Calcium hydrogen phosphonate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22 October 2012 - 14 December 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study has been performed according to OECD and/or EC guidelines and according to GLP principles

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

Qualifier:

according to guideline

Guideline:

ISO 7346-1 (Determination of the Acute Lethal Toxicity of Substances to a Freshwater Fish [Brachydanio rerio Hamilton-Buchanan (Teleostei, Cyprinidae)] - Part 1: Static Method)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

During the limit test singular samples for possible analysis were taken from both test groups according to the schedule below.
Frequency:at t=0 h and t=96 h
Volume :10 ml
Storage :Samples were stored in a freezer until shipment to TNO Triskelion for analysis.
Additionally, singular reserve samples of 10 ml were taken from both test solutions for possible analysis. If not already used, these samples were stored in a freezer for a maximum of three months after delivery of the draft report, pending on the decision of the sponsor for additional analysis.

Vehicle:

no

Details on test solutions:

The batch of Phosphonic acid (Phosphorous acid) tested was a white crystalline solid with a purity of 99.1% (w/w) and completely soluble in test medium at the concentrations tested.

Preparation of test solutions started with the highest test concentration of 100 mg/l. No special treatment other than careful mixing was needed to completely dissolve the test substance in test medium. The pH of this solution was adjusted from 3.3 to 6.0 using Sodium Hydroxide (1M, Merck, Darmstadt, Germany). The lower test concentrations for the range-finding test were prepared by subsequent dilution of the highest test concentration in test medium. The final test solutions were all clear and colourless.

Test organisms (species):

Cyprinus carpio

Details on test organisms:

Species: Carp (Cyprinus carpio, Teleostei, Cyprinidae) Linnaeus, 1758
Source: Zodiac, proefacc, "De Haar Vissen", Wageningen University and Research Centre, The Netherlands.
Mean length : Range-finding test: 3.8 ± 0.2 cm, Limit test: 2.3 ± 0.1 cm
Mean weight: Range-finding test: 1.48 ± 0.24 g, Limit test: 0.25 ± 0.05 g
Characteristics: F1 from a single parent-pair bred in UV-treated water.
Reason for selection: This system has been selected as an internationally accepted species.
Feeding: Daily with pelleted fish food (Cyprico Crumble Excellent (300-500 um), Coppens International bv, Helmond, The Netherlands)
Quarantine/Acclimatisation: At least 12 days after delivery
Validity of batch: In the batch of fish used for the test, mortality during the seven days prior to the start of the test was less than 5%.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

hardness of 180 mg CaCO3 per litre.

Test temperature:

between 21.2 and 21.5ºC

pH:

Between 6.1 and 8.0

Dissolved oxygen:

Between 5.8 and 9.1 mg O2 / L

Nominal and measured concentrations:

Nominal concentrations: 0 mg/l and 100 mg/l.
Measured concentrations: Analysis of the samples taken from nominally 100 mg/l at the start and the end of the limit test showed measured concentrations of 100 and 104 mg/l, respectively. Results could therefore be related to the nominal test concentration.

Details on test conditions:

Test duration: 96 hours
Test type: Static
Test vessels: 6.5 litres, all-glass, containing 5 litres of test solution
Test medium:Adjusted ISO medium, formulated using RO-water (tap-water purified by reverse osmosis; GEON Waterbehandeling, Berkel-Enschot, The Netherlands) with the following composition:
CaCl2.2H2O: 211.5 mg/l
MgSO4.7H2O : 88.8 mg/l
NaHCO3: 46.7 mg/l
KCl : 4.2 mg/l
Number of fish : 7 per concentration
Loading: 0.35 g fish/litre, i.e. 7 fish per 5 litres of test medium
Illumination: 16 hours photoperiod daily
Aeration: The test media were not aerated during the test.
Feeding: No feeding from 24 hours prior to the test and during the total test period
Introduction of fish: Within 12 minutes after preparation of the test media from a holding tank with comparable water quality parameters and pH and temperature differences between test and holding tank media of less than 0.5 unit and 0.5°C.
Euthanasia: At the end of the test the surviving fish were rapidly killed by exposing them to ca. 1.2% ethylene glycol monophenylether in water.
Intervals of water quality measurement: Dissolved oxygen content pH and temperature, Daily in all vessels with surviving fish, beginning at the start of the test (day 0).
EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :dayly observation of mortality and other effects. Expressed as LC50 (t= 96 H)

Reference substance (positive control):

yes

Remarks:

pentachlorophenol (PCP)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

Behavioral abnormalities:
- Mortality of control: No mortality in control
- Abnormal responses: no abnormalities were observed
- Effect concentrations exceeding solubility of substance in test medium: no

Results with reference substance (positive control):

Under the conditions of the present test with carp exposed to PCP, the 96h-LC50 was 0.25 mg/l based on nominal concentrations, with a 95% confidence interval between 0.20 and 0.41 mg/l. This effect was already reached within 24 hours of exposure.

Reported statistics and error estimates:

No LC50 could be calculated because the test substance proved to be non-toxic (LC50 > maximum concentration tested).

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present test Phosphonic acid (Phosphorous acid) induced no visible or lethal effects in carp at or below 100 mg/l.
The 96h-LC50 exceeded an analytically confirmed exposure concentration of 100 mg/l.

Executive summary:

A 96-h acute toxicity study was perdormed on carp (Cyprinus carpio) Carp with Phosphonic acid (Phosphorous acid) according to OECD TG 203 (1992) and under the conditions for GLP. In addition, the procedures were designed to meet the test methods of the Commission Regulation (EC) No 440/2008, Part C.1, 2008 and the ISO International Standard 7346-1: Static method, 1996. The test was performed as a limit test. Seven Carp per test group were exposed for 96 hours to an untreated control and to a nominal Phosphonic acid (Phosphorous acid) concentration of 100 mg/l. Analysis of the samples taken from nominally 100 mg/l at the start and the end of the limit test showed measured concentrations of 100 and 104 mg/l, respectively. Results could therefore be related to the nominal test concentration.

The study met the acceptability criteria prescribed by the protocol and was considered valid. Phosphonic acid (Phosphorous acid) induced no visible or lethal effects in carp at or below 100 mg/l. The 96h-LC50 exceeded the exposure concentration of 100 mg/l.

Description of key information

In a key study phosphonic acid was tested on the carp Cyprinus carpio according to OECD Guideline 203 and under GLP. The test was performed as a limit test with 100 mg/l. The test concentration was verified by analytical measurements. After 96 hours, no mortality was observed. A supporting study on potassium phosphonate with Danio rerio came to the same conclusion. Phosphonic acid, calcium salt (1:1) is therefore considered slightly harmful to fish by read-across.