Dihydrogen bis[P,P-dioctyl diphosphato(2-)-O'',O''''][hydroxyacetato(2-)-O1,O2]titanate(2-), branched and linear

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 - 25 May 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

Version / remarks:

2011

GLP compliance:

no

Remarks:

The study was conducted in full compliance with GLP guidelines with one exception. For more details please refer to field "Any other Information on Material and Methods incl. tables".

Test material

Test material information

1

Reference substance name:

Dihydrogen bis[P,P-dioctyl diphosphato(2-)-O'',O''''][hydroxyacetato(2-)-O1,O2]titanate(2-), branched and linear

EC Number:

271-571-3

EC Name:

Dihydrogen bis[P,P-dioctyl diphosphato(2-)-O'',O''''][hydroxyacetato(2-)-O1,O2]titanate(2-), branched and linear

Cas Number:

68585-64-8

Molecular formula:

not applicable (UVCB substance)

IUPAC Name:

({bis[(2-ethylhexyl)oxy]phosphoryl}oxy)[(2-{[({bis[(2-ethylhexyl)oxy]phosphoryl}oxy)(hydroxy)phosphoryl]oxy}-4-oxo-1,3-dioxa-2-titanacyclopentan-2-yl)oxy]phosphinic acid; {[({bis[(2-ethylhexyl)oxy]phosphanyl}oxy)({[({bis[(2-ethylhexyl)oxy]phosphoryl}oxy)(hydroxy)phosphoryl]oxy})[(2-hydroxyacetyl)oxy]titanio]oxy}({bis[(2-ethylhexyl)oxy]phosphoryl}oxy)phosphinic acid

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0 (control), 1.0, 10, and 100 mg/L
- Sampling method: samples were analyzed at 0 h (initiation) and from a composite of spent replicate solutions at 72 h (termination) of the test. At each sampling point, a 5-mL sample was collected from the control and each test substance treatment.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: The medium was prepared by the addition of appropriate reagent grade salts to autoclaved reagent water. Reagent water is produced by passing reverse-osmosis water through a series of deionization tanks, a laboratory water purification system consisting of carbon, demineralization, and organic adsorption cartridges, and then through a 0.2-μm filter. A 100 mg/L primary standard test item solution was prepared as water accommodated fraction (WAF) by weighing 0.1001 g of the substance and diluting in a glass bottle with 1.0 L of dilution medium. The solution was covered with black plastic to protect from light and stirred using a magnetic stir bar for approi. 24 h at room temperature, with the stirring adjusted to provide a vortex ≤25% of the solution depth. The bottle opening was covered with Parafilm® sealing film to prevent evaporation and contamination. When stirring was stopped, the solution settled for approx. 1 h prior to dispensing test treatment collections and then approximately 200 mL of the solution was drained and discarded. Appropriate volumes of the primary standard solution were then collected and diluted in 0.25 L of dilution medium to produce the 1.0 and 10 mg/L test solutions. The primary standard solution was used as the 100 mg/L test item solution.
- Controls: The control solution contained dilution medium only.
- Evidence of undissolved material: The control and all test solutions appeared clear and colorless with no visible particulates, surface film, or precipitate throughout the test.

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Test temperature:

22.8 to 25.3°C

pH:

pH at initiation: 6.4 to 7.7
pH at termination: 7.7 to 8.1

Nominal and measured concentrations:

Nominal Loading Rates: 0 (control), 1.0, 10, and 100 mg/L
Geometric mean measured concentrations: 0.00337, 0.0116, and 0.0538 mg/L of the diethylhexyl phosphite analytical marker

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 mL glass Erlenmeyer flasks
- Type (delete if not applicable): flasks were closed with foam stoppers
- Fill volume: 100 mL
- Initial cells density: 5.0 × 10^3 cells/mL
- Control end cells density: 144 × 10^4 cells/mL
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Freshwater algal medium (FWAM).

OTHER TEST CONDITIONS
- Photoperiod: continuous illumination
- Light intensity and quality: 8,000 ± 800 lux (cool-white fluorescent lighting)

EFFECT PARAMETERS MEASURED.
- Determination of cell concentrations: At 72 h (±1 hour), cell-count density was measured in all replicates of the control and test substance treatments by direct microscopic counting with a hemacytometer.

- Range finding study: yes, non-GLP but no further information given in the report.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

NOELR

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

WAF

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): yes
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: The control and all test solutions appeared clear and colorless with no visible particulates, surface film, or precipitate throughout the test.

Any other information on results incl. tables

ANALYTICAL RESULTS

Table 1: Analytical results.

Nominal Loading Rate Concentration [mg/L]	Measured Concentration as mg/L
	0 h	72 h	Geometric Mean Measured Concentration*
control	<MQL	<MQL	<MQL
1	0.000758	<MQL	0.00337
10	0.00899	<MQL	0.0116
100	0.0957	0.0303	0.0538

* For calculations, ½ MQL (0.000300 mg/L) used where the measured concentration was <MQL.

BIOLOGICAL RESULTS

Table 2: Growth Rate Values from Time Zero during a 72-h Exposure.

Nominal Loading Rate Concentration [mg/L]	Mean Growth Rate (cells/mL/hour)	% Inhibition
	72 h (%CV)	72 h
control	0.0784 (CV: 2)	-
1	0.0781 (CV: 3)	0
10	0.0790 (CV: 1)	-1
100	0.0767 (CV: 1)	2

No significant reduction in growth rate as compared to the control (Dunnett’s test, p = 0.05).

Further effect results:

- EyC50 > 100 mg/L

- EbC50 > 100 mg/L

- NOEbC = 100 mg/L

- NOEyC = 100 mg/L

VALIDITY CRITERIA

Table 3: Validity criteria for OECD 201.

Criterion from the guideline	Outcome	Validity criterion fulfilled
The biomass in the control cultures should have increased exponentially by a factor of at least 16 within the 72-hour test period.	280 times the initial nominal cell density	yes
The mean coefficient of variation for section-by-section specific growth rates (days 0-1, 1-2 and 2-3, for 72-hour tests) in the control cultures must not exceed 35%	not specified in report
The coefficient of variation of average specific growth rates during the whole test period in replicate control cultures must not exceed 7% in tests with Pseudokirchneriella subcapitata and Desmodesmus subspicatus. For other less frequently tested species, the value should not exceed 10%.	2%	yes

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

According to the authors the test was valid. For further details please refer to “Any other information on results incl. tables”.