Sodium Salts of (1-Hydroxyethylidene)bisphosphonic acid (1-2:1)

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:

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: US EPA 1975, Methods for acute toxicity tests with fish, macroinvertebrates and amphibians.

Deviations:

no

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: an appropriate amount of CP65184 was added directly to the sea water in each test vessel to obtain the desired concentrations.

- Controls: sea water only

Test organisms (species):

Palaemonetes pugio

Details on test organisms:

TEST ORGANISM

- Common name: grass shrimp

- Source: Big Lagoon, near Bionomics Research Laboratory (BMRL)

- Length at study initiation (length definition and range): rostrum-telson length 15-20 mm a time of collection from stock

- Method of breeding: not reported

- Feeding during test: animals were not fed during test


ACCLIMATION

- Acclimation period: 7 days

- Acclimation conditions (same as test or not): not reported, animals are said to be acclimatised to laboratory conditions.

- Health during acclimation (any mortality observed): <1% mortality

Test type:

static

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

Water temperature was maintained at 21 degrees C.

pH:

Initial pH ranged from 5.4 in the highest concentration to 6.9 in the lowest concentration, controls were 8.3. Final pH ranged from 5.5 in the highest concentration to 6.9 in the lowest concentration, controls were 8.1.

Salinity:

25 %o

Nominal and measured concentrations:

Nominal concentrations: 1000, 10000, 18000, 32000, 56000 ul/L (ppm)

Details on test conditions:

TEST SYSTEM

- Test vessel: jars

- Type (delete if not applicable): open

- Material, size, fill volume: 19 L uncovered glass jars with 15L test medium.

- Aeration: no

- No. of organisms per vessel: 10

- No. of vessels per concentration (replicates): 1

- No. of vessels per control (replicates): 1


TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: natural filtered (5 um filters) sea water

- Culture medium different from test medium: no

- Intervals of water quality measurement: pH was measured at the beginning and end of the test; salinity, temperature and DO intervals of measurements are not reported.


OTHER TEST CONDITIONS

- Adjustment of pH: no

- Photoperiod: not reported

- Light intensity: not reported


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality was observed at 0, 24, 48 and 96 h.


TEST CONCENTRATIONS

- Spacing factor for test concentrations: 2

- Range finding study: not reported

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

3 925 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

1 770 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

- Mortality of control: 0%

Reported statistics and error estimates:

LC50 values were calculated by linear regression.

Table 1. Summary of findings.

 

Nominal concentrations (ul/L/ppm)	Mortalities (%)
	24 h	48 h	96 h
Control	0	0	0
1,000	0	0	0
10,000	0	0	0
18,000	30	40	60
32,000	0	50	100
56,000	100	100	100

 

Result expressed as nominal concentration. Properties of the test substance and evidence from other studies (where concentrations were measured) indicate that nominal and measured concentrations are likely to be in good agreement.

LC50 corrected for density (1.1) and % active acid (9.42%),

uncorrected LC50 values: 24 h - >32,000 <56,000; 48 h - 23,202; 96 h - 17,044 ppm

corrected LC50 values: 24 h - >3316 <5803; 48 h - 2402; 96 h - 1766 mg/L active acid

Validity criteria fulfilled:

no

Remarks:

the pH of the test medium lowered with increasing concentration

Conclusions:

A reliable 96 h LC50 value of 1770 mg/L (active acid) has been determined for the effects of the test substance on mortality of the marine shrimp P. pugios.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

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:

equivalent or similar to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

not applicable

Qualifier:

according to guideline

Guideline:

other: MIC Environmental Assessment Method for Conducting Acute Toxicity Tests with Daphnia Magna (Grueber and Adams, 1980)

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: US EPA 1975, Methods for Acute Toxicity Tests with Fish, Macroinvertebrates and Amphibians

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: each concentration was made by direct addition into 1L of dilution water and shaken vigorously for 1 minute. The solution was then divided into 3 200 ml aliquots. The remaining 400 ml were used for 0-hour DO, pH, alkalinity and hardness determinations.

- Controls: dilution water only

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM

- Source: MIC Aquatic Laboratory

- Age at study initiation (mean and range, SD): <24 h old

- Method of breeding: not reported

- Feeding during test: no


ACCLIMATION

- Acclimation period: none, cultured at the lab where the tests were conducted

- Acclimation conditions (same as test or not): similar

- Type and amount of food: mixture of Purina trout chow and alfalfa

- Feeding frequency: daily

- Health during acclimation (any mortality observed): not reported

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

range: 250 to 300 mg/L; dilution water: 297 mg/L CaCO3

Test temperature:

Maintained at room temperature, average temperature was 21.2 degC

pH:

pH in controls was within guideline values. The pH of the test media ranged between 2.0 in the highest test concentration to 8.2 in the lowest.

Dissolved oxygen:

DO in controls was within guideline values.

Nominal and measured concentrations:

Nominal concentrations: control, 100, 200, 400, 800 and 1600 mg active acid/L

Details on test conditions:

TEST SYSTEM

- Test vessel: beaker

- Type (delete if not applicable): open

- Material, size, headspace, fill volume: 250 ml beakers with 200 ml test solution

- Aeration: no

- No. of organisms per vessel: 10

- No. of vessels per concentration (replicates): 3

- No. of vessels per control (replicates): 3


TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: well water from St. Peters, Missouri

- Alkalinity: 303 mg/L CaCO3

- Culture medium different from test medium: not reported

- Intervals of water quality measurement: oxygen, pH, alkalinity, hardness and temperature were measured at the beginning and end of test in the high, middle, low and control concentrations.


OTHER TEST CONDITIONS

- Adjustment of pH: no

- Photoperiod: not reported


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobility at 24 and 48 h


TEST CONCENTRATIONS

- Spacing factor for test concentrations: 2


- Range finding study

- Test concentrations: not reported

- Results used to determine the conditions for the definitive study: 409 mg active acid/L

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

400 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: immobility

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

527 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: immobility

Remarks on result:

other: (466-610)

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

871 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

other: immobility

Details on results:

- Mortality of control: 0%

Reported statistics and error estimates:

The EC50 values and their 95% confidence intervals were calculated using a computer programme developed by Stephen et al of the US EPA.

Table 1. Percentage immobilisation at 24 and 48 h.

 

Concentration (mg active acid/L)	Immobilisation – average of 3 replicates (%)
	24 h	48 h
Control	0	0
100	0	0
200	0	3.3
400	0	3.3
800	40	100
1600	100	100

 

Results are expressed as nominal concentration. Properties of the test substance and evidence from other studies (where concentrations were measured) indicate that nominal and measured concentrations are likely to be in good agreement.

 

Low pH for higher concentrations (resulting from acidic nature of test material) could be responsible for much of the observed toxicity. However the results still indicate a low degree of short-term toxicity.

Validity criteria fulfilled:

yes

Remarks:

in the controls, however the pH in the highest concentrations was lower than the validity criteria

Conclusions:

A reliable 48 h EC50 value of 527 mg active acid/L has been determined for the effects of HEDP on the immobility of Daphnia magna.

Description of key information

(48 h) EC₅₀ 527 mg/L D. magna (r-a) as HEDP-H (Monsanto, 1981)

(96 h) LC₅₀ 1770 mg/L P. pugio (r-a) as HEDP-H (EG&G, 1976)

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

527 mg/L

Marine water invertebrates

Marine water invertebrates

Effect concentration:

1 770 mg/L

Additional information

The results have been read-across to HEDP sodium and potassium salts in accordance with the rationale outlined in Annex 1 of the CSR. The resulting EC₅₀ once read across, taking into account ionisation state and MW, will be higher for the phosphonic sodium and potassium salts than for the acid.

The results of tests conducted on HEDP and its salts are directly comparable, because the ionisation state will depend only on the pH of the test medium. The counterion is not considered to contribute to effects in fish. At environmentally-relevant pH values, HEDP will be ionised typically three times, and will form stable complexes with metal ions.

       

Data are available assessing the short-term toxicity effects of HEDP sodium salts to invertebrates, however the study with the lowest reliable results in terms of HEDP acid have been selected as key, even if conducted on HEDP-H.

    

Freshwater

A reliable 48 h EC₅₀ value of 527 mg active acid/L has been determined for the effects of HEDP-H (CAS 2809-21-4) on the immobility of Daphnia magna (Monsanto, 1981). This is the lowest reliable value available for this endpoint and has been selected as key.

The pH in the test medium was below acceptable levels in the exposure treatments (the pH of the test media ranged between 2.0 in the highest test concentration to 8.2 in the lowest). However, the pH was within acceptable ranges in the controls and this study still suggests a very low level of HEDP toxicity towards D. magna.

Other studies show EC₅₀ values between 750 mg/L (estimated) and 3.3 g/L. 

 

Marine

A reliable 96 h LC₅₀ value of 1770 mg/L (active acid) has been determined for the effects of HEDP-H on the mortality of the marine shrimp Paleomontes pugios (EG&G, 1976). This is the lowest reliable value available for this endpoint and has been selected as key.

An estuarine study is available indicating an LC₅₀ value of >=960mg/L with Unio tumidus (Henkel, 1979).