Trialuminium bismuth hexaoxide

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:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 850.1010 (Aquatic Invertebrate Acute Toxicity Test, Freshwater Daphnids)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

- Concentrations: Nominal loading rate of 100 mg/L
- Sampling method: Samples were taken from the control and the test group from the bulk test preparation at 0 and 24 hours and from the pooled replicates (R1 to R4) at 24 and 48 hours for quantitative analysis. Samples were stored frozen prior to analysis. Duplicate sets of samples were taken at 0, 24 and 48 hours and stored frozen for further analysis if necessary.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Due to the low aqueous solubility and complex nature of the test item, for the purposes of the study the test medium was prepared as a WAF of the test item. A nominal amount of test item (200 mg) was each separately added to the surface of 2 liters of test water to give the 100 mg/L loading rate. After the addition of the test item, the test water was stirred by magnetic stirrer using a stirring rate such that a vortex was formed to give a dimple at the water surface. The stirring was stopped after 23 hours and the mixture allowed to stand for 1 hour. Visual observations made on the WAF indicated that a significant amount of dispersed test item was present in the water column and hence it was considered justifiable to remove the insoluble test article by filtering through a glass wool plug (2 to 4 cm in length). A wide bore glass tube, covered at one end with Nescofilm was submerged into the vessel, sealed end down, to a depth of approximately 5 cm from the bottom of the vessel. A length of Tygon tubing was inserted into the glass tube and pushed through the Nescofilm seal. A glass wool plug was inserted into the opposite end of the tubing and the WAF removed by mid depth siphoning (the first 75 to 100 mL discarded) to give the 100 mg/L loading rate WAF. Microscopic observations of the WAF were performed after filtering and showed no test item observed.

- Controls: Media without test substance

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone:
- Source:
- Age of parental stock (mean and range, SD):
- Feeding during test: No
- Food type: NA
- Amount: NA
- Frequency: NA

ACCLIMATION
- Acclimation period:
- Acclimation conditions (same as test or not): Same as test
- Type and amount of food: Mixture of algal suspension (Desmodesmus subspicatus) and Tetramin® flake food suspension.
- Feeding frequency: Daily
- Health during acclimation (any mortality observed): None noted


METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old. These young were removed from the cultures and used for testing.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Hardness:

The reconstituted water had an approximate theoretical total hardness of 250 mg/L as CaCO3

Test temperature:

21 to 22°C in test replicates and controls

pH:

7.8 to 8.1 in test replicates
7.7 to 8.0 in controls

Dissolved oxygen:

8.4 to 8.9 mgO2/L in test replicates
8.4 t 9.0 mgO2/L in control replicates

Salinity:

Not specified

Conductivity:

Not specified

Nominal and measured concentrations:

Nominal loading rates: 0 and 100 mg/L
Measured concentrations: Varied based on both Bismuth and Aluminium ion calculations

Details on test conditions:

TEST SYSTEM
- Test vessel: Glass jars
- Type: open (test vessels covered to reduce evaporation)
- Material, size, headspace, fill volume: 150 mL jars containing 100 mL of test preparations.
- Aeration: No
- No. of organisms per vessel: 5
- No. of vessels per concentration (replicates): 4
- No. of vessels per control (replicates): 4
- Biomass loading rate: Not specified

TEST MEDIUM / WATER PARAMETERS
- Reconstituted water (ISO media) used for both the range finding and definitive. This is standard as per the OECD guidelines.

OTHER TEST CONDITIONS
- Adjustment of pH: None
- Photoperiod: 16 hours light, 8 hours dark cycle
- Light intensity: Between 930 and 1052 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : immobilisation (unable to swim within 15 seconds of gentle agitation) and sub-lethal effects at 24 and 48 hours.

VEHICLE CONTROL PERFORMED: no

RANGE-FINDING STUDY
- Test concentrations: 1, 10 and 100 mg/L loading rates
- Results used to determine the conditions for the definitive study: No immobilization or sub lethal effects of exposure were observed throughout the test. Based on this information a single loading rate of four replicates of 100 mg/L, was selected for the definitive test. This experimental design conforms to a "Limit test" to confirm that no immobilization or adverse reactions to exposure were observed.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOELR

Effect conc.:

100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

mobility

Details on results:

- Behavioural abnormalities: During the test, one daphnia out of 20 in the 100 mg/L loading rate WAF group was observed to be covered in debris.
- Observations on body length and weight: Not conducted
- Other biological observations: None noted
- Mortality of control: 5% (< 10%)
- Other adverse effects control: None noted
- Abnormal responses: None noted
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: No microdispersions of test substance noted and test media appeared clear and colourless although this cannot be conclusively ruled out (i.e. undissolved meterial may have remained).
- Effect concentrations exceeding solubility of substance in test medium: Given that the toxicity cannot be attributed to a single component or a mixture of components (e.g. dissociated ions) but to the test item as a whole, the results were based on nominal loading rates only.

Results with reference substance (positive control):

- Results with reference substance valid: Yes
- Relevant effect levels: 48 hour EC50 and NOEC
- Limit test: No
- Dose-response test: Yes (0.32, 0.56, 1.0, 1.8 and 3.2 mg/L).
- ECx: 0.75 mg/L
- NOEC: 0.56 mg/L

Reported statistics and error estimates:

An estimate of the EL50 values was given by inspection of the immobilization data.

For the estimation of the NOEL the number of immobilized daphnids for the control and 100 mg/L loading rate WAF group were compared using the Fisher’s Exact Binomial Test performed using the ToxRatPro software package (TOXRAT).

Cumulative Immobilisation data:

Nominal Loading Rate (mg/L)	24 Hours
	Cumulative Immobilized Daphnia (Initial Population: 5 Per Replicate)						Observations
	Rep1	Rep2	Rep3	Rep4	Total	%	Rep1	Rep2	Rep3	Rep4
Control	0	0	0	1	1	5	5N	5 N	5 N	4 N
100	0	0	0	0	0	0	5 N	5 N	5 N	5 N
Nominal Loading Rate (mg/L)	48 Hours
	Cumulative Immobilized Daphnia (Initial Population: 5 Per Replicate)						Observations
	Rep1	Rep2	Rep3	Rep4	Total	%	Rep1	Rep2	Rep3	Rep4
Control	0	0	0	1	1	5	5 N	5 N	5 N	4 N
100	0	0	0	0	0	0	4 N 1 C	5 N	5 N	5 N

Rep = Replicate

C = Covered with debris

N = Normal

Analytical results for Test Samples:

Time Point	Nominal Loading Rate	Sample Preparation Factor	Determined Concentration of Aluminium	Determined Concentration of Bismuth	Calculated Concentration of Test Item (based on Bismuth)
	cnom	F	c	c	c
[Hours]	[mg/L]		[mg/LAl]	[mg/LBi]	[mg/L]
0	Control	1.02	0.0158	<LOQ	<LOQ
	100	1.02	0.0910	0.222	0.512
24	Control	1.02	<LOQ	<LOQ	<LOQ
(old)	100	1.02	0.0522	0.0908	0.209
24	Control	1.02	<LOQ	<LOQ	<LOQ
(fresh)	100	1.02	0.0728	0.0468	0.108
48	Control	1.02	<LOQ	<LOQ	<LOQ
(old)	100	1.02	0.0674	0.0331	0.0762

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of the test item to the freshwater invertebrate Daphnia magna has been investigated and gave a 48 Hour EL50 value of greater than 100 mg/L loading rate WAF. The NOEL was 100 mg/L loading rate WAF.

Description of key information

A reliable OECD guideline study assessing the acute toxicity of the substance to Daphnia magna is available. This provides a 48 hour EL50 value of > 100 mg/L. As such no value is included as key for chemical safety assessment as the effect level was determined to be greater than the limit test concentration for tests of this type.