RAL 3.0

Toxicity to aquatic plants other than algae

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Administrative data

Endpoint:

toxicity to aquatic plants other than algae

Type of information:

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

Remarks:

Considering that the components with possible negative effects to the aquatic plants are trisodium hexafluoroaluminate and calcium difluoride, namelly fluorides, we will detail their effect, based on published studies.

Adequacy of study:

supporting study

Study period:

2015

Reliability:

2 (reliable with restrictions)

Cross-reference

Reason / purpose for cross-reference:

read-across source

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:

publication

Title:

Unnamed

Year:

2015

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: EPS 1/RM/37 Biological test method: Test for measuring the inhibition of growth using the freshwater macrophyte, Lemna minor

Version / remarks:

2nd eddition (2007) Environment Canada

Deviations:

no

Principles of method if other than guideline:

The purpose of the study was to identify the effect of water hardness and chloride concentration on the LC50 values.

GLP compliance:

not specified

Remarks:

Study is a peer-reviewed published study and GLP is not specified but it is conducted following national guidelines

Sampling and analysis

Details on sampling:

- Sampling method: at beginning and end of the test
- Sample storage conditions before analysis: not specified

Test solutions

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Method: NaF introduced to the test solutions
- Test solutions: 'artificial' test solutions were created with varying hardness (CaCO3) and chloride content

Test organisms

Test organisms (species):

Lemna minor

Details on test organisms:

TEST ORGANISM
- Common name: duckweed
- Source (laboratory, culture collection): in-house culture
- Age of inoculum (at test initiation): two 3-frond plants from a 7-d to 10-d-old culture

Study design

Test type:

static

Water media type:

other: variation of test waters

Limit test:

no

Total exposure duration:

7 d

Test conditions

Hardness:

20 mg/L CaCO3

Test temperature:

25°C

Details on test conditions:

Chloride content 73 mg/L

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

7 d

Dose descriptor:

IC50

Effect conc.:

ca. 1 337 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: dry weight

Effect concentrations 2

Key result

Duration:

7 d

Dose descriptor:

IC50

Effect conc.:

ca. 803.39 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: frond growth

Details on results:

Lemna is relatively insensitive to fluoride

Results with reference substance (positive control):

Acceptable limits for control performance.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Lemna minor was found to be relatviely insensitive to fluoride with an IC50 value (frond number) of 391 mg/L F. This relates to a IC50 of 803 mg CaF2/L and relates to 720 mg Na3AlF6/L.

Executive summary:

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 mg CaF2/L, and relates to 720 mg Na3AlF6/L.