RAL 3.0

Toxicity to aquatic algae and cyanobacteria

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Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Remarks:

One GLP-compliant guideline study (OECD 201) in which the concentrations were analytically verified is available for toxicity in algae. (Solvay, 2008b). It was a static test and analytical monitoring has been performed.

Adequacy of study:

key study

Study period:

2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP compliant, guideline study, available as unpublished report, no restrictions, fully adequate for assessment

Cross-reference

Reason / purpose for cross-reference:

read-across source

Remarks:

In the following is the data from the study available to determine the short-term toxicity of trisodium hexafluoroaluminate on aquatic algae.

Reference

No studies are available to determinate the toxicity to aquatic plants other than algae, of trisodium hexafluoroaluminate or calcium fluoride. Available studies on fluoride were used as read-across source. Effective concentrations were recalculated taking in account the different molecular weight of the source and target substance.

A 7 -day study was conducted on Lemna minor to assess the toxicity of fluoride in the presence of chloride and in hard water. Lemna minor was found to be relatively insensitive to fluoride with an IC50 value (frond number) of 391 mg/L F. This relates to 803.39 mg CaF2/L. and relates to 720 mg Na3AlF6/L

 

Reliable acute ecotoxicity test results are available for fish, invertebrates and algae. The 96-h LC50 in Brachydanio rerio is 99 mg/l from a GLP compliant OECD guideline study (Solvay, 2008a). An OECD guideline study is available for short-term toxicity in invertebrates, the 48-h EC50 in Daphnia magna is 156 mg/l (IWL, 1998). The 72-h ErC50 is 8.8 mg/l in the freshwater algae Pseudokirchneriella subcapitata (tested as Selenastrum capricornutum), the 72-h NOEC for growth rate is 1.0 mg/l from a GLP compliant OECD guideline study (Solvay, 2008b).

Long-term ecotoxicity tests with fish and invertebrates are not available.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Test material

Reference

Name:

Unnamed

Type:

impurity

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): Cryolite
- Substance type: slighty coloured powder
- Analytical purity: 96.9%
- Composition of test material, percentage of components: Na 31%, Al 12.6%, F 53.3%
- Storage condition of test material: room temperature

Specific details on test material used for the study:

Name of test material: Cryolite
- Supplier: Solvay Fluor
- Substance type: slightly coloured powder
- Analytical purity: 96.9%
- Composition of test material, percentage of components: Na 31%, Al 12.6% and F 53.5%
- Storage condition of test material: room temperature

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

On day 0 samples were taken in duplicate from all bulk solutions. On day 3 samples were taken from all test solutions. The samples (day 3) were left for one hour to settle down the algae. The test solutions with concentrations of 5, 11 and 25 mg/l were diluted 2, 5 and 10 times respectively with algal medium before analysis.

Test solutions

Vehicle:

no

Details on test solutions:

Four days before test initiation a stock solution of 100 mg/l cryolite was prepared in algal medium by dissolving 50.5 mg in 500 ml algal medium. This stock solution was continuously stirred at 20°C. On the day of test initiation the solution was filtered with filter paper (S&S 595 1/2) to remove undissolved particles.

Test organisms

Test organisms (species):

Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)

Details on test organisms:

Organism: Selenastrum capricornutum (strain ATCC 22662)
Source: Culture Collection of Algae and Protoza, Ambleside, Cumbria, UK
Culturing: Inhouse in 100-ml erlenmeyer flasks with 50 ml filter sterilised medium. Each week a volume of 0.5-2 ml of this culture was transferred into fresh algal medium. The preculture used for this study was transferred into fresh algal medium 4 days prior to the start of the test. The culture chamber is illuminated 24 hours a day with fluorescent lamps.
Initial cell density: 1.0 x 10E4 cells/ml

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test conditions

Hardness:

Not measured

Test temperature:

21 - 23 °C

pH:

7.6 - 7.7

Dissolved oxygen:

not measured

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal: 0, 1.0, 2.2, 5.0, 11 and 25 mg/l
Measured: 0, 1.1, 2.2, 5.1, 11.6 and 25 mg/l

Details on test conditions:

Algae were exposed for three days using 250 ml sterile erlenmeyer flasks containing 100 ml test solution. During the test, the erlenmeyer flasks were placed in a shaking incubator. The shaking speed in the incubator was 90-110 rotations per minute.

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

3.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

8.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

The 72-h EC50 for biomass integral and growth rate were 3.2 and 8.8 mg/l, respectively. The no observed effect concentration (NOEC), based on biomass integral and growth rate at test termination, was 1.0 mg/l. Based on the certificate of analysis cryolite contains 53.3% fluoride. Based on these results, the difference between the nominal and the mean measured concentrations was <20% and for this reason the endpoints of the test were based on nominal concentrations.

Results with reference substance (positive control):

The results of the test revealed a 72-h EC50 of 0.48 mg/l for biomass and 0.85 mg/l for growth rate. The results were in agreement with the results of an interlaboratory test. The EC50 for biomass should be in the range of 0.28 to 1.1 mg/l. The EC50 for growth rate should be in the range of 0.174 to 1.6 mg/l

Reported statistics and error estimates:

Linear interpolation, with concentration on a logarithmic scale, was used tot determine the EC50 values for biomass integral and growth rate inhibition. The NOEC was determined with the Williams test.

Applicant's summary and conclusion

Conclusions:

Because in RAL 3.0 Trisodium hexafluoroaluminate is present in a proportion of less than 1%, the preparation is not harmful to aquatic algae

Executive summary:

One GLP-compliant guideline study (OECD 201) in which the concentrations were analytically verified is available for toxicity in algae. The 72-h EC50 for biomass integral and growth rate were 3.2 and 8.8 mg/L, respectively, in the freshwater species Pseudokirchneriella subcapitata (tested as: Selenastrum capricornutum). The 72-h NOEC, based on biomass integral and growth rate were both 1.0 mg/L (Solvay, 2008b). It was a static test and analytical monitoring has been performed.