Phosphoric acid, C4 and C12-14(even-numbered) Alkyl Esters, Ammonium Salts

Endpoint summary

Description of key information

Short-term toxicity to fish:

Oncorhynchus mykiss; OECD TG 203; read-across to 2-ethylhexyl analogue.

96-h LL50 value of greater than 100 mg/L loading rate WAF

Fathead minnows; OECD TG 203; read-across to Phosphoric acid, mono and bis-linear butyl esters, potassium salts

LC50 (96 h) value was determined to be 1300 mg/L

 

Short-term toxicity to aquatic invertebrates:

Daphnia magna; OECD 202; read-across to Phosphoric acid, mono and bis-linear butyl esters, potassium salts

The 24h and 48h EC50 value: > 100 mg/L (nominal)

The 48h No-Observed Effect Concentration (NOEC): 100 mg/L (nominal)

 Daphnia magna; OECD 202; read-across to Phosphoric Acid, C8-12 (even-numbered) linear Alkyl Esters

The 24h and 48h EC50 value: > 5.62 mg/L (measured)

The 48h No-Observed Effect Concentration (NOEC): 5.62 mg/L (measured)

 

Toxicity to aquatic algae:

Pseudokirchneriella subcapitata; OECD 201; read-across to Phosphoric acid, mono and bis-linear butyl esters, potassium salts

72h ErC50 value (biomass): > 100 mg/L (nominal)

72h EbC50 value (growth rate): > 100 mg/L (nominal)

72h EyC50 value (yield): > 100 mg/L (nominal)

72h NOEC: 100 mg/L (nominal)

72h LOEC: > 100 mg/L (nominal)

Pseudokirchneriella subcapitata; OECD 201; read-across to Phosphoric Acid, C8-12 (even-numbered) linear Alkyl Esters

Results based on initial nominal loading rates (WAFs):

72 -h ErL50 > 100 mg/L; 72 -h EγL50 = 37.8 mg/L; 72 -h EbL50 = 36.51 mg/L

72 -h NOErLR = 12.5 mg/L; 72 -h NOEγLR = 6.25 mg/L; 72 -h NOEbLR = 6.25 mg/L

Results based on initial measured concentrations:

72 -h ErC50 > 28.92 mg/L; 72 -h EγC50 = 15.70 mg/L; 72 -h EbC50 = 15.29 mg/L

72 -h NOErC = 6.53 mg/L; 72 -h NOEγC = 3.71 mg/L; 72 -h NOEbC = 3.71 mg/L

Additional information

Short-term toxicity to fish:

No study is available for Phosphoric acid, C4 and C12-14(even numbered) alkyl esters, Ammonium salts. 

Results are read across from studies performed on the 2-ethylhexyl- analogue and Phosphoric acid, mono and bis-linear butyl esters, potassium salts.

In an OECD TG 203 study performed on the 2-ethylhexyl- analogue, groups of 7 rainbow trout (Oncorhynchus mykiss) were exposed, in groups of seven, to a Water Accommodated Fraction (WAF) of the test item, at a single nominal loading rate of 100 mg/l for a period of 96 hours under semi-static test conditions. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 3 and 6 hours after the start of exposure and then daily throughout the test until termination after 96 hours. The 96-h LL50 based on nominal loading rates was > 100 mg/l loading rate WAF and correspondingly the No Observed Effect Loading rate was 100 mg/l loading rate WAF.

In a study equivalent or similar to OECD 203 fathead minnows were exposed to eight nominal concentrations of Phosphoric acid, mono and bis-linear butyl esters, potassium salts plus well-water as the control for 96 hours under static conditions. Ten fish were placed into the test chamber for each treatment group and the control group. Nominal concentrations of test item selected were 412, 588, 840, 1200, 1720, 2450, 3500 and 5000 mg/L. Verification of test item concentration was not performed. Clinical signs observed in fish exposed to ≥ 1200 mg/L included lying on the bottom, erratic swimming, swimming at the surface, darkening colouration, gasping for air and lethargy. The highest test concentration resulting in 0 % mortality was determined to be 588 mg/L and the lowest test concentration resulting in 100 % mortality was determined to be 1720 mg/L. The LC50 (96 h) value was determined to be 1300 mg/L.

 

Short-term toxicity to aquatic invertebrates:

 

No study is available for Phosphoric acid, C4 and C12-14(even numbered) alkyl esters, Ammonium salts. 

Results are read across from studies performed on Phosphoric Acid, C8-12 (even-numbered) linear Alkyl Esters and Phosphoric acid, mono and bis-linear butyl esters, potassium salts. Supporting data on the 2-ethylhexyl- analogue are also included.

 

Acute toxicity of the test item on Daphnia magna of Phosphoric acid, mono and bis-linear butyl esters, potassium salts was assessed in an Acute immobilisation test, over an exposure period of 48 hours in a static test system (OECD TG 202).

Because no toxic response was observed during the preliminary range-finding test, a Limit Test was carried out using only one test concentration (100 mg/L) and one control group in the definitive test.

The test concentration was analytically determined at the start and at the end of the experiment. Measured concentration was 105.3 mg/L at the start and 102.9 mg/L at the end of the experiment.

As the measured concentration deviated not more than 20 per cent from the nominal, biological results are based on the nominal concentration.

Twenty animals, divided into four groups (glass beaker) of five animals each were used at the test concentration and for the control.

All validity criteria were met during this study.

Under the conditions of this Daphnia magna acute immobilisation study the observed endpoints for the effect of the test item were as follows:

The 24h and 48h EC50 value: > 100 mg/L (nominal)

The 48h EC100 value: > 100 mg/L (nominal)

The 48h No-Observed Effect Concentration (NOEC): 100 mg/L (nominal)

The 48h Lowest Observed Effect Concentration (LOEC): > 100 mg/L (nominal)

 

Acute toxicity of Phosphoric acid, C8-12 (even numbered) linear alkyl esters on Daphnia magna was assessed in an Acute immobilisation test, over an exposure period of 48 hours in a static test system (OECD TG 202). Because no toxic response was observed during the preliminary range-finding test, a Limit Test was carried out using only one test concentration at the solubility level of the test item (100 mg/L nominal loading rate WAF) and one control group in the definitive test.

The test concentration was analytically determined at the start and at the end of the experiment. Measured concentration was 4.83 mg/L at the start and 6.55 mg/L at the end of the experiment, thus the corresponding measured geometric mean test item concentration was 5.62 mg/L. The biological results are based on the measured geometric mean test item concentration.

Twenty animals, divided into four groups (glass beaker) of five animals each were used at the test concentration and for the control.

All validity criteria were met during this study.

Under the conditions of this Daphnia magna acute immobilisation study the observed endpoints for the effect of Phosphoric acid, C8-12 (even numbered) alkyl esters were the followings:

The 24h and 48h EC50 value: > 5.62 mg/L (measured)

The 48h EC100 value: > 5.62 mg/L (measured)

The 48h No-Observed Effect Concentration (NOEC): 5.62 mg/L (measured)

The 48h Lowest Observed Effect Concentration (LOEC): > 5.62 mg/L (measured)

 

Toxicity to aquatic algae:

 

No study is available for Phosphoric acid, C4 and C12-14(even numbered) alkyl esters, Ammonium salts. 

Results are read across from studies performed on Phosphoric Acid, C8-12 (even-numbered) linear Alkyl Esters and Phosphoric acid, mono and bis-linear butyl esters, potassium salts. Supporting data on the 2-ethylhexyl- analogue are also included.

 

The effect of Phosphoric acid, mono and bis-linear butyl esters, potassium salts was assessed on algal growth using the unicellular green alga Pseudokirchneriella subcapitata, over an exposure period of 72 hours (OECD TG 201).

Because a toxic response was not observed during the preliminary concentration range-finding test, a Limit Test was carried out using only one test concentration of 100 mg/L (nominal) and one control group.

The test concentration was analytically determined at the start and at the end of the experiment. Measured concentration was 105.6 mg/L at the start and 106.3 mg/L at the end of the experiment. As the analytically measured concentration deviated not more than 20 per cent from the nominal, the biological results are based on the nominal test item concentration.

The test design included six replicates at test concentration and six replicates for the untreated control.

Statistical comparisons of biomass, average specific growth rates and yield in control and in treated groups were carried out using 2 Sample t-Test (α = 0.05) by TOXSTAT software.

The ErC50, EbC50 and EyC50 values of the test item were determined directly from the raw data.

Under the conditions of this algal growth inhibition test the calculated endpoints for the effect of the test item were the following:

72h ErC50 value (biomass): > 100 mg/L (nominal)

72h EbC50 value (growth rate): > 100 mg/L (nominal)

72h EyC50 value (yield): > 100 mg/L (nominal)

72h NOEC: 100 mg/L (nominal)

72h LOEC: > 100 mg/L (nominal)

 

The effect of Phosphoric Acid, C8-12 (even-numbered) linear Alkyl Esters was assessed on algal growth using the unicellular green alga Pseudokirchneriella subcapitata (Selenastrum capricornutum), over an exposure period of 72 hours (OECD TG 201).

A significant toxic response was observed during the preliminary range-finding test, therefore five test concentrations in a geometric series with a separation factor of 2.0 and one untreated control were tested in the main experiment.

The concentrations of test item used in the main experiment were: 6.25, 12.5, 25.0, 50.0 and 100.0 mg/L nominal loading rates WAFs. Test concentrations were analytically determined at the start of the test and at 24 hour intervals thereafter in order to better define loss of the test substance during the exposure period.

The test design included three replicates at each test concentration and six replicates for the untreated controls. There was an additional replicate without algae at each test concentration level for further analytical measurements (0, 24, 48 and 72 hours) in order to distinguish degradation and adsorption of the test item to algae.

According to the relevant guideline (OECD 201) disappearance of the test substance from solution by absorption to the increasing algal biomass does not mean that it is lost from the test system. When the result of the test was analysed, it was checked whether a decrease in concentration of the test substance in the course of the test was accompanied by a decrease in growth inhibition.

The corresponding measured geometric mean test item concentrations were: 1.78; 2.02; 8.95; 18.33 and 25.38 mg/L in presence of algae (more details are given in 4.2.). In addition, results of the analytical measurements of samples in absence of algae showed measured geometric mean test item concentrations of 3.46; 6.15; 11.99; 18.18 and 24.79 mg/L for the nominal concentrations of 6.25, 12.5, 25.0, 50.0 and 100.0 mg/L nominal loading rate WAFs respectively (more details are given in 4.2.).

However based on the section-by-section average specific growth rates, it is indicating that a decrease of concentration of the test item was not clearly accompanied by a decrease in growth inhibition. Based on these results most probably the test item is indeed absorbed to the increasing algal biomass, and should not be considered as lost from the test system.

Therefore it is recommended to express the EL50/EC50 and NOELR/NOEC//LOELR/LOEC values in the initial test item concentrations (nominal or measured) and not in the mean measured concentrations from the algae containing samples, thus biological results are related to the initial nominal loading rates (WAFs) and initial measured test item concentrations.

Results based on initial nominal loading rates (WAFs):

72 -h ErL50 > 100 mg/L; 72 -h EγL50 = 37.8 mg/L; 72 -h EbL50 = 36.51 mg/L

72 -h NOErLR = 12.5 mg/L; 72 -h NOEγLR = 6.25 mg/L; 72 -h NOEbLR = 6.25 mg/L

Results based on initial measured concentrations:

72 -h ErC50 > 28.92 mg/L; 72 -h EγC50 = 15.70 mg/L; 72 -h EbC50 = 15.29 mg/L

72 -h NOErC = 6.53 mg/L; 72 -h NOEγC = 3.71 mg/L; 72 -h NOEbC = 3.71 mg/L