Product of Semi-Dry Absorption method of Flue Gas Desulphurization (SDA Product)

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:

31.08. - 11.09.2009

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:

2008

Deviations:

yes

Remarks:

The study was performed without the analytical determination of the test substance concentrations. For all evaluations and results nominal concentrations of the test substance were used

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

Standard dilution water was prepared just before the test by admixing 2.5 mL of stored solutions A, B, C and D into 1000 mL of deionized water.
A. 117.6 g CaCl2.2H20 in 1 L of deionized water
B. 49.3 g MgSO4.7H2O in 1 L of deionized water
C. 25.9 g NaHCO3 in 1 L of deionized water
D. 2.3 g KCl in 1 L of deionized water

The dilution water should be of pH 7.8 +/- 0.2. The sum of Ca + Mg ions should be approx. 2.5 mmol/L.

PREPARATION OF SOLUTIONS OF THE TEST SUBSTANCE
Since the test substance is poorly soluble in dilution water at concentrations needed for the test, a stock saturated solution (nominal concentration 100 mg/L) of the test substance in dilution water was prepared for preliminary and limit test.
The stock saturated solution was prepared as follows: the suspension of 100 mg of the test substance in 1000 mL of dilution water was stirred for suitable period on a shaft stirrer and consequently filtered through 0.45 μm filter.
An experiment was performed for the determination of suitable period of stirring in procedure of saturated solution preparation. During this experiment the concentrations of metals (Al, Ca, Fe, K, Mg, Na, P and Ti) in resulted solutions were determined (see Table 1). The samples of saturated solutions were prepared in dilution water, which contents metals as Ca, Mg, Na and K. For this reason the analytical determination of the concentrations of metals was performed also in pure dilution water.

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Dapnia magna
- Strain: Straus
- Source: own laboratory breeding
- Age at study initiation (mean and range, SD): young Daphnia born in 24 hours
- Method of breeding: aperiodic parthenogenesis
- Feeding during test: without feeding

ACCLIMATION / BREEDING
- Acclimation period: The grow-up gravid females are separated into dilution water. Young daphnia born in 24 hours are segregated to the handling container from which they entered the experiment.
- Acclimation conditions: same as the test
- Type and amount of food: Daphnia were fed by a mixture of algae
- Health during acclimation (any mortality observed): no

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

Preliminary test: Content of (Ca+Mg) in dilution water: 2.58 mmol/L
Limit test: Content of (Ca+Mg) in dilution water: 2.59 mmol/L

Test temperature:

22 ± 2 °C, with a variation of ± 1 °C at each individual test

pH:

Preliminary test: pH of dilution water: 7.8
Limit test: pH of dilution water: 7.7

Dissolved oxygen:

Preliminary test: 7.8 mg/L at temperature of 20.1 °C
Limit test: 8.3 mg/L at temperature of 20.1 °C

Conductivity:

Preliminary test: 0.116 mS·m-1
Limit test: 0.107 mS·m-1

Nominal and measured concentrations:

See table No. 1 and No. 2

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): open beaker
- Material, size, headspace, fill volume: glass, 50 ml of test solution
- Aeration: without
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: one young dapnia per 5 ml of the test substance


Standard dilution water was prepared just before the test by admixing 2.5 mL of stored solutions A, B, C and D into 1000 mL of deionized water.
A. 117.6 g CaCl2•2H20 in 1 L of deionized water
B. 49.3 g MgSO4•7H2O in 1 L of deionized water
C. 25.9 g NaHCO3 in 1 L of deionized water
D. 2.3 g KCl in 1 L of deionized water
The dilution water should be of pH 7.8 +/- 0.2. The sum of Ca + Mg ions should be approx.
2.5 mmol/L

Conductivity of deionized water: 0.107 mS/m

OTHER TEST CONDITIONS
- Photoperiod: natural variation of daily light and dark
- Light intensity: natural

TEST CONCENTRATIONS
The stock saturated solution of the test substance in dilution water was prepared for limit test. The limit test was performed in range nominal concentrations from 62 mg/L to 100 mg/L. For the test was used geometric concentration series of the test substance with factor 1.1. The test solutions were prepared by dosing of appropriate volumes of stock saturated solution into volumetric flasks and replenishment up to mark with dilution water. Control test was carried out concurrently with dilution water only. The test was performed in two parallel series.

Reference substance (positive control):

yes

Remarks:

pottasium dichromate

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

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

Duration:

24 h

Dose descriptor:

NOEC

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

83 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

24 h

Dose descriptor:

EC100

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: not observed
The acute toxicity is monitored as immobilisation of daphnia after 24 and 48 hours. Daphnia is considered as immobile (incapable of swimming) when exhibit no motion during 15 seconds after a gentle agitation of the test container.

Results with reference substance (positive control):

- Results with reference substance valid: yes
- Reference test
The sensitivity of the test species and correctness of test performance is periodically verified in three-month period by testing with the reference substance, potassium dichromate.
The results of the verification test with K2Cr2O7, carried out in period from 2.6. to 4.6.2009 are the following:

24h – EC50 = 2.24 mg/L (95 % confidence limit: 1.89 – 2.60 mg/L)
48h – EC50 = 1.24 mg/L (95 % confidence limit: 1.14 – 1.34 mg/L)

The result of the last interlaboratory test arranged by Centre for Assessment of Laboratories of T.G.Masaryk Water Research Institute Prague in 2008 for potassium dichromate was:
48-hour EC50 = 0.57 – 1.33 mg/L

The immobilisation of test species in reference substance solution expressed as EC50 fits into the accepted range in the interlaboratory tests.

Validity criteria fulfilled:

yes

Conclusions:

Evaluation of results
The highest immobilisation 5 % was observed in limit test. Therefore exact values of EC50 could not be calculated and the values of EC are given in the form of a range. The NOEC and EC100 values are identified by direct observation.
The nominal concentrations of the test substance were used for all evaluations and results.

Test results
24–hour EC50 >100 mg/L (nominal concentration)
48–hour EC50 > 100 mg/L (nominal concentration)

24–hour NOEC = 100 mg/L (nominal concentration)
48–hour NOEC = 83 mg/L (nominal concentration)

24–hour EC100 > 100 mg/L (nominal concentration)
48–hour EC100 > 100 mg/L (nominal concentration)

Executive summary:

The test substance, Semi Dry Absorption (SDA) Product, was tested in acute immobilisation test on daphnia.

The test was performed according to method C.2 – Daphnia sp. Acute Immobilisation Test, Council Regulation (EC) No. 440/2008, published in O.J.L 142, 2008.

Since the test substance is poorly soluble in dilution water at concentrations needed for the test, a stock saturated solution (nominal concentration 100 mg·L-1) of the test substance in dilution water was prepared for preliminary and limit test.

The preliminary test was performed in range of test substance nominal concentrations 1 – 100 mg·L-1. Based on no toxicity of the test substance found in preliminary test, the limit test was performed. The limit test was performed in range of test substance nominal concentrations 62 – 100 mg·L-1. The test was performed as static.

The study was performed without the analytical determination of the test substance concentrations. The nominal concentrations of the test substance were used for all evaluations and results. Only concentrations of metals in stock saturated solution were analysed in the limit test.

Test results:

24–hour EC50 > 100 mg·L-1                           (nominal concentration)

48–hour EC50 > 100 mg·L-1                           (nominal concentration)

24–hour NOEC = 100 mg·L-1                          (nominal concentration)

48–hour NOEC = 83 mg·L-1                           (nominal concentration)

24–hour EC100 > 100 mg·L-1                         (nominal concentration)

48–hour EC100 > 100 mg·L-1                         (nominal concentration)

Classification of the test substance on the basis of hazard to aquatic environment was performed according to the Directive 93/21/EEC, Annex IV (article 5.2.1.).

According to the classification criteria given in quoted Directive the test substance, Semi Dry Absorption (SDA) Product, is not assigned to any of quoted toxicity categories.

Description of key information

The test was performed according to method C.2 – Daphnia sp. Acute Immobilisation Test, Council Regulation (EC) No. 440/2008, published in O.J.L 142, 2008.

GLP Study.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

100 mg/L

Additional information

Test results:

24–hour EC50 > 100 mg·L-1       (nominal concentration)

48–hour EC50 > 100 mg·L-1       (nominal concentration)

24–hour NOEC = 100 mg·L-1       (nominal concentration)

48–hour NOEC = 83 mg·L-1       (nominal concentration)

24–hour EC100 > 100 mg·L-1       (nominal concentration)

48–hour EC100 > 100 mg·L-1       (nominal concentration)

 

Classification of the test substance on the basis of hazard to aquatic environment was performed according to the Directive 93/21/EEC, Annex IV (article 5.2.1.).

According to the classification criteria given in quoted Directive the test substance, Semi Dry Absorption (SDA) Product, is not assigned to any of quoted toxicity categories.