dipotassium octaborate

Long-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

long-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions. Peer reviewed technical publication. Well done study and report that meets basic scientific principles.

Data source

Reference

Reference Type:

publication

Title:

Sensitivity of four New Zealand cladoceran species and Daphnia magna to aquatic toxicants

Author:

Hickey, CW

Year:

1989

Bibliographic source:

New Zealand Journal of Marine and Freshwater Research, Vol. 23: 131-137

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: US EPA 1982 EG-2

Principles of method if other than guideline:

10 individual neonates were each placed in 15 ml of test solution in polystyrene beakers for 14 days.

GLP compliance:

not specified

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

Details on test material:

Boron (H3BO3, AR grade)

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Source: A stock culture of Daphnia magna was obtained from Mrs D.M.M. Adema, Division of Technology for Society (TNO) Delft, The Netherlands
- Method of breeding: bred in 8 litres of medium composed of equal volumes of upper Waihou River water and standard dilution water (British Standard 1983) in glass tanks at 20 +-2°C. Organisms were fed on alternate days with 2 ml of nutrient solution (0.75g beef extract and 0.75g glucose per 100 ml stored at 4°C), and daily with the alga Selenastrum capricornutum.
- Feeding during test
- Food type: digested trout pellet-yeast
- Amount: at a rate of 0.15 ml of food suspension per 40 ml of test solution
- Frequency: daily
- test organisms were < 24 h old for testing

Study design

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

14 d

Test conditions

Hardness:

250 +- 25 g/m³

Test temperature:

20 +- 1 °C

pH:

7.9 +- 0.2

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 40 ml of test solution in polystyrene beakers
- Renewal rate of test solution (frequency/flow rate): organisms were transferred to a fresh test solution every 48h
- No. of organisms per vessel: 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Standard dilution water (HMSO 1983; British Standard 1983) was prepared in ultrapure water (Nanopure System, Barnstead) which had been stored for at least 1 week in glass carboys.
- Ca/Mg ratio: 4 : 1

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

18 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

reproduction

Effect concentrations 2

Duration:

14 d

Dose descriptor:

LOEC

Effect conc.:

32 mg/L

Nominal / measured:

nominal

Conc. based on:

element

Basis for effect:

reproduction

Reported statistics and error estimates:

An analysis of variance (ANOVA) with Tukey's significance tests (one-tailed, P = 0.05) was used to compare each toxicant concentration mean with the control mean to determine the NOEC, and the LOEC.