Phosphorous acid, mixed 2,4-bis(1,1-dimethylpropyl)phenyl and 4-(1,1-dimethylpropyl)phenyl triesters

Endpoint summary

Additional information

Testing was carried out on the following endpoints using the following guidelines:

Short-term toxicity to fish-OECD Guidelines for Testing of Chemicals (1992) No 203, "Fish, Acute Toxicity Test" referenced as Method C.1 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

 Fish, prolonged toxicity: 14-day study test;other guideline: Chemicals-Fish, prolonged toxicity: 14-day study test (GB/R 21808-2008).

Fish juvenile growth: 28-day study test;OECD Guideline 215 (Fish, Juvenile Growth Test) referenced as EU Method C.14 (Fish Juvenile Growth Test)

Short-term toxicity to aquatic invertebrates- OECD Guidelines for Testing of Chemicals (April 2004) No 202, "Daphniasp, Acute Immobilisation Test" referenced as Method C.2 of Commission Directive 92/69/(which constitutes Annex V of Council Directive 67/548/).

Long-term toxicity to aquatic invertebrates- OECD Guidelines for Testing of Chemicals No 211 (1998) "Daphnia magna, Reproduction Test", referenced as Method C.20 of Commission Regulation (EC) No. 440/2008.

Short-term toxicity to aquatic algae and cyanobacteria -OECD Guidelines for Testing of Chemicals (2006) No 201, "Freshwater Alga and Cyanobacteria, Growth Inhibition Test" referenced as Method C.3 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC).

Short-term toxicity to microorganisms -OECD Guidelines for Testing of Chemicals (1984) No 209 "Activated Sludge, Respiration Inhibition Test", Method C.11 of EEC Commission Directive 88/302/EEC and US EPA Draft Ecological Effects Test Guidelines OPPTS 850.6800.

The results of the studies are detailed below:

Short-term toxicity to fish

The 96-Hour LL*₅₀based on nominal loading rates was greater than 100 mg/l loading rate WAF and correspondingly the No Observed Effect Loading rate was 100 mg/l loading rate WAF.

It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/l.

Analysis of the freshly prepared test media at 0 and 72 hours showed measured test concentrations to range from 0.0054 to 0.192 mg/l. Analysis of the old or expired test media at 24 and 96 hours showed measured concentrations to range from less than the limit of quantitation (LOQ) of the analytical method, (which was determined to be 0.00044 mg/l) to 0.00981 mg/l. 

Given that the toxicity cannot be attributed to a single component or a mixture of components but to the test item as a whole, the results were based on nominal loading rates only.

*LL = Lethal Loading rate

 Fish, prolonged toxicity: 14-day study test

Under valid semi-static test conditions (72 h-renewal), the LOLC (the lowest observed lethal concentration), NOLC (the No observed lethal concentration), LOEC (the lowest observed effect concentration) and the NOEC (the No observed effect concentration) of the test substance were concluded as follows:

 14 d-LOLC > 100 mg/L WAFs (measured concentration 1.83 mg/L);

14 d-NOLC = 100 mg/L WAFs (measured concentration 1.83 mg/L);

14 d-LOEC (behaviours) > 100 mg/L WAFs (measured concentration 1.83 mg/L);

14 d-NOEC (behaviours) = 100 mg/L WAFs (measured concentration 1.83 mg/L);

14 d-LOEC (weights & length) > 100 mg/L WAFs (measured concentration 1.83 mg/L);

14 d-NOEC (weights & length) = 100 mg/L WAFs (measured concentration 1.83 mg/L).

No effects were noted at the limit of solubility in water.

Fish juvenile growth: 28-day study test

Under semi-static conditions of 72 h-renewal, the effect on growth rates and other observed effects in juvenile fish (Gobiocypris rarus) exposed to the test substance for 28 days was conducted.

The results showed that under valid semi-static test conditions (72 h-renewal), no fish died in control and treatments groups. Fish in all treatments and control groups were observed alive and appeared normal. ln the 28d test period, the LOEC (lowest observed effect concentration) and the NOEC (No observed effect concentration) of the test substance to juvenile rare minnow were concluded as follows:

28 d-LOEC > 100 mg/L WAFs (measured concentration 1.79 mg/L);

28 d-NOEC = 100 mg/L WAFs (measured concentration 1.79 mg/L).

No effects were noted at the limit of solubility in water.

Short-term toxicity to aquatic invertebrates

The 48-Hour EL*₅₀for the test material toDaphnia magnabased on nominal loading rates was greater than 100 mg/l loading rate WAF and the No Observed Effect Loading rate was 56 mg/l loading rate WAF.

Chemical analysis of the control and 1.0, 3.2, 10, 32 and 100 mg/l loading rate WAFs at 0 and 48 hours showed measured samples ranging from less than the Limit of Quantitation (LOQ) of the analytical method (which was determined to be 0.0024 mg/l) to 0.421 mg/l.

Samples of the control and 1.0, 3.2, 10, 32 and 100 mg/l loading rate WAFs were taken at 0 (fresh media) and 48 hours (old media) for Total Organic Carbon (TOC). Given the background level of carbon in the control vessels and also the low level of carbon in the test vessels, it was considered that all the results were around the limit of quantitation of the analytical method.

Therefore, given that toxicity cannot be attributed to a single component or a mixture of components but to the test material as a whole, and the dissolved test material was around the quantifiable limit of the analytical method, the results were based on nominal loading rates only.

The 48-Hour EC₅₀for the reference material toDaphnia magnabased on nominal concentrations was 0.78 mg/l with 95% confidence limits of 0.68 – 0.88 mg/l. The No Observed Effect Concentration was 0.32 mg/l.

*EL = Effective Loading rate

Long-term toxicity to aquatic invertebrates

The 21-Day EL*50 (immobilisation) value, based on nominal loading rates, for the parentalDaphniageneration (P1) was estimated to be greater than 100 mg/l loading rate WAF.

The 21-Day EL*50 (reproduction) value based on nominal loading rates was estimated to be greater than 100 mg/l loading rate WAF.

The "Lowest Observed Effect Loading rate" was considered to be greater than 100 mg/l loading rate WAF on the basis that at this loading rate no significant mortalities (immobilisation) were observed in the parental generation (P1) and that there were no significant differences (P>=0.05) between the control and the 100 mg/l loading rate WAF test group in terms of numbers of live young produced per adult by Day 21.

The "No Observed Effect Loading rate" was considered to be 100 mg/l loading rate WAF on the basis that at this loading rate there were no significant mortalities (immobilisation) observed in the parental generation (P1) and that there were no significant differences (P>=0.05) between the control and the 100 mg/l loading rate WAF test group in terms of numbers of live young produced per adult by Day 21.

Analysis of the freshly prepared test concentrations on Days 0, 5, 9 and 19 showed measured concentrations to range from less than the limit of quantitation (assessed as 0.00044 mg/l) to 0.0258 mg/l. Analysis of the old or expired media on Days 2, 7, 12 and 21 showed measured concentrations to range from less than the limit of quantitation to 0.0254 mg/l. The dissolved test item may have been one or several components of the test item. Given that toxicity cannot be attributed to a single component or mixture of components but to the test item as a whole, the results were based on nominal loading rates only.

Short-term toxicity to aquatic algae and cyanobacteria

Exposure ofDesmodesmus subspicatusto the test material gave EL*₅₀values of greater than 100 mg/l loading rate WAF and correspondingly the No Observed Effect Loading Rate was 100 mg/l loading rate WAF.

It was considered unnecessary and unrealistic to test at loading rates in excess of 100 mg/l.

Analysis of the test preparations at 0 hours showed measured test concentrations to range from 0.13 to 0.15 mg/l. A slight decline in measured test concentrations was observed at 72 hours in the range of 0.067 to 0.12 mg/l. This decline was in line with the preliminary stability analyses conducted which indicated that the test material was unstable in culture medium over the test period at a concentration of 0.10 mg/l.

Given that the toxicity cannot be attributed to a single component or a mixture of components but to the test material as a whole, the results were based on nominal loading rates only.

*EL = Effective Loading Rate

Short-term toxicity to microorganisms

The effect of the test material on the respiration of activated sewage sludge gave a 3‑Hour EC₅₀of greater than 320 mg/l. The No Observed Effect Concentration (NOEC) after 3 hours exposure was320mg/l.

The reference material gave a 3-Hour EC₅₀value of 7.9 mg/l, 95% confidence limits 6.1 - 10 mg/l.

Reliability

The above studies have all been ranked reliability 1 according to the Klimisch et al system. This ranking was deemed appropriate because the studies were conducted to GLP and were in compliance with agreed protocols, with no or minor deviations from standard test guidelines and/or minor methodological deficiencies, which do not affect the quality of relevant results.