Pyridinium toluene-4-sulphonate

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

May 2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Version / remarks:

April 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Duplicate samples were taken from each treatment at the start and at the end of the test (after 48 hours). For the 48-hour stability samples, the contents of the respective replicates were combined prior to sampling.
All samples were stored frozen (at about -20 ± 5 C) immediately after sampling.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: An aqueous solution with a nominal content of 80 % was prepared prior to the test. The test substance content of this working solution was analytically verified by HPLC to be 77.9 % (water-free). The test medium with a nominal concentration of 100 mg/L was prepared by completely diluting 130.17 mg of the working solution (corresponding to 101.4 mg water-free test substance) in 1 L of test water by intensive stirring at room temperature for 30 minutes in the dark. The test medium was prepared just before the introduction of the daphnids (i.e., start of the test).
- Controls: test water

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flee
- Strain/clone: STRAUSS
- Source: in-house culture
- Feeding during test: none

ACCLIMATION
- Acclimation period: none. Breeding was performed in reconstituted water (Elendt M7 Medium), temperature and light conditions were identical to those in the test.
- Type and amount of food: green algae suspension (Desmodesmus subspicatus) or a mixture of this suspension and a commercial fish diet (TETRA MIN Hauptfutter, TETRA-Werke, 49304 Melle / Germany), three times a week
- Health during acclimation (any mortality observed): no mortality or signs of stress were observed and the brood stock was healthy.

The daphnids used for the test were 6 - 24 hours old and were not first brood progeny.

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

2.5 mM (250 mg CaCO3/L)

Test temperature:

21 - 22 °C

pH:

7.8 - 7.9

Dissolved oxygen:

≥ 8.2 mg O2/L

Nominal and measured concentrations:

nominal concentration: 101 mg/L (water-free)
measured concentration: 106 and 108 % of nominal (test start and end)
The biological results are based on the nominal concentration of the test item.

Details on test conditions:

TEST SYSTEM
- Test vessel: 100 mL glass beakers containing 50 mL test medium, covered with disposable polypropylene sheets
- Aeration: none
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: 10 mL/animal

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water (ISO 6341) according to the guidelines. Analytical grade salts were dissolved in ultrapure water.
- Ca/Mg ratio: 4:1
- Alkalinity: 0.8 mM
- Culture medium different from test medium: yes (daphnids were cultured in Elendt M7 Medium)
- Intervals of water quality measurement: water temperature, oxygen concentration and pH were measured at the start and at the end of the test in each treatment.
OTHER TEST CONDITIONS
- Adjustment of pH: yes; the pH of the test medium was adjusted from 6.4 to 7.9 with a 1 M NaOH solution)
- Photoperiod: 16-hour light to 8-hour dark cycle with a 30-minute transition period
- Lighting: between approximately 13 and 18 µE m-2 s-1

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
Daphnids were inspected for immobility and sub-lethal effects (discolouration, surface trapping, incoherent swimming pattern, etc.) after 24 and 48 hours of exposure.

RANGE-FINDING STUDY
- Results used to determine the conditions for the definitive study: no toxic effects up to and including nominal 100 mg/L.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

corrected for water-content

Basis for effect:

mobility

Key result

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks:

corrected for water-content

Basis for effect:

other:

Remarks:

mobility and sub-lethal effects

Details on results:

Behavioural abnormalities:
- Other biological observations: no adverse effects were observed
- Mortality of control: none
- Other adverse effects control: none
- Abnormal responses:

The test medium was a clear solution throughout the test period of 48 hours.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Relevant effect levels:
- 24-hour EC50: 1.0 mg/L (within the range 0.6 – 2.1 mg/L as given by the guidelines)

Reported statistics and error estimates:

The 24-hour and 48-hour EC50 of the test item could not be calculated, because none of the responses exceeded 50 %. The EC50 values, the NOEC, the LOEC and EC100 value were therefore determined directly from the raw data.

Validity criteria fulfilled:

yes

Remarks:

In the control, not more that 10 % of the daphnids have been immobilised or showed other sub-lethal effects; the dissolved oxygen concentration at the end of the test was > 3 mg/l in all vessels.

Description of key information

48-h EC50 > 100 mg/L for Daphnia magna (OECD 202, EU C.2)

Additional information

EC50/LC50 for freshwater invertebrates: > 100 mg/L