Carbazamidine sulphate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Test guideline 3

Qualifier:

according to guideline

Guideline:

ISO 6341 (Water quality - Determination of the Inhibition of the Mobility of Daphnia magna Straus (Cladocera, Crustacea))

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Guanidinium phosphate (1:1)

EC Number:

226-551-9

EC Name:

Guanidinium phosphate (1:1)

Cas Number:

5423-22-3

Molecular formula:

CH5N3.H3O4P

IUPAC Name:

Guanidium phosphate (1:1)

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Blank control and 100 mg/L
- Sampling
Frequency: at t=0 h and t=48 h
Volume: 1 mL
- Sample storage conditions before analysis: Samples were transported on dry ice to TNO Triskelion (P.O. Box 844, 3700 AV, Zeist, The Netherlands) and were stored in a freezer until analysis.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: Preparation of test solutions started with a nominal concentration of 100 mg/L applying a short period of vigorous shaking to accelerate the dissolving of the test substance in the test medium.
- Controls: Blank control containing test medium without test substance or other additives
- Evidence of undissolved material (e.g. precipitate, surface film, etc): The final test solution was clear and colourless.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Source: In-house laboratory culture with a known history
- Age at study initiation: <24 h
- Feeding during test: None

BREEDING:
- Method: At least third generation obtained by acyclical parthenogenesis under specified breeding conditions. Each batch started with newborn daphnids (i.e. less than three days old) and the maximum age of the cultures was 4 weeks
- Medium: M7 prepared according to Elendt, B.-P., 1990: Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus. Protoplasma 154, 25-33.
- Conditions (same as test or not): yes
- Type of food: suspension of fresh water algae
- Feeding frequency: Daily
- Health during acclimation (any mortality observed): Daphnids originated from a healthy stock, 2nd to 5th brood, showing no signs of stress such as mortality >20%, presence of males, ephippia or discoloured animals and there was no delay in the production of the first brood.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

180 mg/L expressed as CaCO3

Test temperature:

Start: 20.3 to 20.5 °C
During test period: 19.4 - 19.9 °C

pH:

Start: 6.8 - 7.8
End: 7.4 - 8.2

Dissolved oxygen:

Start: 9.2 - 9.3 mg/L
End: 8.9 mg/L

Nominal and measured concentrations:

- Nominal: blank control, 0.1, 1, 10 and 100 mg/L
- Measured
t=0h: <0.08 mg/L* (blank control) and 97 mg/L (100 mg/L).
t=48h: <0.08 mg/L* (blank control) and 107 mg/L (100 mg/L)
*) LOD was 0.08 mg/L (lowest calibration point).

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL, all glass, containing 80 mL of test solution
- Aeration: None
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4 for the highest test concentration (100 mg/L) and 2 for each lower concentration (0.1 - 10 mg/L)
- No. of vessels per control (replicates): 4
- Loading: 5 daphnids per 80 mL of test solution

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: tap water purified by Reverse Osmosis
- Culture medium different from test medium: Yes
- Intervals of water quality measurement:
pH was measured at the beginning of the test for the control and all test concentrations. At the end of the test for the control and the highest test concentration.
Dissolved oxygen was measured at the beginning and at the end of the test for both the control and the highest test concentration.
Temperature was measured continuously in a temperature control vessel.

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: 16 h light : 8 h dark

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): Immobility (including mortality) at 24 and 48 h.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: x10

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 33 mg/L

Nominal / measured:

nominal

Conc. based on:

other: guanidine content (32.7% w/w)

Basis for effect:

mobility

Details on results:

- Measured concentrations: Analysis of the samples taken from the 100 mg/L concentration showed that the actual concentration was in agreement with nominal and remained stable during the test period (97-107%). Given this result the EC50-value was based on the nominal test concentration.

- Biological results: A single daphnid was found immobilized at the highest test concentration (100 mg/L). For the lower test concentrations and the blank control no immobilized daphnids were observed.

- Acceptability of the test:
1. In the control, no daphnids became immobilised.
2. The oxygen concentration at the end of the test was ≥3 mg/L in control and test vessels.

Results with reference substance (positive control):

- Potassium dichromate (K2Cr2O7): The 48h-EC50 was 0.53 mg/L (95% confidence interval between 0.49 and 0.62 mg/L)

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The 48h-EC50 for Daphnia magna exposed to Guanidine phosphate (1:1) was >100 mg/L

Executive summary:

In a 48-h acute toxicity study conducted according to OECD guideline 202, water fleas (Daphnia magna) were exposed to Guanidine phosphate (1:1) under static conditions at the following nominal concentrations: 0 (blank control), 0.1, 1, 10 and 100 mg/L. The test substance induced no immobilization in daphnids at a nominal exposure concentration of 100 mg/L. The 48h-EC50 was >100 mg/L (corresponding to >33 mg guanidine/L) based on analytically confirmed nominal concentrations. The study is considered to be reliable without restrictions.