Triphenylphosphine oxide

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: original cited: "Algae inhibition test supported by the UBA (German environmental government agency) " resembling DIN 38412/9

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name: green algae
- Strain: SAG 86.81
ACCLIMATION
Culturing volume: 100 mL

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

20 °C

Nominal and measured concentrations:

Nominal concentrations: 0.976, 1.95, 3.9, 7.81, 15.62, 31.25, 62.5, 125 mg/L. A control was tested in parallel.
The stock solution was hardly soluble

Details on test conditions:

TEST SYSTEM
- Test vessel: Erlenmeyer flasks (nominal volume 250 mL) plugged with gas permeable silicon sponge caps
- Type: open
- Initial cells density: Initial count of algae cells/mL: 10000

GROWTH MEDIUM
- Standard medium used: yes; OECD Medium
Temperature: 20 °C
Culturing volume: 10 mL


TEST MEDIUM / WATER PARAMETERS
Test substance preparation: heating
- Culture medium different from test medium: no

Reference substance (positive control):

not specified

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: Recalculation (ToxRatPro v2.09)

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

6.04 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: Recalculation (ToxRatPro v2.09)

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

20.4 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: Recalculation (ToxRatPro v2.09)

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

9.81 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Recalculation (ToxRatPro v2.09)

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

14.366 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Recalculation (ToxRatPro v2.09)

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

29.644 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Recalculation (ToxRatPro v2.09)

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

7.812 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Recalculation (ToxRatPro v2.09)

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

3.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: Recalculation (ToxRatPro v2.09)

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

7.599 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: cell denstity

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

18.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: cell density

Duration:

72 h

Dose descriptor:

EC90

Effect conc.:

56.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: cell density

Details on results:

- Exponential growth in the control: no

Validity criteria fulfilled:

not specified

Conclusions:

The 72-hour EC10 and EC50 (growth rate) of the test item was determined to be 9.81 and 29.644 mg/L in nominal. The 72-hour EC10 and EC50 (biomass) of the test item was determined to be 6.04 and 20.4 mg/L in nominal.

Executive summary:

In a static 96-hour non-GLP test cited as "Algae inhibition test supported by the UBA (German environmental government agency) " resembling DIN 38412/9 with Desmodesmus subspicatus (SAG 86.81 strain) was exposed over duration of 96 hours to nominal test item concentrations of 0.976, 1.95, 3.9, 7.81, 15.62, 31.25, 62.5 and 125 mg/L. A negative control (OECD Medium only) was tested in parallel. Erlenmeyer flasks (nominal volume 250 ml, culturing volume: 10 mL) plugged with gas permeable silicon sponge caps were used. The initial count of algae was 10000 cells/mL. The test solutions were prepared by dilution of a stock solution of 125 mg test item/mL (highest concentration tested). The nominal effect concentrations related to growth rate (ErC) and biomass integral (EbC) were recalculated according to OECD TG 201 (adopted 23 Mar 2006), with ToxRatPro v2.09 using the fluorescence values for inhibition of biomass from the original report. Due to a non-logarithmic growth in the control, results of the growth rate are not suitable for classification. Hence, the biomass is considered to be relevant for classification (see validity criteria for recalculation from ECT (ToxRatPro v2.09)). The 72-hour EC10 and EC50 (biomass) of the test item was determined to be 6.04 and 20.4 mg/L in nominal.

Description of key information

The 72-hour EC10 and EC50 (growth rate) of the test item was determined to be 9.81 and 29.644 mg/L in nominal. The 72-hour EC10 and EC50 (biomass) of the test item was determined to be 6.04 and 20.4 mg/L in nominal.

Key value for chemical safety assessment

EC50 for freshwater algae:

20.4 mg/L

EC10 or NOEC for freshwater algae:

6.04 mg/L

Additional information

In a static 96-hour non-GLP test cited as "Algae inhibition test supported by the UBA (German environmental government agency) " resembling DIN 38412/9 with Desmodesmus subspicatus (SAG 86.81 strain) was exposed over duration of 96 hours to nominal test item concentrations of 0.976, 1.95, 3.9, 7.81, 15.62, 31.25, 62.5 and 125 mg/L. A negative control (OECD Medium only) was tested in parallel. Erlenmeyer flasks (nominal volume 250 mL, culturing volume: 10 mL) plugged with gas permeable silicon sponge caps were used. The initial count of algae was 10000 cells/mL. The test solutions were prepared by dilution of a stock solution of 125 mg test item/mL (highest concentration tested). The nominal effect concentrations related to growth rate (ErC) and biomass integral (EbC) were recalculated according to OECD TG 201 (adopted 23 Mar 2006), with ToxRatPro v2.09 using the fluorescence values for inhibition of biomass from the original report. Due to a non-logarithmic growth in the control, results of the growth rate are not suitable for classification. Hence, the biomass is considered to be relevant for classification (see validity criteria for recalculation from ECT (ToxRatPro v2.09)). The 72-hour EC10 and EC50 (biomass) of the test item was determined to be 6.04 and 20.4 mg/L in nominal. The 72-hour EC10 and EC50 (growth rate) of the test item was determined to be 9.81 and 29.644 mg/L in nominal.