Potassium pentaborate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Guideline study; well performed study

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

other: ASTM E729-95 Standard Guide for Conducting Acute Toxicity Tests on Test Materials with Fishes, Macroinvertebrates, and Amphibians

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 850.1075 (Freshwater and Saltwater Fish Acute Toxicity Test)

GLP compliance:

no

Remarks:

study is not in compliance with GLP

Analytical monitoring:

yes

Details on sampling:

A sample of each treatment was taken at the beginning and end of the test.

Vehicle:

no

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: Fathead minnow
- Source: Aquatic Biosystems, Fort Collins Colorado
- Age at study initiation (mean and range, SD): less than 7 d

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Hardness:

91

Test temperature:

24.7 °C

pH:

8.0

Dissolved oxygen:

> 6.0 mg/L

Nominal and measured concentrations:

Nominal: Control, 15.6, 31.3, 62.5, 125, 250 mg B/L
Measured: <0.022, 15, 32, 64, 125, 255 mg B/L

Details on test conditions:

TEST SYSTEM
- Test vessel: 250 ml beakers
- Type : open
- Material, size, headspace, fill volume: glass, 200 ml
- Aeration: none
- Renewal rate of test solution: none

- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates):4
- No. of vessels per control (replicates): 4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: MHRW (moderately hard reconstituted water) per US EPA 2002
- Total organic carbon: 0 nominal
- Chlorine: 0 nominal
- Ca/mg ratio: 1.46
- Culture medium different from test medium: Yes. Test organisms were cultured at Aquatic Biosystems Lab water, hardness 114 mg/L, alkalinity 115 mg/L
- Intervals of water quality measurement: boron, pH, conductivity, alkalinity, hardness at beginning and end of test, temperature and dissolved oxygen daily

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Photoperiod: 16 h light : 8 h dark

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

79.7 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

element

Basis for effect:

mortality (fish)

Remarks on result:

other: (95% CI 72-88 mg B/L), control mortality 2.5%

Sublethal observations / clinical signs:

Biological results:

Measured Concentration (mg B/L)	Number dead (out of 40)	Mortality [%]
<0.022 (control)	1	2.5
15	3 of 39	7.7
32	0	0.0
64	8	20.0
125	38	95.0
255	40	100.0

Validity criteria fulfilled:

not specified

Conclusions:

The study was conducted according to ASTM E729-95 and EPA OPPTS 850.1075 on the registered substance itself. The method is to be considered scientifically reasonable and the results can be considered as reliable to assess the toxicity of boric acid towards freshwater fish.
The toxic effect of the test item boric acid was assessed on the freshwater species Fathead minnow (Pimephales promelas) in a static 96 h concentration-response test. The 96-hour LC50 was determined to be 79.7 mg B/L. The exposure concentrations were verified by analytical measurements for each treatment at the start and the end of the test. Reported results refer to geometric mean measured concentrations.

Executive summary:

The study was conducted according to ASTM E729-95 and EPA OPPTS 850.1075 on the registered substance itself.

The purpose of this study was to determine the toxicity of the test item to fish. For this purpose, the freshwater species Fathead minnow (Pimephales promelas) was exposed in a static test to various concentrations under defined conditions for 96 hours. The study encompassed 6 treatment groups (5 dose rates of the test item and a control) each containing 40 individuals. The exposure concentrations were verified by analytical measurements. The mortality of the fish was determined by visual observation after 24, 48, 72 and 96 hours.

The 96h-LC50 was determined to be 79.7 mg B/L based on geometric mean measured concentrations.

Reference 2

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Peer reviewed study

Qualifier:

no guideline followed

Principles of method if other than guideline:

The acute toxicity of boron has been studied with the dab (Limanda limanda) by subjecting them to a range of concentrations of the test material for 96 h in a continuous flow system. No standard guideline was identified, but methods were equivalent to standard fish toxicity testing methods.

GLP compliance:

yes

Remarks:

OECD, 1982

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Limanda limanda

Details on test organisms:

TEST ORGANISM
- Common name: Dab
- Source: Uncontaminated south Devon environments
- Age at study initiation (mean and range, SD):
- Length at study initiation (length definition, mean, range and SD): mean length of 10.1 cm (range 7.0 - 13.2 cm)
- Weight at study initiation (mean and range, SD): mean weight of 16.9 g (range 5.6 - 30.8 g)
- Feeding during test: No feeding during test


ACCLIMATION
- Acclimation period: > 7 days in the laboratory, then acclimated to the test temperature of 12°C at a rate of 1-3 °C per day from their ambient temperature storage conditions. They were then maintained at the test temperature for a minimum of three days before being transferred to the test system where they were held for a minimum of 24 h under test conditions prior to the commencement of the exposure to the test substance.
- Feeding frequency: No feeding during acclimatisation

Test type:

flow-through

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

12 +-1 °C

pH:

7.7 +/- 0.8

Dissolved oxygen:

7.9 +/- 0.6 mg/L

Salinity:

34.6 +/- 0.2 ‰

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 30 L rectangular glass tanks
- Aeration: The test solutions were gently aerated with compressed air.
- Renewal rate of test solution (frequency/flow rate): 24h
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1


TEST MEDIUM / WATER PARAMETERS
- Intervals of water quality measurement: 24h

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

74 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

element

Basis for effect:

mortality (fish)

Remarks on result:

other: 66.4-83.0 mg/L

Reported statistics and error estimates:

Probit analysis (Finney, 1971), of mortality observations every 24 h and measured test substance concentration gave the LC50 values for each substance.

Sublethal observations / clinical signs:

LC50 after 24h : 88.3 (80.3 - 97.3) mg/L

LC50 after 48h : 75.7 (68.0 - 85.0) mg/L

LC50 after 72h : 75.7 (68.0 - 85.0) mg/L

Conclusions:

The study was not conducted according to standard guidelines, but methods are equivalent to standard fish toxicity testing methods. Hence, the method is to be considered scientifically reasonable and the results can be considered as reliable to assess the toxicity towards fish. The test was conducted on the test material Disodium tetraborate.
The toxic effect towards fish was assessed on the saltwater species Dab (Limanda limanda) in a 96 h concentration-response test with flow-through conditions. The 96-hour LC50 was determined to be 74 mg/L based on the boron element. The exposure concentrations were verified by analytical measurements.

Executive summary:

The study was not conducted according to standard guidelines, but methods are equivalent to standard fish toxicity testing methods. The test was conducted on the test material Disodium tetraborate.

The purpose of this study was to determine the toxicity of the test item to fish. For this purpose, the saltwater species Dab (Limanda limanda) was exposed in a static test to various concentrations under defined conditions for 96 hours. The study encompassed 6 treatment groups (5 dose rates of the test item and a control) each containing 20 individuals.The exposure concentrations were verified by analytical measurements. The mortality of the fish was determined by visual observation after 24, 48, 72 and 96 hours.

The 96h-LC50 was determined to be 74 mg/L based on the boron element.

Description of key information

Only 1 short-term toxicity value for freshwater fish has been selected, i.e. for the fathead minnow P. promelas with a 4 days LC50 of 79.7 mg B/L. 
Only 1 short-term toxicity value for marine fish has been selected, i.e. for the dab L. limanda with a 4 days LC50 of 74.0 mg B/L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

79.7 mg/L

Marine water fish

Marine water fish

Effect concentration:

74 mg/L

Additional information

The study (Taylor, 1985) was not conducted according to standard guidelines, but methods are equivalent to standard fish toxicity testing methods. The test was conducted on the test material disodium tetraborate.

The toxic effect towards fish was assessed on the saltwater species dab (Limanda limanda) in a 96 h concentration-response test with flow-through conditions. The study encompassed 6 treatment groups (5 concentration rates of the test item and a control) each containing 20 individuals. The exposure concentrations were verified by analytical measurements. The mortality of the fish was determined by visual observation after 24, 48, 72 and 96 hours.

The 96h-LC50 was determined to be 74 mg/L based on the boron element.

 

The other study (Soucek et al, 2010) was conducted according to ASTM E729-95 and EPA OPPTS 850.1075 on the registered substance itself.

The toxic effect of the test item boric acid was assessed on the freshwater species fathead minnow (Pimephales promelas) in a static 96 h concentration-response test under defined conditions. The study encompassed 6 treatment groups (5 dose rates of the test item and a control) each containing 40 individuals. The exposure concentrations were verified by analytical measurements. The mortality of the fish was determined by visual observation after 24, 48, 72 and 96 hours.

The 96h-LC50 was determined to be 79.7 mg B/L based on geometric mean measured concentrations.

 

Please also refer to read-across statement in section 13.