Refractories, fibers, aluminosilicate

Short-term toxicity to aquatic invertebrates

Administrative data

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2021

Report date:

2021

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

oxo[(oxoalumanyl)oxy]alumane; silanedione

EC Number:

604-314-4

Cas Number:

142844-00-6

Molecular formula:

amorphous glass Si(n)O(3n+1) polymeric anions bonded to Zr and Al(3+)

IUPAC Name:

oxo[(oxoalumanyl)oxy]alumane; silanedione

Test material form:

solid: fibres

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples were taken from the control and the 100 mg/L loading rate WAF test group from the bulk test preparation at 0 hours and from the pooled replicates (Replicates 1 to 4) at 48 hours for quantitative analysis and stored frozen. Duplicate samples of the control and 100 mg/L loading rate WAF test groups were taken and stored frozen for further analysis if necessary.

Test solutions

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- A nominal amount of test item (500 mg) was added to the surface of 5 L 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 95 hours and the mixture allowed to stand for 2 hours. Microscopic observations made on the WAF indicated that long fibers and small sharp crystals were observed to be dispersed in the water column and hence it was considered justifiable to remove the WAF by filtering. At the sponsor’s request, the media was filtered through two glass wool plugs (2 to 4 cm in length) and 2 filter papers. A 10 mL and a 2.0 mL pipette, covered at one end with Nescofilm, were submerged with the vessels (sealed end down to mid-depth within the vessel). A length of Tygon tubing was attached to the 10 mL pipette and the Nescofilm was removed using the 2.0 ml pipette. Two glass wool plugs were inserted into the opposite end of the tubing and the WAF removed by mid-depth siphoning (the first approximately 90 mL discarded) to give the 100 mg/L loading rate WAF. Microscopic observations of the WAF was performed after filtering and showed no micro dispersions to be observed.

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna
- Strain/clone: Straus
- Justification for species other than prescribed by test guideline: Standard as per test guideline
- Age at study initiation (mean and range, SD): Less that 24 hours old
- Weight at study initiation (mean and range, SD): Not specified
- Length at study initiation (length definition, mean, range and SD): Not specified
- Stage and instar at study initiation: First instar
- Method of breeding: Obtained from in house cultures and conditions ensured that reproduction was by parthenogenesis.
- Source: In-house cultures
- Age of parental stock (mean and range, SD): Not specified
- Feeding during test
- Food type: No feeding during test

ACCLIMATION
- Acclimation period: Not specified
- Acclimation conditions (same as test or not): Same as test
- Type and amount of food: Each culture was fed with a mixture of algal suspension (Raphidocelis subcapitata) and GEMMA Micro 300 fish 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, INCLUDING CULTURING CONDITIONS: Gravid adults were isolated the day before initiation of the test, such that the young daphnids produced overnight were less than 24 hours old.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Remarks on exposure duration:

Standard as per OECD guideline

Post exposure observation period:

Not required

Test conditions

Hardness:

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

Test temperature:

Maintained at approximately 18 to 22°C throughout the test

pH:

Control: 7.4 to 8.3
Test (100 mg/L): 7.5 to 8.2

Dissolved oxygen:

Control: 9 to 9.1 mg O2/L
Test (100 mg/L): 8.6 to 8.8 mg O2/L

Salinity:

Not specified

Conductivity:

Not specified

Nominal and measured concentrations:

Nominal: Control and 100 mg/L (nominal loading rate)
Measured: Chemical analysis of the fresh test preparations at 0 hours showed measured test concentrations of 0.11 mg/L as Aluminium. Chemical analysis of the aged test preparations at 48 hours showed measured test concentrations of 0.087 mg/L as Aluminium. The dissolved test item may have been one or several components of the test item. Given that the toxicity cannot be attributed to a single component or a mixture of components, but to the test item as a whole, the results were based on nominal loading rates only.

Details on test conditions:

TEST SYSTEM
- Test vessel: 150 mL glass vessels
- Type (delete if not applicable): open although covered to reduce evaporation
- Material, size, headspace, fill volume: 150 mL vessels containing 100 mL of test or control preparations.
- Volume of solution: 100 mL
- 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 the range-finding and definitive tests. The reconstituted water had a pH of 7.8 ±0.2 adjusted (if necessary) with NaOH or HCl and was aerated until the dissolved oxygen concentration was approximately air-saturation value. The reconstituted water had an approximate theoretical total hardness of 250 mg/L as CaCO3.

OTHER TEST CONDITIONS
- Adjustment of pH: Only where necessary in stock water
- Photoperiod: The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods.
- Light intensity: between 200 and 1200 Lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Any immobilization or adverse reactions to exposure were recorded at 24 and 48 hours after the start of exposure. The criterion of effect used was that Daphnia were considered to be immobilized if they were unable to swim within 15 seconds after gentle agitation.

VEHICLE CONTROL PERFORMED: No as no vehicle utilised

RANGE-FINDING STUDY
- Test concentrations: Control, 1, 10 and 100 mg/L loading rates.
- Results used to determine the conditions for the definitive study: No 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 significant immobilization was observed. Chemical analysis of the test preparations at 0 hours showed measured test concentrations of 0.015 to 0.058 mg/L as Aluminium. There was no significant change in the measured concentration to be tested at 48 hours indicating that the test item was stable at this level under test conditions.

Reference substance (positive control):

yes

Remarks:

Potassium dichromate

Results and discussion

Effect concentrations

Duration:

48 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (total fraction)

Basis for effect:

mobility

Details on results:

Verification of test solutions:
Chemical analysis of the fresh test preparations at 0 hours showed measured test concentrations of 0.11 mg/L as Aluminium. Chemical analysis of the aged test preparations at 48 hours showed measured test concentrations of 0.087 mg/L as Aluminium. The dissolved test item may have been one or several components of the test item. Given that the toxicity cannot be attributed to a single component or a mixture of components, but to the test item as a whole, the results were based on nominal loading rates only.

Immobilisation data:
There was no immobilization in 20 daphnids exposed to a 100 mg/L loading rate WAF for a period of 48 hours.

Sub-lethal effects: No sub-lethal effects of exposure were observed throughout the test.

Vortex depth measurements: The vortex depth was recorded at the start and end of the mixing period and was observed to be a dimple at the water surface on each occasion.

Observations of test item solubility: Observations on the test media were carried out during the mixing and testing of the WAF. At the start of the mixing period the 100 mg/L preparation was observed to be a very cloudy dispersion. After 95 hours stirring and a 2-Hour standing period the 100 mg/L preparation was observed to be a cloudy dispersion with particles of fine grey solid at the surface of the media and at the bottom of the vessel. Microscopic examination of the WAF showed long fibers and small sharp crystals dispersed in the water column and therefore it was considered justifiable to remove the WAF by filtering. At the sponsor’s request, the media was filtered through two glass wool plugs (2 to 4 cm in length) and 2 filter papers. Microscopic examination after filtering showed the glass wool plug had removed all visible micro dispersions.

At the start and throughout the test all control and test solutions were observed to be clear colorless solutions.

Results with reference substance (positive control):

A positive control study used potassium dichromate as the reference item at concentrations of 0.32, 0.56, 1.0, 1.8 and 3.2 mg/L. The positive control was conducted between 05 January 2021 and 29 January 2021 and provided a 48 hour EC50 of 0.50 mg/L.

Analysis of the immobilization data was carried out using the Weibull analysis using linear maximum-likelihood regression at 24 and 48 hours. All statistical analysis was carried out using the ToxRat Professional computer software package. The results from the positive control with potassium dichromate were within the normal range for this reference item.

Reported statistics and error estimates:

Due to the nature of the data it was not possible to calculate the slope and error of response curve at 24 and 48 hours.

Any other information on results incl. tables

Cumulative immobilisation observed in the definitive test:

Nominal Loading Rate (mg/L)	48 hours
	Cumulative Immobilized Daphnia (Initial Population: 5 Per Replicate)						Observations
	R1	R2	R3	R4	Total	%	R1	R2	R3	R4
Control	0	0	0	0	0	0	5N	5N	5N	5N
100	0	0	0	0	0	0	5N	5N	5N	5N

Analytical results of test samples

Time point (hours)	Nominal concentration of test item in sample (mg/L WAF)	Determined concentration of aluminium in test sample (mg/L Al)	Percentage of nominal concentration (%)
0	Control	ND	-
	100	0.105	-
48	Control	<LOQ	-
	100	0.0866	-
P. Rec 1	0.0250	0.0191	76
P. Rec 2	0.0250	0.0187	75

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The test was considered to be valid given that none of the control daphnids showed immobilization or other signs of disease or stress and that the oxygen concentration at the end of the test was equal to or greater than 3 mg/L in the control/test vessels.

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 rate was 100 mg/L loading rate WAF.