Potassium bromate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Apr 27- Apr 29, 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

The study was performed in compliance with the Good Laboratory Practice (GLP) regulations (revised in 1997, ENV/MC/CHEM(98)17). The method followed that described in the OECD Guidelines for Testing of Chemicals (Adopted: 4 April 1984) No 202 "Daphnia sp., Acute Immobilisation Test. and Reproduction Test".

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

Principles of method if other than guideline:

None

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Potassium bromate

EC Number:

231-829-8

EC Name:

Potassium bromate

Cas Number:

7758-01-2

Molecular formula:

BrHO3.K

IUPAC Name:

potassium bromate

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

Samples were taken from all concentrations at the beginning of the study and after 48 hours. After preparation of the test media the analytical values were determined.

Test solutions

Vehicle:

no

Details on test solutions:

Reconstituted water according to ELENDT (1990):
Macro nutrients (mg/L):
CaCI2 x 7 H20 293.80
MgSO4 x 7 H20 123.30
NaHCO3 64.80
KCI 5.80
Na2SiO3 x 9H20 10.00
NaNO3 0.27
KH2PO4 0.14
K2HPO4 0.18

Trace elements (mg/L):
B 0.5000
Fe 0.2000
Mn 0.1000
Li, Rb and Sr 0.0500
Mo 0.0250
Br 0.0125
Cu and Zn 0.0063
Co and I 0.0025
Se 0.0010
V 0.0003

Macro nutrients (mg/L):
Na2EDTA x 2H20 2.50

Vitamins (µg/L):
Thiamine 75.00
B12 1.00
Biotin 0.75


After preparation, the reconstituded water was aerated for 24 hours.

- Hardness: about 14° dH (about 250 mg/L CaCO3)
- pH: 7.9 ± 0.3, after an aeration for 24 hours.



References:

ELENDT, B.-P. Selenium deficiency in Crustacea. An ultrastructural approach to antennal damage in Daphnia magna Straus.
Protoplasma 154, 25-33, 1990

Test organisms

Test organisms (species):

Daphnia magna

Details on test organisms:

Species: Daphnia magna Straus
Breeder: in house
Age: not older than 24 hours
This species is internationally accepted for this type of study.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

48 h

Test conditions

Hardness:

14 ° dH (about 250 mg/L CaCO3)

Test temperature:

21 – 22°C

pH:

7.9 +/- 0.3

Dissolved oxygen:

at least 90 %

Nominal and measured concentrations:

100.0 mg/L (nominal) = 99.5 mg/L (measured)

Details on test conditions:

for details see executive summary

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Effect concentrations 2

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Details on results:

for details see executive summary

Results with reference substance (positive control):

for details see executive summary

Reported statistics and error estimates:

for details see executive summary

Any other information on results incl. tables

for details see executive summary

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the given experimental conditions, the test material showed a 24 h and 48 h EC50 value > 100 mg/L nominally.
An aqueous solution of nominal 100 mg/L of potassium bromate revealed no aquatic toxicity in the test system.

Executive summary:

Purpose
The purpose of this assay was to identify the aquatic toxicity potential of potassium bromate in Daphnia magna to provide a rational basis for hazard estimation for the test item in aquatic environments

Study Design
For this purpose, juvenile daphnids were exposed to an aqueous test material solution over 48 hours, under defined conditions. The study comprised of four test vessels per concentration and control group containing five daphnids each, i.e. 20 daphnids per concentration (test medium group) and control group.
Daphnids were exposed to a nominal test material concentration of 100 mg/L (limit test) in an open static system.


Results
The limit of quantification of the analytical method was 0.07 mg/L. The analytical recovery was 100 and 99 % after 0 and 48 hours, respectively. The mean recovery over 48 hours was 99.5 %. During the experimental phase of the study, the test material concentration could be maintained at ≥ 80 % of the initial concentration. The test was performed as a static test in open vessels.
As the stability of the test material in the aqueous solution was ≥ 80 % of the nominal concentration, the EC50 values were calculated with the nominal concentrations. Nominal, corresponding mean analytical concentrations, and number of immobilized daphnids are given in the following table.

Nominal concentration	Mean analytical concentration during the study		Immobilized/exposed daphnids
[mg/L]	[%]	[mg/L]	24 hours	48 hours
0	-	-	0/20	0/20
100	99.5	99.5	0/20	1/20

Immobilization was observed in one daphnia exposed to 100 mg/L after 48 hours.
For the test material, the following nominal EC50 values for daphnids were determined:
24 h EC50     > 100 mg/L
48 h EC50     > 100 mg/L


Conclusion
Under the given experimental conditions, the test material showed a 24 h and 48 h EC50  value > 100 mg/L nominally.
An aqueous solution of nominal 100 mg/L of potassium bromate revealed no aquatic toxicity in the test system.