Potassium metaborate

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Remarks:

reported in a publication

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

review article

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Remarks:

reported in a publication

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

review article

Justification for type of information:

REPORTING FORMAT FOR THE ANALOGUE APPROACH
see target record

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

read-across source

Remarks:

target record

Qualifier:

no guideline required

Principles of method if other than guideline:

Review of literature data

GLP compliance:

no

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Daphnia magna Straus

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Hardness:

150 resp. 166 mg/L

Test temperature:

20 resp. 19.2 °C

pH:

6.7 - 8.1 resp. 7.1 - 8.7

Details on test conditions:

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Lake Huron water resp. Carbon-filtered well water

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

133 mg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

boron

Basis for effect:

not specified

Remarks on result:

other: corresponding to 1007.7 mg/L BHO2.K

Remarks:

Lake Huron water, 20°C, pH 6.7 - 8.1, Hardness 150 mg/l

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

226 mg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

boron

Basis for effect:

not specified

Remarks on result:

other: corresponding to 1712.3 mg/L BHO2.K

Remarks:

Carbon-filtered well water, 19.2°C, pH 7.1 - 8.7, hardness 166 mg/L

Validity criteria fulfilled:

not specified

Conclusions:

The present information was based on a literature review of various suitable read-across substances all belonging to the group of borates, the relevant information on short term toxicity in daphnia magna was taken from boric acid. The lowest available LC50 value was 133 mg/L, which corresponds to 1007 mg/l BHO2.K. So the available data shows that neither boron nor potassium metaborate needs to be classified as aquatic toxic acc. Regulation 1272/2008, as all LC50 values were above the limit value for classification of 100 mg/l.

Executive summary:

A literature review of showed that boron / potassium metaborate gave consistently LC50 values > 100 mg/l.

Cross-reference 2

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Remarks:

reported in a publication

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline required

Principles of method if other than guideline:

Review of literature data

GLP compliance:

no

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

other: Mosquito fish and Coho salmon, among others

Details on test organisms:

Mosquito fish (Gambusia affinis), adult females
Coho salmon (0. kisutch), under yearlings, 1.8-3.8 g

Test type:

other: static & static renewal

Water media type:

other: freshwater and seawater

Total exposure duration:

96 h

Test temperature:

20-23°C or 22-26°C or 8°C

pH:

5.4-7.3 or 8.6-9.1 (freshwater fish)

Salinity:

28 promiile (seawater fish)

Reference substance (positive control):

not required

Duration:

96 h

Dose descriptor:

LC50

Remarks:

Mosquito fish, boric acid (TLm)

Effect conc.:

978 mg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

boron

Basis for effect:

mortality (fish)

Remarks on result:

other: corresponding to 7409.7 mg/L BHO2.K

Remarks:

20-23°C; pH 5.4-7.3; turbidity 210-250 mg / liter, static

Duration:

96 h

Dose descriptor:

LC50

Remarks:

Mosquito fish, sodium tetraborate (TLm)

Effect conc.:

408 mg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

boron

Basis for effect:

mortality (fish)

Remarks on result:

other: corresponding to 3091.2 mg/L BHO2.K

Remarks:

22-26°C; pH 8.6-9.1; turbidity 410-650 mg / liter, static

Duration:

96 h

Dose descriptor:

LC50

Remarks:

Coho Salmon, sodium metaborate

Effect conc.:

40 mg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

boron

Basis for effect:

mortality (fish)

Remarks on result:

other: corresponding to 303.1 mg/L BHO2.K

Remarks:

Seawater; 8°C; salinity 28 promille, static renewal (daily)

Validity criteria fulfilled:

not specified

Conclusions:

The present information was based on a literature review of various suitable read-across substances all belonging to the group of borates. The lowest available LC50 value was 40 mg/L in an seawater organism, which corresponds to 303 mg/l BHO2.K, the other values were a magnitude higher. So the available data shows that potassium metaborate does not need to be classified as aquatic toxic acc. Regulation 1272/2008, as all LC50 values for potassium metaborate were calculated to be above the limit value for classification of 100 mg/l.

Executive summary:

A literature review of showed that potassium metaborate gave consistently LC50 values > 100 mg/l.

Data source

Reference

Reference Type:

review article or handbook

Title:

Safety Assessment of Boron in Aquatic and Terrestrial Environments

Author:

Butterwick L, De Oude N, Raymond K

Year:

1989

Bibliographic source:

ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 17, 339-371 (1989)

Materials and methods

Test guideline

Qualifier:

no guideline required

Principles of method if other than guideline:

Review of literature data

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Boric acid

EC Number:

233-139-2

EC Name:

Boric acid

Cas Number:

10043-35-3

Molecular formula:

H3BO3

IUPAC Name:

Boric acid

Test material form:

solid: particulate/powder

Details on test material:

White odourless crystalline powder
Melting point: 168 - 171 °C
Water solubility: 49.5 g/l
pH-value: 3.8 - 4.8
Decomposition temperature: ca. 100 - 130 °C
Formation of metaboric acid by loss of water. At 160 deg C a glassy melt of boron trioxide is formed by further loss of water.
LD50 oral rat: 2660 mg/kg

Sampling and analysis

Analytical monitoring:

not specified

Test solutions

Vehicle:

not specified

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Water flea
- Strain/clone: Daphnia magna Straus

Study design

Test type:

semi-static

Water media type:

freshwater

Total exposure duration:

21 d

Test conditions

Hardness:

150 resp. 166 mg/L

Test temperature:

20 resp. 19.2 °C

pH:

6.7 - 8.1 resp. 7.1 - 8.7

Details on test conditions:

TEST SYSTEM
- Renewal rate of test solution (frequency/flow rate): 3 times weekly

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Lake Huron water resp. Carbon-filtered well water

Reference substance (positive control):

not specified

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

52.2 mg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

boron

Basis for effect:

not specified

Remarks on result:

other: corresponding to 395.5 mg/L BHO2.K

Remarks:

Lake Huron water, 20°C, pH 6.7 - 8.1, Hardness 150 mg/l

Effect concentrations 2

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

6.4 mg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

boron

Basis for effect:

not specified

Remarks on result:

other: corresponding to 48.5 mg/L BHO2.K

Remarks:

Lake Huron water, 20°C, pH 6.7 - 8.1, Hardness 150 mg/l

Effect concentrations 3

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

13.6 mg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

boron

Basis for effect:

not specified

Remarks on result:

other: corresponding to 103 mg/L BHO2.K

Remarks:

Lake Huron water, 20°C, pH 6.7 - 8.1, Hardness 150 mg/l

Effect concentrations 4

Duration:

21 d

Dose descriptor:

LC50

Effect conc.:

53.2 mg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

boron

Basis for effect:

not specified

Remarks on result:

other: corresponding to 403.1 mg/L BHO2.K

Remarks:

Carbon-filtered well water, 19.2°C, pH 7.1 - 8.7, hardness 166 mg/L

Effect concentrations 5

Key result

Duration:

21 d

Dose descriptor:

NOEC

Effect conc.:

6 mg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

boron

Basis for effect:

not specified

Remarks on result:

other: corresponding to 45.5 mg/L BHO2.K

Remarks:

Carbon-filtered well water, 19.2°C, pH 7.1 - 8.7, hardness 166 mg/L / lowest available value

Effect concentrations 6

Key result

Duration:

21 d

Dose descriptor:

LOEC

Effect conc.:

13 mg/L

Nominal / measured:

not specified

Conc. based on:

element

Remarks:

boron

Basis for effect:

not specified

Remarks on result:

other: corresponding to 98.5 mg/L BHO2.K

Remarks:

Carbon-filtered well water, 19.2°C, pH 7.1 - 8.7, hardness 166 mg/L

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

The present information was based on a literature review of various suitable read-across substances all belonging to the group of borates, the relevant information on short term toxicity in daphnia magna was taken from boric acid. The lowest available chronic NOEC was 6 mg/L, which corresponds to 45.5 mg/l BHO2.K. So the available data shows that neither boron nor potassium metaborate needs to be classified as chronic aquatic toxic acc. Regulation 1272/2008, as all NOECs were above the limit value for classification of 1 mg/l for Non-rapidly degradable substances for which there are adequate chronic toxicity data available.

Executive summary:

A literature review of showed that boron / potassium metaborate gave consistently NOECs > 1 mg/l.