Dizinc pyrophosphate

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Concentrations 6.25, 12.5, 25.0, 50.0 and 100 mg/L were smapled at test start and test termination

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test item solutions were prepared in dilution water. Initially, a stock solution was prepared by weighing in an adequate amount of the test item, transferring it to dilution water and stirring it overnight. The stock solution was filtered by bottle top filter (polyethersulfone; PES) in order to remove any insoluble material before application in the test. The stock solution was adequately diluted in dilution water in order to reach the final test concentrations.

Test organisms (species):

Danio rerio (previous name: Brachydanio rerio)

Details on test organisms:

TEST ORGANISM
- Common name: Zebrafish
- Source: bred at testing facility
- Length at study initiation (length definition, mean, range and SD): 1.7 cm (SD 0.1)
- Weight at study initiation (mean and range, SD): 0.051 g (SD 0.006)

ACCLIMATION
- Acclimation period: 12 d
- Acclimation conditions (same as test or not): same
- Type and amount of food during acclimation: live brine shrimp (Artemia salina) nauplii and ground flake food TetraMin® (Tetra Werke, Melle, Germany), ad libitum
- Feeding frequency during acclimation: once daily
- Health during acclimation (any mortality observed): <5%

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

1.2 mmol/L

Test temperature:

22.8 - 23.1 °C

pH:

8.2 - 8.4

Dissolved oxygen:

94% - 102%

Conductivity:

271 µS/cm

Nominal and measured concentrations:

Nominal test substance concentrations: 6.25, 12.5, 25.0, 50.0 and 100 mg/L
Geometric meansof the test item concentration: 0.324, 0.619, 1.169, 2.061 and 4.508 mg TI/L (corresponding to 5.2, 5.0, 4.7, 4.1 and 4.5 % of nominal loading).
Geometric mean Zn concentrations: 0.140, 0.268, 0.505, 0.891 and 1.948 mg Zn/L (corresponding to 5.2, 5.0, 4.7, 4.1 and 4.5% of nominal loading).

Details on test conditions:

TEST SYSTEM
- Test vessel: glass beakers (2.5 L)
- Type (delete if not applicable): open / closed
- Fill volume: 2.0 L
- Aeration: slightly aerated via glass capillaries
- No. of organisms per vessel: 7
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.179 g/L

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: purified tap water accroding to OECD 203
- Chlorine: < 0.02 mg/L
- Alkalinity: 1.8 mmol/L
- Ca/mg ratio: 0.5
- Culture medium different from test medium: no
- Intervals of water quality measurement:

OTHER TEST CONDITIONS
- Photoperiod: light/dark cycle was adjusted to 12/12 hours

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and symptoms of intoxication after 3, 24, 48, 72 and 96 hours

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 2
- Range finding study
- Test concentrations: nominal test concentrations of 0.2, 2.0 and 20.0 mg test item/L
- Results used to determine the conditions for the definitive study: No fish was found dead during the course of the test. However, it was decided to adjust the procedure of test item preparation in order to ensure a maximum loading of the test item.

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 4.508 other: mg TI/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 1.948 other: mg Zn/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

other: Zn

Basis for effect:

mortality (fish)

Details on results:

During the test neither signs of any disease nor stress like discoloration or abnormal behavior were observed. Biological effects concerning e.g. swimming behavior, position, orientation in the water phase could not be detected. .
No mortality was observed during the test period. Thus, it was not possible to calculate a LC50 value for the test item.

Validity criteria fulfilled:

yes

Description of key information

Not acutely toxic to fish.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

4.5 mg/L

Additional information

The acute toxicity of dizinc pyrophosphate to Danio rerio was determined in a study following OECD 203 (GLP). Seven fish were exposed to nominal substance concentrations of 6.25, 12.5, 25.0, 50.0 and 100 mg/L in a static test system. A stock solution of 100 mg/L (nominal) was prepared, which was stirred at room temperature overnight followed by filtration i.e. removal of undissolved test item. This solution was used to prepare the nominal concentrations. The concentrations were analytically verified by ICP-MS. The geometric mean measured concentrations were 0.324, 0.619, 1.169, 2.061 and 4.508 mg /L corresponding to 0.140, 0.268, 0.505, 0.891 and 1.948 mg Zn/L. The test was terminated after 96 hours of exposure. Mortality or symptoms of intoxication like abnormal swimming behaviour were not observed. A definite LC50 value could not be calculated. The reported LC50 (96 h) is > 4.508 mg test substance/L (geom. mean measured), based on the Zn concentration a LC50(96 h) >1.948 mg Zn/L.

Based on the results of the available study dizinc pyrophosphate is considered not acutely toxic to fish.