Ashes (residues), cenospheres

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

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 202 (Daphnia sp. Acute Immobilisation 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 two 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):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: water flea
- Source: own laboratory breeding
- Age at study initiation: < 24 hours
- Method of breeding: aperiodic parthenogenesis
- Feeding during test: no
- Lighting: natural variation of daylight and darkness
- Number of test animals: 20 animals/test concentration and control (in preliminary test and limit test)
- Aeration: without aeration


ACCLIMATION
- Acclimation period: not specified (Adult gravid females are separated into dilution water. Young daphnia less than 24 hours are segregated to the handling container from which they entered the experiment.)
- Acclimation conditions: same as test
- Type and amount of food: a mixture of algae

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

Preliminary test: content of (Ca+Mg) ions 2.61 mmol/L
Limit test: content of (Ca+Mg) ions 2.59 mmol/L

Test temperature:

Preliminary test: 19.6 °C - 19.8 °C
Limit test: 19.6 °C - 19.7 °C

pH:

Preliminary test: 7.8 - 8.0 (based on 100 mg/L and control)
Limit test: 7.4 - 8.0 (based on 100 mg/L and control)

Dissolved oxygen:

Preliminary test: 4.6 - 9.2 mg O2/L (based on 100 mg/L and control)
Limit test: 7.6 - 9.1 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, fill volume: glass beakers, 50 mL of test solution
- Aeration: no
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: 1 daphnia / 5 mL


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: standard dilution water according to ISO 6341-1982 (OECD 202, Annex 2)
- Conductivity: 0.135 µS/m
- Intervals of water quality measurement: only once before the test


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) :
- The acute toxicity is monitored by immobilisation of Daphnia magna after 24 and 48 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:

(pottasium dichromate)

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

>= 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

LL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

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

Results with reference substance (positive control):

- Results with reference substance valid? yes
- Mortality: yes
- EC50: EC50 (24 h) = 1.15 mg/L, EC50 (48 h) = 0.8 mg/L

Limit test

 

Table 1.Immobilisation of daphnia – 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 animals	24 hours/1^stseries	10	10	10	10	10	10	10
Number of live animals	24 hours/2^ndseries	10	10	10	10	10	10	10
Number of live animals	24 hours/total	20	20	20	20	20	20	20
Immobilisation %	24 hours	0	0	0	0	0	0	0
Number of live animals	48 hours/1^stseries	10	10	10	10	10	10	10
Number of live animals	48 hours/2^ndseries	10	10	10	10	10	10	10
Number of live animals	48 hours/total	20	20	20	20	20	20	20
Immobilisation %	48 hours	0	0	0	0	0	0	0

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

Nominal concentration	mg·L^-1	100	91	83	75	68	62	C	t°C
O2(mg·L^-1)	0 hour	7.6	8.0	8.2	8.3	8.4	8.6	9.1	19.7
O2(mg·L^-1)	48 hours	8.9	8.9	9.0	9.2	9.1	9.1	8.9	19.6

 

Table 3.pH of solutions – limit test

Nominal concentration	mg·L^-1	100	91	83	75	68	62	C
pH	0 hour	7.4	7.5	7.5	7.5	7.5	7.8	8.0
pH	48 hours	7.9	7.9	7.9	8.0	8.0	8.0	8.0

Validity criteria fulfilled:

yes

Conclusions:

No immobilisation was observed in the limit test, concluding that the test substance is not acute toxic to Daphnia magna at a concentration of 100 mg/L.

Description of key information

The test substance is not harmful to aquatic invertebrates and it can be regarded that cenospheres has no harmful effects on invertebrates.

Additional information

One limit tests according to OECD TG 202 water accommodate fractions (WAFs) of fly ash was prepared. The toxicity of the soluble fractions of the ash contained in the WAFs was assessed by observations on the mobility of Daphnia magna. After a testing period of 48 hours no adverse effects could be determined up to the loading rate of 100 mg/L. The tested fly 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. The EL50 could not be determined as they were beyond the range tested, exceeding a loading rate of 100 mg/L. NOEL for ash equalled a loading rate of >= 100 mg/L. Based on these findings the substance is not to be harmful to Daphnia magna and it can be concluded that cenospheres are also not harmful to aquatic invertebrates.