Ashes (residues), cenospheres

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: as the test substance is a complex mixture of individual substances water accommodate fractions (WAFs) were prepared
=> Stock solution: 100 mg/L (saturated solution), volume 10 L
=> stock solution was stirred on a shaft stirrer throughout three days, ultrasonicated for 10 minutes and filtered through 0.45 micron filter.
The concentrations of solutions used in the preliminary and limit test were obtained by dilution of the stock saturated solution with dilution water.
- Differential loading: no
- Controls: yes

Test organisms (species):

Poecilia reticulata

Details on test organisms:

TEST ORGANISM
- Common name: Guppy
- Source: certified supplier BioTest s.r.o., Konárovice (Czech Republic)
- Age at study initiation (mean and range, SD): 3-4 months
- Length at study initiation : 2.0-3.0 cm
- Weight at study initiation (mean and range, SD): 90 mg (mean, beaker 5) - 130 mg (mean, beaker 3)
- Method of breeding: The fish were kept in all-glass aquaria in aerated drinking water
- Feeding during test: no

ACCLIMATION
- Acclimation period: 7 days
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: ad libitum "Tropica" - feed for aquarium fish, sometimes live daphnia (72 h prior to test feeding was stopped)
- Health during acclimation (any mortality observed): healthy animals

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

Preliminary test: Content of (Ca+Mg) ions 2.61 mmol/L
Limit test: Content of (Ca+Mg) ions 2.66 mmol/L

pH:

Preliminary test: 7.6 - 8.0 (based on 100 mg/L and control)
Limit test: 7.5 - 8.1 (based on 100 mg/L and control)

Dissolved oxygen:

Preliminary test: 6.2 - 8.1 mg O2/L (based on 100 mg/L and control)
Limit test: 5.2 - 8.6 mg O2/L (based on 100 mg/L and control)

Nominal and measured concentrations:

Preliminary test: 100%, 50%, 10%, 5%, and 1% of stock solution (100 mg/L)
Limit test: 100%, 91%, 83%, 75%, 68%, and 62% of stock solution (100 mg/L)

Details on test conditions:

all informations reported in this field refer to the limit test

TEST SYSTEM
- Test vessel:
- Type: open
- Material, size, headspace, fill volume: glass beakers, fill volume 2 L
- Aeration: without aeration
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- Biomass loading rate: 0.45 g/L - 0.65 g/L


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: standard dilution water according to ISO 6341-1982 (OECD 203, Annex 2)
- Prior to use the dilution water is aerated up to oxygen saturation.
- Conductivity: 0.154 µS/m


OTHER TEST CONDITIONS
- Adjustment of pH: no
- Photoperiod: natural variation of daylight and darkness
- Light intensity: natural variation of daylight and darkness


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Fish mortality was observed each 24 hours.

TEST CONCENTRATIONS
- Spacing factor for test concentrations: 1.1
- Range finding study
- Test concentrations: 100%, 50%, 10%, 5%, and 1% of stock solution (100 mg/L)

Reference substance (positive control):

yes

Remarks:

(potassium dichromate)

Duration:

96 h

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Duration:

96 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Details on results:

- Behavioural abnormalities: not observed
- Observations on body length and weight: not observed
- Other biological observations: not observed
- Mortality of control: none
- Other adverse effects control: not observed
- Abnormal responses: not observed

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Mortality: yes
- LC50: LC50 (48 h) = 143 mg/L, LC50 (96 h) = 137 mg/L

Sublethal observations / clinical signs:

Limit test       

 

Table 1.Fish mortality – limit test

Nominal concentration	mg·L^-1	100	91	83	75	68	62	C
Saturated solution dosing	mL·L^-1	1000	910	830	750	680	620	C
Number of live fish	2 hours	10	10	10	10	10	10	10
Mortality %	2 hours	0	0	0	0	0	0	0
Number of live fish	24 hours	10	10	10	10	10	10	10
Mortality %	24 hours	0	0	0	0	0	0	0
Number of live fish	48 hours	10	10	10	10	10	10	10
Mortality %	48 hours	0	0	0	0	0	0	0
Number of live fish	72 hours	10	10	10	10	10	10	10
Mortality %	72 hours	0	0	0	0	0	0	0
Number of live fish	96 hours	10	10	10	10	10	10	10
Mortality %	96 hours	0	0	0	0	0	0	0

 

 

Table 2.Concentration of dissolved oxygen and area temperature –limit test

Nominal concentration		mg·L^-1		100		91		83		75		68		62		C		t (°C)
O2(mg·L^-1)		0 hour		5.2		5.1		5.3		5.8		6.1		6.9		8.6		21.0
O2(mg·L^-1)		24 hours		6.5		6.8		6.4		6.9		6.8		6.7		7.0		20.9
O2(mg·L^-1)		48 hours		6.1		6.1		5.5		6.0		5.9		6.6		6.0		21.2
O2(mg·L^-1)		72 hours		6.3		6.3		6.5		6.4		6.5		6.3		6.8		21.0
O2(mg·L^-1)		96 hours		6.9		6.7		6.7		7.1		6.8		6.5		7.0		21.1

 

 

Table 3.pH of solutions– limit test

Nominal concentration	mg·L^-1	100	91	83	75	68	62	C
pH	0 hour	8.1	8.1	8.1	8.1	8.2	8.1	7.9
pH	24 hours	7.7	7.7	7.6	7.7	7.7	7.7	8.0
pH	48 hours	7.5	7.5	7.4	7.5	7.5	7.6	8.0
pH	72 hours	7.5	7.5	7.5	7.5	7.5	7.5	7.7
pH	96 hours	7.5	7.5	7.5	7.5	7.5	7.5	7.6

 

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of this study, the test substance caused no lethal toxicity up to the highest tested concentration of 100 mg/L.

Description of key information

The test substance did not show any toxic effect in the range of water solubility and is not harmful to fish it can be concluded that cenospheres are not harmful to fish.

Additional information

Acute toxicity of a siliceous ash (SiO2 42%) to fish was tested in a GLP-study according to OECD TG 203. A limit test with a loading rate of 100 mg/L was performed on Poecilia reticulata. The tested ash was structural related to ash (residues), cenospheres and as cenospheres are a component of fly ash, these results can be used as read across. After 96 h of exposure no mortality was observed. Based on this loading rate a NOELR of 100 mg/L (nominal value) was determined. As no mortality could be observed the LL50 is defined to be > 100 mg/L (ČEZ Energetické produkty, a. s., 2008).