Synthetic wollastonite

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

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

Adequacy of study:

key study

Study period:

The study was conducted between 9 May 2010 and 06 July 2010

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Justification for type of information:

The use of data derived for Soda-ash flux calcined kieselghur are justified for read-across to
synthetic wollastonite. Justification for read-across is warranted given the similarities in toxicity profile and physico-chemical properties for Soda-ash flux calcined kieselghur and synthetic wollastonite.
Considering the available data:
The source substance show no concerns for the environment.
The source substance has low acute toxicity and low toxicity in repeated dose studies, is non-irritant (skin and eye), non-sensitizing, non-mutagenic to bacteria, non-cytogenic and has low toxicity for reproductive and developmental toxicity.
Please see RAAF attached in Section 13. for further details.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Water samples were taken from the control and each replicate test vessel at 0 (fresh media), 24, 48, 72 (fresh and old media) and 96 hours (old media) for quantitative analysis. Water samples were stored at approximately 4ºC prior to analysis.

Duplicate samples were taken and stored at approximately -20C for further analysis if necessary.

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Preliminary solubility work conducted indicated that the test item was practically insoluble in water using traditional methods of preparation e.g. ultrasonication and high shear mixing.
Based on this information the test item was categorised as being a ‘difficult substance’ as defined by the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (OECD 2000).
An amount of test item (550 mg) was dispersed in 11 litres of reconstituted water with the aid of a propeller stirrer at approximately 1500 rpm at a temperature of approximately 14°C for 24 or 48 hours. After the stirring period, the undissolved test item was removed by filtration through a 0.2 µm Gelman Acrocap filter (first approximate 100 ml discarded to pre-condition the filter) to give the 100% v/v saturated solution.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

- Source: Brow Well Fisheries Limited, Hebden, near Skipton, Yorkshire, UK
- Age at study initiation (mean and range, SD): Juvenile
- Length at the end of the definitive test: mean length 5.5cm (sd = 0.3)
- Weight at the end of the definitive test: mean weight 0.85 g ( sd = 0.59)
- Feeding during test: No, feeding was discontinued 24 h prior to the start of the test

ACCLIMATION
- Acclimation period: From 4 May 2010 to 17 May 2010
- Acclimation conditions (same as test or not): Fish were maintained in a glass fibre tank with a "single pass" water renewal system. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods. The water temperature was controlled at approximately 14 °C with a dissolved oxygen content of greater than or equal to 10.2 mg O2/L.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

Approximately 140 mg/l as CaCO3

Test temperature:

Control: 13 - 15°C
Test vessels: 14 - 15°C

pH:

Control: 8.0 - 8.4
Test vessels: 8.1 - 8.6

Dissolved oxygen:

Control: 92-99% ASV (air saturation value)
Test vessels: 91 - 101% ASV

Nominal and measured concentrations:

Nominal concentration: 100% v/v saturated solution.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 20 L glass exposure vessels
- Aeration: The test vessels were aerated via narrow bore glass tubes.
- Renewal rate of test solution (frequency/flow rate): A semi-static test regime was employed in the test involving a daily renewal of the test preparations to ensure that the concentrations of the test item remained near nominal and to prevent the build up of nitrogenous waste products.
- No. of organisms per vessel: 7 fish/ vessel
- No. of vessels per concentration (replicates): 2 replicates
- No. of vessels per control (replicates): 1 control vessel
- Biomass loading rate: 0.79 g bodyweight/litre

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory tap water was dechlorinated by passage through an activated carbon filter and partly softened giving water with a total hardness of approximately 140 mg/L as CaCO3. After dechlorination and softening the water was passed through a series of computer controlled plate heat exchangers to achieve the required temperature.
- Total organic carbon: 1.018 mg/L (average)
- Chlorine: Average free chlorine = 0.248 mg/L; Average total chlorine = 0.307 mg/L
- Alkalinity: pH = 7.624 (average)
- Conductivity: 386.192 µS/cm at 20 °C (average)
- Culture medium different from test medium: No
- Intervals of water quality measurement: The water temperature, pH and dissolved oxygen concentrations were recorded daily throughout the test.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods

EFFECT PARAMETERS MEASURED: Any mortalities and sub-lethal effects of exposure were recorded at 3, 6, 24, 48, 72 and 96 hours after the start of exposure. The criteria of death were taken to be the absence of both respiratory movement and response to physical stimulation.

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: In the range-finding test fish were exposed to a single test concentration of 100% v/v saturated solution. A single concentration was used as results from the range-finding test for the Acute Toxicity to Daphnia magna test (Harlan Laboratories Ltd. Project Number 3018/0012) indicated toxicity was not expected at this concentration. The test item was prepared as a saturated solution.
- Results used to determine the conditions for the definitive study: There were no sub-lethal effects of exposure during the range-finding test.
The results showed no mortalities at the test concentration of 100% v/v saturated solution.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 other: % v/v saturated solution

Nominal / measured:

nominal

Conc. based on:

other: saturated solution of test material

Details on results:

There were no mortalities in 14 fish exposed to a test concentration of 100% v/v saturated solution for a period of 96 hours.
There were no sub-lethal effects of exposure observed in 14 fish exposed to a test concentration of 100% v/v saturated solution for a period of 96 hours.
The test preparations were observed to be clear, colourless solutions throughout the duration of the test

Sublethal observations / clinical signs:

Table1: Cumulative Mortality Data in the Range-findingTest

Nominal Concentration (% v/v Saturated Solution)	Cumulative Mortality (Initial Population = 3)
	3 Hours	6 Hours	24 Hours	48 Hours	72 Hours	96 Hours
Control	0	0	0	0	0	0
100	0	0	0	0	0	0

Table 2: Cumulative mortality data in the definitive test

Nominal Concentration (% v/v Saturated Solution)	Cumulative Mortality (Initial Population =7)						% Mortality
	3 Hours	6 Hours	24 Hours	48 Hours	72 Hours	96 Hours	96 Hours
Control	0	0	0	0	0	0	0
100 R1	0	0	0	0	0	0	0
100 R2	0	0	0	0	0	0	0

R₁and R₂= Replicates 1 and 2

Table 3: Physico-chemical measurements

Nominal Concentration (% v/v Saturated Solution)	Time (Hours)
	0 Hours (Fresh Media)				24 Hours (Old Media)				24 Hours (Fresh Media)
	pH	mg O2/l	%ASV*	TºC	pH	mg O2/l	%ASV*	T°C	pH	mg O2/l	%ASV*	T°C
Control	8.1	10.2	97	13	8.4	9.5	92	14	8.0	10.4	99	13
100 R1	8.2	10.3	100	14	8.3	9.3	90	14	8.1	10.4	101	14
100 R2	8.2	10.0	97	14	8.3	9.5	92	14	8.1	10.4	101	14

Nominal Concentration (% v/v Saturated Solution)	Time (Hours)
	48 Hours (Old Media)				48 Hours (Fresh Media)				72 Hours (Old Media)
	pH	mg O2/l	%ASV*	TºC	pH	mg O2/l	%ASV*	T°C	pH	mg O2/l	%ASV*	T°C
Control	8.1	9.3	92	15	8.0	10.7	104	14	8.4	9.6	93	14
100 R1	8.4	9.4	91	14	8.2	10.5	102	14	8.5	9.3	92	15
100 R2	8.3	9.6	95	15	8.2	10.5	102	14	8.6	9.8	95	14

Nominal Concentration (% v/v Saturated Solution)	Time (Hours)
	72 Hours (Fresh Media)				96 Hours (Old Media)
	pH	mg O2/l	%ASV*	TºC	pH	mg O2/l	%ASV*	T°C
Control	7.9	11.0	108	14	8.3	10.0	97	14
100 R1	8.1	10.5	102	14	8.6	10.1	98	14
100 R2	8.1	10.7	104	14	8.4	9.4	91	14

*ASV= Dissolved oxygen concentration expressed as a percentage of Air Saturation Value

Validity criteria fulfilled:

yes

Remarks:

All validity criteria were satisfied

Conclusions:

The acute toxicity of the read-across material Soda-ash flux calcined kieselghur to the freshwater fish rainbow trout (Oncorhynchus mykiss) has been investigated and gave a 96-Hour LC50 of greater than 100% v/v saturated solution. Correspondingly the No Observed Effect Concentration was 100% v/v saturated solution.

Justification for read-across is warranted given the similarities in toxicity profile and physico-chemical properties for Soda-ash flux calcined kieselghur and synthetic wollastonite.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 9 May 2010 and 06 July 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 203 (Fish, Acute Toxicity Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Details on sampling:

Water samples were taken from the control and each replicate test vessel at 0 (fresh media), 24, 48, 72 (fresh and old media) and 96 hours (old media) for quantitative analysis. Water samples were stored at approximately 4ºC prior to analysis.

Duplicate samples were taken and stored at approximately -20C for further analysis if necessary.

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
Preliminary solubility work conducted indicated that the test item was practically insoluble in water using traditional methods of preparation e.g. ultrasonication and high shear mixing.
Based on this information the test item was categorised as being a ‘difficult substance’ as defined by the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures (OECD 2000).
An amount of test item (550 mg) was dispersed in 11 litres of reconstituted water with the aid of a propeller stirrer at approximately 1500 rpm at a temperature of approximately 14°C for 24 or 48 hours. After the stirring period, the undissolved test item was removed by filtration through a 0.2 µm Gelman Acrocap filter (first approximate 100 ml discarded to pre-condition the filter) to give the 100% v/v saturated solution.

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

- Source: Brow Well Fisheries Limited, Hebden, near Skipton, Yorkshire, UK
- Age at study initiation (mean and range, SD): Juvenile
- Length at the end of the definitive test: mean length 5.5cm (sd = 0.3)
- Weight at the end of the definitive test: mean weight 0.85 g ( sd = 0.59)
- Feeding during test: No, feeding was discontinued 24 h prior to the start of the test

ACCLIMATION
- Acclimation period: From 4 May 2010 to 17 May 2010
- Acclimation conditions (same as test or not): Fish were maintained in a glass fibre tank with a "single pass" water renewal system. The lighting cycle was controlled to give a 16 hours light and 8 hours darkness cycle with 20 minute dawn and dusk transition periods. The water temperature was controlled at approximately 14 °C with a dissolved oxygen content of greater than or equal to 10.2 mg O2/L.

Test type:

semi-static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

96 h

Hardness:

Approximately 140 mg/l as CaCO3

Test temperature:

Control: 13 - 15°C
Test vessels: 14 - 15°C

pH:

Control: 8.0 - 8.4
Test vessels: 8.1 - 8.6

Dissolved oxygen:

Control: 92-99% ASV (air saturation value)
Test vessels: 91 - 101% ASV

Nominal and measured concentrations:

Nominal concentration: 100% v/v saturated solution.

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Type (delete if not applicable): closed
- Material, size, headspace, fill volume: 20 L glass exposure vessels
- Aeration: The test vessels were aerated via narrow bore glass tubes.
- Renewal rate of test solution (frequency/flow rate): A semi-static test regime was employed in the test involving a daily renewal of the test preparations to ensure that the concentrations of the test item remained near nominal and to prevent the build up of nitrogenous waste products.
- No. of organisms per vessel: 7 fish/ vessel
- No. of vessels per concentration (replicates): 2 replicates
- No. of vessels per control (replicates): 1 control vessel
- Biomass loading rate: 0.79 g bodyweight/litre

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Laboratory tap water was dechlorinated by passage through an activated carbon filter and partly softened giving water with a total hardness of approximately 140 mg/L as CaCO3. After dechlorination and softening the water was passed through a series of computer controlled plate heat exchangers to achieve the required temperature.
- Total organic carbon: 1.018 mg/L (average)
- Chlorine: Average free chlorine = 0.248 mg/L; Average total chlorine = 0.307 mg/L
- Alkalinity: pH = 7.624 (average)
- Conductivity: 386.192 µS/cm at 20 °C (average)
- Culture medium different from test medium: No
- Intervals of water quality measurement: The water temperature, pH and dissolved oxygen concentrations were recorded daily throughout the test.

OTHER TEST CONDITIONS
- Photoperiod: 16 hours light and 8 hours darkness with 20 minute dawn and dusk transition periods

EFFECT PARAMETERS MEASURED: Any mortalities and sub-lethal effects of exposure were recorded at 3, 6, 24, 48, 72 and 96 hours after the start of exposure. The criteria of death were taken to be the absence of both respiratory movement and response to physical stimulation.

TEST CONCENTRATIONS
- Range finding study
- Test concentrations: In the range-finding test fish were exposed to a single test concentration of 100% v/v saturated solution. A single concentration was used as results from the range-finding test for the Acute Toxicity to Daphnia magna test (Harlan Laboratories Ltd. Project Number 3018/0012) indicated toxicity was not expected at this concentration. The test item was prepared as a saturated solution.
- Results used to determine the conditions for the definitive study: There were no sub-lethal effects of exposure during the range-finding test.
The results showed no mortalities at the test concentration of 100% v/v saturated solution.

Reference substance (positive control):

no

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 other: % v/v saturated solution

Nominal / measured:

nominal

Conc. based on:

other: saturated solution of test material

Details on results:

There were no mortalities in 14 fish exposed to a test concentration of 100% v/v saturated solution for a period of 96 hours
There were no sub-lethal effects of exposure observed in 14 fish exposed to a test concentration of 100% v/v saturated solution for a period of 96 hours.
The test preparations were observed to be clear, colourless solutions throughout the duration of the test

Sublethal observations / clinical signs:

Table1: Cumulative Mortality Data in the Range-findingTest

Nominal Concentration (% v/v Saturated Solution)	Cumulative Mortality (Initial Population = 3)
	3 Hours	6 Hours	24 Hours	48 Hours	72 Hours	96 Hours
Control	0	0	0	0	0	0
100	0	0	0	0	0	0

Table 2: Cumulative mortality data in the definitive test

Nominal Concentration (% v/v Saturated Solution)	Cumulative Mortality (Initial Population =7)						% Mortality
	3 Hours	6 Hours	24 Hours	48 Hours	72 Hours	96 Hours	96 Hours
Control	0	0	0	0	0	0	0
100 R1	0	0	0	0	0	0	0
100 R2	0	0	0	0	0	0	0

R₁and R₂= Replicates 1 and 2

Table 3: Physico-chemical measurements

Nominal Concentration (% v/v Saturated Solution)	Time (Hours)
	0 Hours (Fresh Media)				24 Hours (Old Media)				24 Hours (Fresh Media)
	pH	mg O2/l	%ASV*	TºC	pH	mg O2/l	%ASV*	T°C	pH	mg O2/l	%ASV*	T°C
Control	8.1	10.2	97	13	8.4	9.5	92	14	8.0	10.4	99	13
100 R1	8.2	10.3	100	14	8.3	9.3	90	14	8.1	10.4	101	14
100 R2	8.2	10.0	97	14	8.3	9.5	92	14	8.1	10.4	101	14

Nominal Concentration (% v/v Saturated Solution)	Time (Hours)
	48 Hours (Old Media)				48 Hours (Fresh Media)				72 Hours (Old Media)
	pH	mg O2/l	%ASV*	TºC	pH	mg O2/l	%ASV*	T°C	pH	mg O2/l	%ASV*	T°C
Control	8.1	9.3	92	15	8.0	10.7	104	14	8.4	9.6	93	14
100 R1	8.4	9.4	91	14	8.2	10.5	102	14	8.5	9.3	92	15
100 R2	8.3	9.6	95	15	8.2	10.5	102	14	8.6	9.8	95	14

Nominal Concentration (% v/v Saturated Solution)	Time (Hours)
	72 Hours (Fresh Media)				96 Hours (Old Media)
	pH	mg O2/l	%ASV*	TºC	pH	mg O2/l	%ASV*	T°C
Control	7.9	11.0	108	14	8.3	10.0	97	14
100 R1	8.1	10.5	102	14	8.6	10.1	98	14
100 R2	8.1	10.7	104	14	8.4	9.4	91	14

*ASV= Dissolved oxygen concentration expressed as a percentage of Air Saturation Value

Validity criteria fulfilled:

yes

Remarks:

All validity criteria were satisfied

Conclusions:

The acute toxicity of the test item to the freshwater fish rainbow trout (Oncorhynchus mykiss) has been investigated and gave a 96-Hour LC50 of greater than 100% v/v saturated solution. Correspondingly the No Observed Effect Concentration was 100% v/v saturated solution.

Description of key information

An acute toxicity study to rainbow trout has not been carried out on Synthetic Wollastonite. A study has been carried out on the analogue substance kieselguhr soda ash flux calcined. The study was carried out to GLP study in accordance with OECD Guideline 203. The 96 h EC50 was >100% v/v saturated solution and the NOEC was 100% v/v saturated solution.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Dose descriptor:

EC50

Remarks:

>100% v/v saturated solution; NOEC was 100% v/v saturated solution

Additional information

The key study (Priestly 2010) was performed to OECD Guideline 203 and in accordance with GLP. The study assessed the acute toxicity torainbow trout in a limit test. Pre-study solubility work indicated that a solution of the test item could not be attained using conventional methods, for example, ultrasonication or high shear mixing. Given the insoluble nature of the test item and also its high purity value, it was considered that the most suitable method of preparation was as a saturated solution. Following a preliminary range-finding test fish were exposed, in two groups of seven, to an aqueous solution of the test item, at a single concentration of 100 % v/v saturated solution for a period of 96 hours. The number of mortalities and any sub-lethal effects of exposure in each test and control vessel were determined 3 and 6 hours after the start of exposure and then daily throughout the test until termination after 96 hours. The 96-Hour LC₅₀based on nominal test concentrations was greater than 100% v/v saturated solution and correspondingly the No Observed Effect Concentration was 100 % v/v saturated solution.

Justification for read-across is warranted given the similarities in toxicity profile and physico-chemical properties for Soda-ash flux calcined kieselghur and synthetic wollastonite.