicity to terrestrial plants

Key value for chemical safety assessment

Additional information

In accordance with Regulation (EC) No. 1907/2006, Annex X, Column 2, 9.4 further studies on the effects on terrestrial organisms do not have to be conducted since the chemical safety assessment indicates that there is no need.

Experimental data on the toxicity of fatty acids, C16-18 even numbered and C18-unsatd. triesters with propylidynetrimethanol (CAS 57675-44-2) to terrestrial plants are not available. Generally, all category members have a high adsorption potential. Exposure of plants to these substances is presumably very limited, since they are not expected to be found in the pore water in significant quantities, due to poor water solubility and high adsorption potential. Nevertheless in an early seedling growth toxicity test according to OECD 208 the effect of Fatty acids, C14-18 and C16-18 unsatd., triesters with trimethylolpropane (CAS 68002-79-9) on Lycopersicon esculentum, Raphanus sativus and Avena sativa was determined. The study reported no toxicity of the substance to the tested plant species (NOEC = 300 mg/kg for L. esculentum and R. sativus respectively, NOEC= 1000 mg/kg for A. sativa). Nevertheless this documentation is insufficient for an accurate assessment (only short abstract available) as it is not clear if this is related to phytotoxic or any physical effects hence it must be disregarded and the assessment for terrestrial toxicity can be based on the available terrestrial toxicity data for the polyol esters category.

A chronic exposure of terrestrial organisms is not probable since the TMP esters of the polyol esters category are readily biodegradable. Thus, they can be expected to be rapidly and ultimately degraded in the terrestrial environment. Two earthworm reproduction tests according to OECD 222 are available for the TMP esters 2-ethyl-2-[[(1-oxoheptyl)oxy]methyl]propane-1,3-diyl bisheptanoate (CAS 78-16-0) and 2-ethyl-2-(((1-oxoisooctadecyl)oxy)methyl)-1,3-propanediyl bis (isooctadecanoate) (CAS 68541-50-4). In both studies no chronic toxicity of the substances to Eisenia fetida was determined (Eisner, 2013). The substances caused neither mortality nor a decrease in body weight of adult earthworms. Also the reproduction rates were not affected by the TMP esters and thus a NOECmort/repro 1000 mg/kg was reported by both studies.

Based on the above mentioned available data, the terrestrial toxicity of the test substance is expected to be very low. Additionally, the substance is not expected to remain in the terrestrial environment, due to ready biodegradation. A relevant uptake and bioaccumulation in aquatic organisms is not expected due to the low water solubility, rapid environmental biodegradation and metabolisation via enzymatic hydrolysis. Enzymatic breakdown will initially lead to the free fatty acid and the free alcohol (e. g. trimethylolpropane). This is supported by low calculated BCF values of 0.89 – 0.91 L/kg ww (BCFBAF v3.01, Arnot-Gobas, including biotransformation, upper trophic). Since the hydrolysis products are supposed to be satisfactory metabolized in organisms, no potential for bioaccumulation is to be expected. For more information on the metabolism of enzymatic hydrolysis products please refer to IUCLID section 5.3, 6.3 or Chapter 4.3 Bioaccumulation.

In conclusion, the TMP esters group members and in particularfatty acids, C16-18 even numbered and C18-unsatd. triesters with propylidynetrimethanol (CAS 57675-44-2)is unlikely to pose a risk for terrestrial plants based on a) the lack of exposure and b) the low toxicity as expected for this substance for the terrestrial compartment based on the available experimental data, metabolism considerations and the lack of adverse effects in aquatic ecotoxicity tests.

In accordance with Regulation (EC) No. 1907/2006, Annex X, Column 2, 9.4 further studies on the effects on terrestrial organisms do not have to be conducted since the chemical safety assessment indicates that toxicity to terrestrial plants is not expected to be of concern.