Reaction mass of [[(2-hydroxyethyl)imino]bis(methylene)]bisphosphonic acid and Phosphonic acid, P-[(tetrahydro-2-hydroxy-2-oxido-4H-1,4,2-oxazaphosphorin-4-yl)methyl]-

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

between 1999-01-20 and 1999-01-22

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to an appropriate national standard method. It was compliant with GLP however no analytical monitoring was carried out.

Qualifier:

according to guideline

Guideline:

other: ISO TC147SC5/WG2 "Water quality, determination of acute lethal toxicity to marine copepods (Copepoda crustacea)".

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION

- Method: 400 mg of test material (= 200 mg active ingredient) was dissolved in synthetic sea water and the volume adjusted to 2 L to give the 100 mg active ingredient (ai)/L test concentration. Aliquots of this concentration were separately dispersed in synthetic sea water and the volume adjusted to 1 L to give the remaining test concentrations.

Test organisms (species):

other aquatic arthropod: Acartia tonsa

Details on test organisms:

TEST ORGANISM

- Source: Guernsey Sea Farms Ltd, Parc Lane, Vale, Guernsey, UK

- Age at study initiation (mean and range, SD): stage 5, adults

- Method of breeding: not reported

- Feeding during test: none


ACCLIMATION

- Acclimation period: not reported

- Acclimation conditions (same as test or not): same temperature and salinity as study

- Type and amount of food: mixed culture of marine algae

- Feeding frequency: not reported

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

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test temperature:

21⁰C

pH:

range: 6.4 to 8

Dissolved oxygen:

5.9 to 6.3 mg O2/L

Nominal and measured concentrations:

Nominal concentrations: 1.8, 3.2, 5.6, 10, 18, 32, 56 and 100 mg active ingredient (ai)/L

Details on test conditions:

TEST SYSTEM

- Test vessel: jars

- Material, size, fill volume: 50 ml glass jars filled with 25 ml solution

- Aeration: none

- No. of organisms per vessel: 5

- No. of vessels per concentration (replicates): 4

- No. of vessels per control (replicates): 4


TEST MEDIUM / WATER PARAMETERS

- Source/preparation of dilution water: the test water was prepared using a commercially available formulation, manufactured by Dr Biener GmbH, Aquarientechnik, 36367 Wartenberg, Germany and supplied by CJ Skilton, Chelmsford, UK.

- Culture medium different from test medium: yes

- Intervals of water quality measurement: temperature was recorded throughout


OTHER TEST CONDITIONS

- Adjustment of pH: not reported

- Photoperiod: 16 h light: 8 h darkness with 20 mi dusk and dawn transition periods

- Light intensity: not reported


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : the number of immobile animals were recorded after 24 and 48 hours.


TEST CONCENTRATIONS

- Spacing factor for test concentrations: ca. 1.8

- Range finding study

- Test concentrations: 0.01 to 100 mg/l

- Results used to determine the conditions for the definitive study: no mortalities were observed at test concentrations up to 10 mg a.i./L. However, mortalities were observed at 100 mg a.i./L.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

64 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

acid

Basis for effect:

mobility

Remarks on result:

other: 95% CL 55-75 mg a.i./L

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

82 mg/L

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Remarks:

acid

Basis for effect:

mobility

Remarks on result:

other: 95 % CL 64-104

Results with reference substance (positive control):

- Results with reference substance valid? yes

- EC50/LC50: 6.2 mg/l

Reported statistics and error estimates:

The LC50 was determined by the moving average method of Thompson (1947)

Table 1. Summary of findings.

Nominal concentrations (mg a.i./L)	Mortalities (%)
	24 h	48 h
Control	0	0
1.0	0	0
1.8	0	0
3.2	0	0
5.6	0	0
10	0	0
18	0	0
32	0	0
56	20	35
100	70	90

Validity criteria fulfilled:

yes

Conclusions:

A 48h EC50 value of 64 mg active acid/L has been reported for the effects of the test substance on the mobility of the freshwater copepod Acartia tonsa based on nominal concentrations.

Description of key information

A reliable test result of 48 hour EC₅₀ 64 mg active acid/L, A. tonsa, based on nominal concentrations of active acid is available for HEBMP-H.

Key value for chemical safety assessment

Marine water invertebrates

Marine water invertebrates

Dose descriptor:

EC50

Effect concentration:

64 mg/L

Additional information

A 48 hour EC₅₀ value of 64 mg active acid/L has been reported for the effects of HEBMP acid on the mobility of the marine copepod Acartia tonsa based on nominal concentrations. This result is interpreted as 64 mg/l as active acid. Whilst the proportion of cyclic and linear constituents was not measured for the tested sample, it is conservatively interpreted that the cyclic constituent could have been present at ca. 50% w/w.