2-phosphonobutane-1,2,4-tricarboxylic acid

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

Study period:

1993-11-08 to 1993-11-11

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Remarks:

- no replicates per concentration level and controls - the algal medium is not explicitly described (most likely described in cited SOP)

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Version / remarks:

; directive 67/548/EEC (draft 1992)

Deviations:

yes

Remarks:

number of replicates is only 1, algae medium is not described in detail

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

yes

Remarks:

number of replicates is only 1, algae medium is not described in detail

Principles of method if other than guideline:

- number of replicates:
test item: 1 instead of 2
control: 1 instead of 3
- the algal medium is not described

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

All test concentrations, the control and the lowest and the highest concentration level without algae added were analysed, directly after start of the test and after 72 hours incubation time.

Vehicle:

no

Details on test solutions:

NA

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

- Scenedesmus subspicatus CHODAT
- Source: Pflanzenphysiologisches Institut der Universität Göttingen [University Göttingen, Germany. Institute for plant physiology]

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

NA

Hardness:

NA

Test temperature:

23°C+/-2°C

pH:

over all concentrations and control (t=0h): 7.9-8.2
over all concentrations and control (t=72h): 7.9-10.3

Dissolved oxygen:

NA

Salinity:

NA

Nominal and measured concentrations:

Nominal concentrations in mg/L.: 15.6; 31.3; 62.5; 125; 250; 500; 1000
Measured concentrations in mg/L (t=0h): 18.5; 33.0; 64.0; 127.5; 264.5; 494.5; 1112.0
Measured concentrations in mg/L (t=72h): 17; 33.5; 67.0; 137.0; 258.0; 513.5; 1049.5
Control in mg/L (t=0h): < 1.0
Control in mg/L (t=72h): < 1.0
Measured concentration of 15.6 mg/L without algae added (t=0h): 17.0
Measured concentration of 15.6 mg/L without algae added (t=72h): 17.0
Measured concentration of 1000 mg/L without algae added (t=0h): 1030.0
Measured concentration of 1000 mg/L without algae added (t=72h): 1061.5

Details on test conditions:

- Light intensity and quality: 120 µE/m2*s
- Determination of cell density and biomass at: 24; 48; 72 hours
- Medium: 100 mL
- Counting procedure: Microcellcounter Sysmex F-300

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

> 33.3 - < 65.5 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 1 081 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: biomass area

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

140 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: biomass aerea

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

17.8 mg/L

Conc. based on:

test mat.

Basis for effect:

cell number

Remarks on result:

other: DUNNETT test

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

33.3 mg/L

Conc. based on:

test mat.

Basis for effect:

cell number

Remarks on result:

other: DUNNETT test

Details on results:

NA

Results with reference substance (positive control):

NA

Reported statistics and error estimates:

DUNNETT test

No remarks.

Validity criteria fulfilled:

yes

Conclusions:

The results of the growth inhibition test of 2-phosphonatobutane-1,2,4-tricarboxylate acid in algae are: EC50 (biomass) > 140 mg/L and EC50 (growth rate) > 1081 mg/L. The EC10 (growth rate) is fount to be >33.3 mg/L and <65.5 mg/L.

Executive summary:

The results found in the growth inhibition test of 2-phosphonatobutane-1,2,4-tricarboxylate acid in algae are EC50 (biomass) > 140 mg/L and EC50 (growth rate) > 1081 mg/L. As this values are higher than 100 mg/L, no acute ecotoxicological hazard is indicated for algae (respective aquatic environment) even it is the most sensitive species (compared to daphnia and fish). The EC10 (growth rate) is fount to be >33.3 mg/L and <65.5 mg/L.

Description of key information

The results of the growth inhibition test of 2-phosphonobutane-1,2,4-tricarboxylic acid in algae is an 72h-ErC50 of > 1081 mg/L , an 72h-ErC10 of > 33.3 - < 65.5 mg/l and a NOEC of 17.8 mg/L, based on growth rate.

Key value for chemical safety assessment

EC50 for freshwater algae:

1 081 mg/L

EC10 or NOEC for freshwater algae:

33.3 mg/L