Reaction products of diphosphorus pentaoxide and alcohol C7-9-iso, C8 rich, salted with 2-ethylhexylamine

Endpoint summary

Additional information

General considerations

The toxicity towards aquatic organisms of the target substance (Reaction products of diphosphorus pentaoxide and alcohol C7-9-iso, C8 rich, salted with 2-ethylhexylamine) was not investigated experimentally. Information about aquatic toxicity is available for the read-across substance (Phosphoric acid, mono- and di-(C8 -C10) ester, compds. with C12 - 14 amine), which serve as read-across approach to the target one. Both substances represent a mixture of mono- and (di) alkyl phosphates salted with an alkyl amine and thus the basic structures are the same (aliphatic ester of phosphoric acid and a primary aliphatic amine). Based on the similar structural characterisation, it can be assumed that also the similar mode of action in organisms will take place. For the detailed justification of this read-across approach, please refer to the corresponding statement by Chemservice S.A. (2013d).

 

A modification of the standard method for the preparation of aqueous test media was performed in the experiments since the substance was found to be poorly water soluble. An approach endorsed by several important regulatory authorities is to expose organisms to a Water Soluble Fraction (WSF) of the test substance. Thereby the aqueous media are prepared by mixing the test substance with water for a prolonged period of time (24 – 48 h). Afterwards, the test substance phase is separated by filtration and the test organisms exposed to the aqueous phase (WSF), which may contain the dissolved test substance and/or leachates from it. Exposures are expressed in terms of the original concentration in water at the start of the mixing period (loading rate) irrespective of the actual concentration in the WSF.

Toxicity to fish

Oncorhynchus mykisswas used as test organism in an experiment with the read-across substance Phosphoric acid, mono- and di-(C8 -C10) ester, compds. with C12 - 14 amine following OECD Guideline 201 (Wetton, 1999a). The exposure period was 96 h. The test concentrations were chosen as 0, 10, 18, 32, 56 and 100 mg/L loading rate WSF. A semi-static regime was employed involving a daily renewal of the preparations to ensure that the test concentrations remain near nominal and to prevent the building up of nitrogenous waste products. The LL₅₀(96h) was determined as 75 mg/L loading rate WSF with a 95 % confidence limit of 56 - 100 mg/L loading rate WSF. The NOEC(96h) is reported as 32 mg/L loading rate WSF. Long-term toxicity test results are not required in accordance with Annex VIII of REACH Regulation (EC) 1907/2006.

Toxicity to aquatic invertebrates

Experimental results regarding toxicity of the read-across substance (Phosphoric acid, mono- and di-(C8 -C10) ester, compds. with C12 - 14 amine) towards the freshwater invertebrateDaphnia magnaare available for exposure durations of 48 h (short-term) and 21 d (long-term). The short-term test was conducted according to OECD Guideline 202 (Wetton, 1999b). During this experiment, the test solutions were not renewed during the exposure period. Water samples were taken from all groups at start and termination of the test for Total Organic Carbon (TOC) analysis. A general trend for increasing carbon concentration with increasing loading rate was observed. The EC₅₀(48h) was determined as 16 mg/L loading rate WSF with 95 % confidence limits of 14 - 19 mg/L loading rate WSF. The NOEL was reported as 10 mg/L loading rate WSF.

The long-term toxicity effects of the read across substance (Phosphoric acid, mono- and di-(C8 -C10) ester, compds. with C12 - 14 amine) was evaluated according to OECD Guideline 202 (Wetton, 1999c). Four replicates of 10 daphnids per group were exposed to WSFs of 0.16, 0.50, 1.60, 5.0 and 16 mg/L loading rate for 21 days. The test solutions were renewed 3 times/week. Dissolved oxygen concentrations, pH and temperature were recorded before and after each test media renewal. As final results, the EL50(21d), based on immobilisation, was determined as 4.6 mg/L loading rate WSF (95 % CL: 3.9 - 5.6 mg/L loading rate WSF). Based on reproduction, the EL50(21d) was 3.5 mg/L (95 % CL: 3.2 - 4.0 mg/L loading rate WSF). The NOEL was given as 1.6 mg/L.

 

Toxicity to aquatic plant (algae)

The read-across substance (Phosphoric acid, mono- and di-(C8 -C10) ester, compds. with C12 - 14 amine) was investigated regarding its toxicity towards the freshwater green algaeScenedesmus subspicatusin accordance with OECD Guideline 201 (Mead, 1999b). The definitive test was performed with nominal loading rates of 5.0, 10, 20, 40 and 80 mg/L WSF, using three replicates per concentration. At the initiation of the experiment, the cell density was 10E4 cells/mL. The exposure time was 72 h under constant illumination and shaking at 24 +/- 1 °C. Algal samples were counted daily and Total Organic Carbon (TOC) analysis was performed at initiation and termination of the experiment. Based on the data obtained, the following results are reported: EbL₅₀(72h): 16 mg/L loading rate WSF (95 % CL: 13 - 20 mg/L loading rate WSF); ErL₅₀(72h): 32 mg/L loading rate WSF (95 % CL: 28 - 37 mg/L loading rate WSF); NOEL(72h): 5.0 mg/L loading rate WSF. Toxicity test results regarding any other aquatic plants are not required according to Annex VIII of REACH Regulation (EC) 1907/2006. 

 

Toxicity to aquatic microorganisms

An experiment with the read-across substance (Phosphoric acid, mono- and di-(C8 -C10) ester, compds. with C12 - 14 amine) was conducted according to OECD Guideline 209 to investigate the toxicity potential towards microorganisms in sewage treatment plants (STP) (Mead, 1999c). A mixed population of activated sludge microorganisms was sampled from the aeration stage from a predominantly domestic STP. The test solution was prepared by direct dispersion in water. 3,5-dichlorophenol was used as reference substance and confirmed the validity of the test system. The test concentrations for the definitive test were chosen as: 0, 100, 320, 1000, 3200 and 10000 mg/L. The rate of respiration was determined after 30 minutes and 3 hours contact time and gave as final results the following values: EC50(30min): 8200 mg/L and EC50(3h): 2100 mg/L. The NOEC was determined to be 320 mg/L.

 

Toxicity to other aquatic organisms

In accordance with Annex VIII of REACH Regulation (EC) 1907/2006 experimental investigations concerning other aquatic organisms are not required.