Phosphinic acid

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Justification for type of information:

Justification of the read across:
In the current assessment, data from sodium phosphinate were used to evaluate the phosphinic acid properties. Phosphinic acid is commercially prepared as the result of pH adjustement of the sodium phosphinate salt. The main assumption is that sodium is not significant in respect of all the properties under consideration which are expected to be related to the phosphinate anion. In dilute aqueous conditions of environmental pH (5-9) the salt will behave no differently to the parent acid, at identical concentration of the particular speciated form present and will be fully dissociated. For the aquatic hazard assessment, some tests were performed on monohydrate salt and the results on measured active compounds (phosphinate) are expressed on phosphinic acid to be used for the purpose of risk assessment and classification and labelling. Therefore the read across approach is applied in the present dossier.

Reason / purpose for cross-reference:

read-across source

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Reference substance (positive control):

yes

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- In the control and at the test concentration of 100 mg/L, no immobilized test organisms were observed during the test period of 48 hours.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: None

No more data available

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

from 1995-02-06 to 1995-02-23

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Guideline study with acceptable restrictions. The study follows the OECD Guideline 202, but there is no data regarding GLP compliance and no analytical monitoring has been performed to check the stability of the substance during the test. However, the two validity criteria are fulfilled.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

: no analytical monitoring on the test substance.

GLP compliance:

not specified

Analytical monitoring:

not specified

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: direct dispersion in water
- Eluate: reconstituted water
- Controls: 2 controls without the tested substances (negative controls)

Test organisms (species):

Daphnia magna

Details on test organisms:

No data

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

the reconstituted water has an approximate theoretical total hardness of 270 mg/L as CaCO3

Test temperature:

temperature was maintained at 21 °C throughout the study

pH:

pH changes during the study from:
- 7.8 to 7.7 in control sample
- 5.3 to 6.6 in test sample

Dissolved oxygen:

changes during the study from:
- control: 8.7 to 8.2 mg of 02 /L
- test sample: 8.7 to 8.2 mg of 02 /L

Nominal and measured concentrations:

0 (control) and 100mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open / closed: no data
- Material, size, headspace, fill volume: test vessels of 250 ml containing 200ml of test solution
- Aeration: the reconstituted water was aerated until the dissolved oxygen concentration was approximately air-saturation value during definitive study. During the test, no auxiliary aeration
- Renewal rate of test solution (frequency/flow rate): none
- No. of organisms per vessel: 10
- No. of vessels per concentration: 4 replicates
- No. of vessels per control: 2 replicates

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water as recommended in the guideline OECD 202.
- Conductivity: < 5µS.cm-1
- pH equal to 7.8 +/- 0.2 adjusted (if necessary) with NaOH or HCl
- Culture medium different from test medium: no data
- Intervals of water quality measurement: measurement performed at 0; 24 and 48 hours.

OTHER TEST CONDITIONS (see table 1 in freetext):
- Adjustment of pH: no (there were concentration dependant differences in pH observed throughout the study)
- T°: Temperature was maintained at 21°C throughout the study
- Oxygene: no treatment related differences

EFFECT PARAMETERS MEASURED : inspection to cumulative immobility (in Definitive study) and the cumulative mortality (in Range-finding study) at 2;4 and 48 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: no relevant, limit test
- Range finding study: 0; 0,10; 1; 10; 100 (spacing factor: 10)
- Test concentrations: 100 mg/L
It was considered unnecessary and unrealistic to test at concentrations in excess of 100mg/L
- Results used to determine the conditions for the definitive study: No cumulative mortality (initial population of 10) at 24h and 48 h in the range-finding study for 0; 0.10; 1.0; 10; 100 mg/L of tested substance.

Reference substance (positive control):

not specified

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: immobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: immobility

Details on results:

- Mortality of control: no.
No more data available

Reported statistics and error estimates:

none

Table 2: Cumulative Immobilisation data for Daphnia magma exposed for 48 hours to phosphinic acid 50%.

Concentration mg/L	Cumulative immobilised Daphnia (Initial population: 10 per replicate)
	24 hours			48 hours
	No per replicate	Total	%	No per replicate	Total	%
Control	R1	0	0	0	0	0
	R2	0	0	0	0	0
100	R1	0	0	0	0	0
	R2	0	0	0	0	0
	R3	0	0	0	0	0
	R4	0	0	0	0	0

Validity criteria fulfilled:

yes

Remarks:

For details see overall remarks above freetext

Conclusions:

In the test conditions phosphinic acid is not harmful to Daphnia Magma according to CLP Reg. 1272/2008/EC.

Executive summary:

The 48hr-acute toxicity of phosphinic acid 50% to Daphnia magna was studied under static conditions.  Daphni were exposed to negative control (Reconstituted water) and phosphinic acid at (nominal) concentration of 100mg/L in the definitive study and 0.10, 1.0, 10, 100mg/L in the range-finding study for 24 and 48 hr.  No immobilization was observed at 48hr. 

The 48– hour EC₅₀was > 100 mg/L. 

The 48– hr NOEC based on immobilization was >= 100 mg/L.

Based on the results of this study, Phosphinic acid would  be classified as not harmful to Daphnia Magma in accordance with CLP Reg. 1272/2008/EC. 

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009-09-21 till 2009-09-30

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

OECD guideline study in compliance to GLP standards. I

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling method: duplicate samples were taken from each treatment before the test start (0h) and at the end of the test (48h). The contents of the respective replicates for 48h samples, were combined prior to sampling.
- Sample storage conditions before analysis: deep-frozen (approximately -20 °C) immediately after sampling and protected from light

No more data available

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: freshly prepared just before introduction of the daphnids (= start of the exposure) by completely dissolving 100.5 mg of the test item in 1000 mL of test water using ultrasonic treatment for 15 minutes and stirring for 15 minutes at room temperature.
- Evidence of undissolved material: none
No more data available

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Strain: "Clone 5" (as defined by the supplier)
- Source: original source is University of Sheffield / UK which supplied the clone in 1992. Since then the clone has been bred at Harlan Laboratories.
- Age at study initiation: 6-24h old
- Method of breeding: in reconstituted water of the quality identical to the water quality used in the tests (in respect to pH, main ions, and total hardness) and under temperature and light conditions identical to those of the tests
- Feeding during test: no

ACCLIMATION
- Acclimation conditions: same as test
- Type and amount of food: algal suspension of the green algae Scenedesmus subspicatus CHODAT, Strain No. 86.81 SAG, supplied by the Collection of Algal Cultures (SAG, Institute for Plan Physiology, University of Göttingen, 37073 Göttingen / Germany) and cultivated at Harlan Laboratories under standardized conditions or a mixture of this algal suspension and a commercial fish diet (Tetra Min® Hauptfutter, supplied by TETRA-Werke, 49304 Melle / Germany).
- Feeding frequency: three times a week

No more data available

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

2.5 mmol/L (or 250 mg/L as CaCO3)

Test temperature:

21 °C

pH:

7.7 - 7.9

Dissolved oxygen:

8.2 - 8.3

Nominal and measured concentrations:

Nominal concentration: 100 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type: open (but covered with glass plates to reduce the loss of water by evaporation and to avoid the entry of dust into the solutions)
- Material: 100 mL glass beakers filled with 50 mL
- Aeration: aerated prior to the start of the study until oxygen saturation was reached. During the test period the test water was not aerated
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: volume of test solution for each daphnia was 10 mL

TEST MEDIUM / WATER PARAMETERS
- Preparation of dilution water: Reconstituted test water according to ISO 6341
- Ca/Mg ratio: 4/1
- Na/K ratio: 10/1

OTHER TEST CONDITIONS
- Photoperiod: approximately between 520 and 680 Lux
- Light intensity: 16-hour light to 8-hour dark cycle with a 30-minute transition period

EFFECT PARAMETERS MEASURED: after 24 and 48 hours of exposure daphnids were observed for immobility.

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: Based on the results of the range-finding test, which reported 0% of immobility for all treatments, it was decided to perform a limit test with 100 mg/L as the test substance is soluble at this concentration in the test medium.

No more data available.

Reference substance (positive control):

yes

Remarks:

potassium dichromate tested twice a year. Latest control: February 2009 [EC50 (48h): 0.71 mg/L, study C36915] indicated that the sensitivity of the test organisms was within the internal historical range [EC50 (48h) from 1996 to 2009: 0.53-1.1 mg/L]

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- In the control and at the test concentration of 100 mg/L, no immobilized test organisms were observed during the test period of 48 hours.
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: None

No more data available

Reported statistics and error estimates:

No statistics nor error estimates could be calculated since no toxic effect could be observed.

Validity criteria fulfilled:

yes

Conclusions:

The data from the acute toxicity of sodium phosphinate to Daphnia have been used to determine the acute toxicity of phosphinic acid to Daphnia as the latter is commercially prepared as the result of pH adjustment of the sodium phosphinate salt.
In the test conditions no toxic effect was observed in the limit test. Hence 48h-EC0 is equal to or greater than 100 mg/L and the 48h-EC50 is greater than 100 mg/L. Thus, sodium phosphinate and phosphinic acid can be considered non-hazardous to Daphnids according to the CLP regulation (EC) N° 1272/2008.

Executive summary:

The data from the acute toxicity of sodium phosphinate to Daphnia have been used to determine the acute toxicity of phosphinic acid to Daphnia as the latter is commercially prepared as the result of pH adjustment of the sodium phosphinate salt.

The study tested the acute toxicity of sodium phosphinate (monohydrate; CAS n° 10039-56-2) to Daphnia magna in a 48h immobilization test according to the OECD guideline 202 (Daphnia sp., Acute Immobilisation Test) and to the EU Method C.2 (Acute Toxicity for Daphnia). A range finding study was performed and based on these results a static limit test was performed with nominal concentration 100 mg/L.

A total of 20 daphnids (i.e. 5 animals, 4 replicates) were exposed to the test substance and as negative control an equal amount of daphnids were tested in parallel. Total exposure duration was 48h and at the start and end of the testing period different parameters were measured (pH, dissolved oxygen, temperature). Samples were taken to confirm the concentration of the test substance in the test medium. After 24h and 48h immobility was checked.

Under these test conditions the test substance concentration was stable during the testing period and no toxic effect could be observed in this study. Hence, the EC0 48h is equal to or greater than 100 mg/L and the EC50 is greater than 100 mg/L. The NOEC value after 48h is equal to or greater than 100 mg/L.

In conclusion, sodium phosphinate show no acute toxic effects on Daphnia magna up to the nominal concentration of 100 mg/L. Thus the test substance and phosphinic acid can be considered non-hazardous to Daphnids according to the CLP regulation (EC) N° 1272/2008.

The study was performed according to OECD guideline in compliance to GLP standards (certificate included) and all validity criteria were fulfilled.

Description of key information

One key study was available on sodium phosphinate by read across. The test was performed according to standard guideline with GLP compliance and gave a 48h EC50 greater than 100 mg/L and a NOEC value after 48h equal to or greater than 100 mg/L.
Therefore, phosphinic acid can be considered non-hazardous to the invertebrate organisms according to the CLP regulation (EC) n° 1272/2008.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

One key study on sodium phosphinate and one supportive study on phosphinic acid are available.

Phosphinic acid is commercially prepared as the result of pH adjustment of the sodium phosphinate salt. The main assumption is that in aqueous solution the acid and the salt will be fully dissociated and the sodium cation is not significant in respect to short-term effects on aquatic invertebrates which are expected to be related to the phosphinate anion. Hence the phosphinic acid properties can be directly read across from its salt, the sodium phosphinate.

The acute toxicity on sodium phosphinate was tested on Daphnia magna in a 48h immobilization test according to the OECD guideline 202 (Daphnia sp., Acute Immobilisation Test) and to the EU Method C.2 (Acute Toxicity for Daphnia). A range finding study was performed and based on these results a static limit test was performed with a nominal concentration of 100 mg/L.

Samples were taken to confirm the concentration of the test substance in the test medium. After 24h and 48h immobility was checked.

Under these test conditions the test substance concentration was stable during the testing period and no toxic effect could be observed in this study.

Hence, the EC50 is greater than 100 mg/L. The NOEC value after 48h is equal to or greater than 100 mg/L.

Key study results are supported by a klimish 2 study performed on Phosphinic acid. Authors tested the 48h acute toxicity of phosphinic acid 50% to Daphnia magna under static conditions.  Daphnids were exposed to negative control and phosphinic acid at (nominal) concentration of 100mg/L in the definitive study. Immobilization was observed at 48hr. The 48h EC₅₀was > 100 mg/L and the 48h NOEC was >= 100 mg/L. The two validity criteria are fulfilled and the results confirm the result observed in the key study.

 

Therefore, the test substance phosphinic acid can be considered non-hazardous to the invertebrates organisms according to the CLP regulation (EC) n° 1272/2008.