Phosphinic acid

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

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.

Please also refer to the Read across Justification document provided in Section 13

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: visible abnormalities

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: visible abnormalities

Details on results:

- Behavioural abnormalities: none
- Other biological observations: none
- Mortality of control: none
- Other adverse effects control: none
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 1995-02-06 to 1995-01-17

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 203, but there is no data regarding GLP procedures and no analytical monitoring has been performed to check the stability of the substance during the test. However other validity criteria have been fulfilled.

Reason / purpose for cross-reference:

read-across: supporting information

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

yes

Remarks:

stability of the substance not recorded

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
no more data

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow Trout
- Strain: no data
- Source: Donnington Fish Farm, Upper Swell Glouscester, U.K
- Age at study initiation: no data
- Length at study initiation : 5.0 +/- 0.2 cm
- Weight at study initiation : 1.65 +/- 0.22 g
- Method of breeding: no data
- Feeding during test: no data
- other: no medication during test

ACCLIMATION
- Acclimation period: 7 days
- Health during acclimation (any mortality observed): ~ 1% in the 7 days prior to the study start

no more data

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

Approximately 100 mg/L as CaCO3

Test temperature:

14°C

pH:

Between 7.2 and 7.5 for control
Between 6.2 and 7.5 in test sample at 100 mg/L

Dissolved oxygen:

Between 10.2 and 9.8 mg O2 /L both in control and test sample

Nominal and measured concentrations:

Nominal:
-Range-finding study: 0; 1.0; 10; 100 mg/L
-Definitive study: 0; 100mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open / closed: no data
- Material size: 20 L
- Aeration: YES
- Renewal rate of test solution : media renewed daily
- No. of organisms per vessel: 10
- No. of vessels per concentration: 2
- No. of vessels per control: 1
- Biomass loading rate: 0.83 g bodyweight/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dechlorinated tap water (by passage through an activated carbon filter)
- Intervals of water quality measurement: every 24 hours

OTHER TEST CONDITIONS
- Adjustment of pH: there were treatment related to differences in pH observed at 0 hour upon preparation. However it would appear that the declorinated tap water had a sufficient buffering capacity to eleviate the initial drop in pH after addition of the test material.
- Oxygen: There were no treatment related differences for oxygen concentration
- Photoperiod: no data
- Light intensity: no data

EFFECT PARAMETERS MEASURED: cumulative mortality, every 24 hours (with an added observation at 3 and 6 hours)

TEST CONCENTRATIONS:
- unique concentration tested : 100mg/L (limit test)

RANGE FINDING STUDY: at 0; 1.0; 10; 100 mg/L

Reference substance (positive control):

not specified

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Mortality of control: none
no more data

Reported statistics and error estimates:

no data

Sublethal observations / clinical signs:

Table 2: Cumulative Mortality data for Rainbow trout exposed for 96 hours to Albrite Hypophosphorous acid 50%

Nominal Concentration (mg/L)		Cumulative mortality (initial population :10)
		3h	6h	24h	48h	72h	96h
Control	R1	0	0	0	0	0	0
100	R1	0	0	0	0	0	0
100	R2	0	0	0	0	0	0

Validity criteria fulfilled:

no

Remarks:

partially fulfilled. See overall remarks for details

Conclusions:

In the test conditions phosphinic acid is not harmfull to rainbow trouts (Oncorhynchus mykiss) according to CLP Reg 1272/2008/EC.

Executive summary:

In an acute toxicity study according to OECD guideline 203, fishes from the species Oncorhynchus mykiss were exposed under semi-static conditions to phosphinic acid during 96h of exposure. Two series of 10 specimens have been tested at a single nominal concentration of 100 mg/L (limit test). Test was performed after a preliminary study at concentration of 1.0, 10.0 and 100.0 mg/L where no mortality among the 3 animals tested was recorded over the 96h of exposure.

The LC50 (96h) was > 100 mg/L, based on nominal concentrations.

The NOEC (96h) was >= 100 mg/L, based on nominal concentrations.

Therefore, in the test conditions, phosphinic acid is not hazardous to Oncorhynchus mykiss according to CLP Reg 1272/2008/EC.

No data on GLP procedure is recorded and three of the four validity criteria were fulfilled (no evidence that the concentration has been maintained throughout the test). But as authors followed the OECD 203 guideline and other physico-chemical parameters were maintained during the test, this study is considered as reliable with acceptable restrictions.

Reference 3

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Study period:

2009-09-07 till 2009-09-29

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

OECD guideline study in compliance to GLP standards

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.

Please also refer to the Read across Justification document provided in Section 13

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.1 (Acute Toxicity for Fish)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Sampling method: duplicate samples were taken from each treatment from the approximate middle of the aquaria without mixing the test medium
- Sampling time points: before the start of the test, after 48h and at the end of the test after 96h
- Sample storage conditions before analysis: immediately after sampling stored deep-frozen (about -20°C)

No more data available

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: 550.2 mg of the test substance was completely dissolved in 5.5 L of test water using ultrasonic treatment for 5 minutes and stirring for 15 minutes at room temperature. Test medium was freshly prepared just before introduction of the fish
- Evidence of undissolved material: none

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: zebra fish
- Source: breeding culture at Harlan Laboratories
- Length at study initiation: 2.7 +/- 0.10 cm
- Weight at study initiation: 0.13 +/- 0.01 g
- Feeding during test: no

ACCLIMATION
- Acclimation period: 1 week
- Acclimation conditions: same as test (test water and temperature)
- Type and amount of food: commercial fish diet (TETRA Min Hauptfutter, supplied by TETRA-Werke, Germany)
- Feeding frequency: feeding occurred during acclimation until one day before the start of the test
- Health during acclimation (any mortality observed): fish were healthy, no medication was applied, no fish died

No more data available

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

1.25 mmol/L (or 125 mg/L as CaCO3)

Test temperature:

21°C

pH:

7.5 - 7.8

Dissolved oxygen:

8.4 mg/L - 8.7 mg/L

Nominal and measured concentrations:

Nominal concentration: 100 mg/L
Measured concentrations: ranged from 104 to 107% of the nominal value

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material: glass test vessel with 5L of test medium
- Aeration: slightly aerated
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.18 g fish wet weight/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted test water consisting of analytical grade salts dissolved in purified water (Millipore purification system) (composition see table 1 in other information on materials and methods).
- Alkalinity: 0.4
- Ca/Mg ratio: 4/1
- Na/K ratio: 10/1
- Intervals of water quality measurement: Water temperature, pH and dissolved oxygen were measured at the start of the test and once daily during the test for each treatment

OTHER TEST CONDITIONS
- Photoperiod: 16h light/8h dark (with 30 minute transition period)
- Light intensity: within range of 100 to 480 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable):
- Mortality: After 4, 24, 48, 72 and 96h.
- Visible abnormalities: After 4, 24, 48, 72 and 96h.
Visible abnormalities for which fish were observed: strongly extended gills, apathy, distended abdomen, fish mainly at the bottom of the test vessel, exophtalmus, convulsions, fish mainly at the water surface, mucus secretion, fish lying on side or back on the bottom, strong ventilation, tumbling during swimming, changed body color.

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: nominal concentrations of 0, 1.0, 10 and 100 mg/L
- Results used to determine the conditions for the definitive study: the range finding study showed that for all treatments the fish mortality after 96h was 0%, all fish appeared normal and the test medium appeared clear and had a constant test substance concentration

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC0

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: visible abnormalities

Duration:

96 h

Dose descriptor:

LOEC

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: visible abnormalities

Details on results:

- Behavioural abnormalities: none
- Other biological observations: none
- Mortality of control: none
- Other adverse effects control: none
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none

Reported statistics and error estimates:

No statistics could be performed as no mortality was observed during the entire test period.

Validity criteria fulfilled:

yes

Conclusions:

Data from the acute toxicity of sodium phosphinate to fish was used to assess the acute toxicity of the phosphinic acid as in it is commercially prepared as the result of pH adjustment.
In the test conditions, neither visible abnormalities nor mortality was observed during a limit test of 96h. Hence the LC50, and LOEC at 96h are above 100 mg/L and NOEC for 96h is equal or above 100 mg/L. Hence, the test substance sodium phosphinate and its parent compound the phosphinic acid can be considered non hazardous to the aquatic environment according to the CLP regulation (EC) n° 1272/2008.

Executive summary:

Data from the acute toxicity of sodium phosphinate to fish was used to assess the acute toxicity of the phosphinic acid as in it is commercially prepared as the result of pH adjustment.

The authors tested the acute toxicity of sodium phosphinate (CAS number 10039-56-2) to zebra fish (Brachydanio rerio) according to the OECD guideline 203 (Fish, Acute toxicity test) and according to the EU Method C.1 (Acute toxicity for fish). They performed a static freshwater limit test during 96h. The test included 1 test vessel and 1 control vessel each containing 7 zebra fish. After 4h, 24h, 48h, 72h and 96h the fish were observed and mortality and visible abnormalities was noted. Furthermore the concentration of the test material as well as the pH, temperature and dissolved oxygen was checked regularly during the test period.

Under these testing conditions no visible abnormalities or mortality was observed. Hence the LC50, and LOEC at 96h are above 100 mg/L and NOEC for 96h is equal or above 100 mg/L. The exact values of these parameters cannot be quantified due to the absence of toxicity of the test substance at the tested concentration (limit test: 100 mg/L). Hence, the test substance sodium phosphinate and its parent compound the phosphinic acid can be considered non hazardous to the aquatic environment according to the CLP regulation (EC) n° 1272/2008.

This study was performed according to OECD guideline and in compliance with GLP standards (certificate included) and all validity criteria were fulfilled, therefore, the study can be consided reliable without restrictions.

Description of key information

One key study was available for sodium phosphinate by read across on zebra fish (Brachydanio rerio) according to OECD guideline 203 with GLP compliance. The static freshwater limit test during 96h gave a LC50, and LOEC >100 mg/L and a NOEC equal or above 100 mg/L. The key study results are supported by a study performed on phosphinic acid according to a standard guideline but with deviations and not under GLP.
Therefore, phosphinic acid can be considered non-hazardous to the fish organisms according to the CLP regulation (EC) n° 1272/2008.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

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 fish 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.

During the key study, the concentration of the test material as well as the pH, temperature and dissolved oxygen was checked regularly during the test period. Under these testing conditions no visible abnormalities or mortality was observed. Hence, LC50, and LOEC at 96h are >100 mg/L and NOEC-96h is equal or above 100 mg/L. According to the CLP regulation (EC) n° 1272/2008, the result on the acute toxicity to fish would lead to a non-classification of the test substance sodium phosphinate and phosphinate anion.

In a supportive study performed according to OECD guideline 203, fishes (Oncorhynchus mykiss) were exposed under semi-static conditions to phosphinic acid during 96h. The test was not compliant with GLP and the concentrations were not measured analytically. Two series of 10 specimens have been tested in a limit test at100 mg/L. The LC50 (96h) was > 100 mg/L and the NOEC (96h) was >=100 mg/L, based on nominal concentrations.

According to the CLP regulation (EC) n° 1272/2008, the results on the acute toxicity to fish would lead to a non-classification of the phosphinate anion and phosphinic acid.