Potassium tetrahydroborate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Materials and methods are described in detail. Peer-reviewed publication that meets basic scientific principles.

Qualifier:

according to guideline

Guideline:

other: ASTM Standard E 729-80

Principles of method if other than guideline:

Materials and methods are described in detail. Peer-reviewed publication that meets basic scientific principles.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

Source: Brood stock
Age at study initiation: < 24h

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

148 +- 7 mg/L as CaCO3

Test temperature:

20.1 - 20.7 °C

pH:

6.7 - 8.1

Dissolved oxygen:

> 60% saturation

Conductivity:

290 +- 21 µmhos/cm

Nominal and measured concentrations:

The nominal concentrations were : 54, 91, 151, 252, 420 and 700 mg/l as boron

Details on test conditions:

Source/preparation of dilution water: Lake Huron water was used to culture daphnids and as the test dilution water. This water was carbon-filtered, UV-irradiated and adjusted to a hardness of approximately 170 mg/L as (CaCO3) with CaCl2. The water was then autoclaved at 120°C and 124.1 kPa for 35 min.
Photoperiod: 16h light : 8 h dark

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

133 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

based on boron

Basis for effect:

mortality

Remarks on result:

other: 95 % confidence intervals: 115 - 153 mg/L as boron

Key result

Duration:

48 h

Dose descriptor:

LC0

Effect conc.:

< 54 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

based on boron

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

LC100

Effect conc.:

420 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

based on boron

Basis for effect:

mortality

Conclusions:

The calculated 48-h static acute LC50 value of boric acid was 133 mg/L as boron (95% confidence interval 115-153 mg/L) (probit), The no-kill level for this test was less than 54 mg/L and the 100% kill concentration was 420 mg/L.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Under standard ecological conditions, potassium tetrahydroborate decomposes to boric acid and borate salts, respectively. Thus the aquatic toxicity of boric acid should be determined to evaluate the toxicity of potassium tetrahydroborate.

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: ASTM Standard E 729-80

Principles of method if other than guideline:

Materials and methods are described in detail. Peer-reviewed publication that meets basic scientific principles.

GLP compliance:

no

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Daphnia magna

Details on test organisms:

Source: Brood stock
Age at study initiation: < 24h

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Hardness:

148 +- 7 mg/L as CaCO3

Test temperature:

20.1 - 20.7 °C

pH:

6.7 - 8.1

Dissolved oxygen:

> 60% saturation

Conductivity:

290 +- 21 µmhos/cm

Nominal and measured concentrations:

The nominal concentrations were : 54, 91, 151, 252, 420 and 700 mg/l as boron

Details on test conditions:

Source/preparation of dilution water: Lake Huron water was used to culture daphnids and as the test dilution water. This water was carbon-filtered, UV-irradiated and adjusted to a hardness of approximately 170 mg/L as (CaCO3) with CaCl2. The water was then autoclaved at 120°C and 124.1 kPa for 35 min.
Photoperiod: 16h light : 8 h dark

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

133 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

based on boron

Basis for effect:

mortality

Remarks on result:

other: 95 % confidence intervals: 115 - 153 mg/L as boron

Key result

Duration:

48 h

Dose descriptor:

LC0

Effect conc.:

< 54 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

based on boron

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

LC100

Effect conc.:

420 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Remarks:

based on boron

Basis for effect:

mortality

Conclusions:

The calculated 48-h static acute LC50 value of boric acid was 133 mg/L as boron (95% confidence interval 115-153 mg/L) (probit), The no-kill level for this test was less than 54 mg/L and the 100% kill concentration was 420 mg/L.
As boric acid is the decompositon product of potassium tetrahydroborate, the same values can be stated for potassium tetrahydroborate.

Description of key information

The calculated 48-h static acute LC50 value of boric acid was 133 mg/L as boron (95% confidence interval 115-153 mg/L) (probit), The no-kill level for this test was less than 54 mg/L and the 100% kill concentration was 420 mg/L.

As boric acid is the decompositon product of potassium tetrahydroborate, the same values can be stated for potassium tetrahydroborate.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

133 mg/L