Sodium sulphate

Short-term toxicity to fish

Administrative data

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Literature data

Data source

Reference

Reference Type:

publication

Title:

Statistical models to predict the toxicity of major ions to Ceriodaphnia Dubia, Daphnia Magna and Pimephales Promelas (fathead minnows)

Author:

Mount David R., Gulley David D., Hockett Russel J., Garrison Tyler D., Evans James M.

Year:

1997

Bibliographic source:

Environmental Toxicology and Chemistry, Vol. 16, No. 10, pp. 2009–2019, 1997

Materials and methods

Principles of method if other than guideline:

96 hours test, based on EPA/600/4-90/ 027 (1991) guideline.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Sodium sulphate

EC Number:

231-820-9

EC Name:

Sodium sulphate

Cas Number:

7757-82-6

Molecular formula:

H2O4S.2Na

IUPAC Name:

disodium sulfate

Test solutions

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION
- Test solutions: were prepared by dissolving individual ion salts in moderately hard reconstituted water (MHRW)
- Stock solution: were prepared from the salt by dissolving 10000 mg/L in MHRW.
- Differential loading: test solutions were prepared by serially diluting the 10000-mg/L stock solutions with MHRW to develop a series of test concentrations spaced on a 0.5 x dilution factor (i.e., 10000, 5000, 2500, 1250 mg/L).

Test organisms

Test organisms (species):

Pimephales promelas

Details on test organisms:

TEST ORGANISM
- Common name: Fathead minnow
- Age at study initiation: 1 to 7 days old
- Source: all organisms used were obtained from in-house cultures (ENSR, Fort Collins, CO, USA)

CULTURE
- Medium: tap water pretreated with activated carbon.
- Temperature: at 20 to 25°C

Study design

Test type:

static

Water media type:

freshwater

Total exposure duration:

96 h

Test conditions

Test temperature:

25°C

pH:

Between pH 7.5 and 9.0

Dissolved oxygen:

> 40% saturation

Nominal and measured concentrations:

10000, 5000, 2500, 1250 mg/L ion concentrations measured in the stock solutions; they are compared to nominal values.

Details on test conditions:

PRE-TEST FOR FEEDING EVALUATION
To assess the potential effect of feeding on major ion toxicity, initial tests using C. dubia were conducted both with and without feeding. Analysis of these initial experiments showed that the addition of food represented only a small influence on C. dubia survival.

TEST SYSTEM
- Test vessel: 30-ml plastic beakers containing 10 ml of test solution
- No. of organisms per vessel: 5 organisms per chamber
- Feeding during the test: because the effect of feeding was small and its inclusion was believed to provide a more representative test matrix, remaining C. dubia tests included feeding, as did all fathead minnow. 100 µl of concentrated brine shrimp nauplii was added after 48 h of exposure, though solutions were not subsequently renewed as recommended by the USEPA

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: moderately hard reconstituted water (MHRW)
Concentrations of major ions were determined analytically in all stock solutions used in testing. Ca2+, Na+, Mg2+ and K+ were determined using inductively coupled plasma emission spectroscopy (ICP) according to USEPA method 200.7; chloride and sulphate concentrations were determined by anion chromatography; and HCO3- concentrations were determined indirectly by the measurement of phenolphthalein alkalinity. As HCO3- is the predominate carbonate species present in the pH range of interest (pH 6.5-9.0), alkalinity equivalents were converted directly to HCO3- concentration.
Dissolved oxygen (DO) and pH were measured in selected test solutions during actual toxicity testing, primarily on solutions near the threshold for acute toxicity. DO was measured with a Yellow Springs Instrument model 54 DO meter (Yellow Springs, OH, USA) while pH was measured with a Orion pH meter model SA250 (Boston, MA, USA).

OTHER TEST CONDITIONS
- Photoperiod: 16-h : 8-h light : dark

OBSERVATION
Daily observations of mortality. The criteria for death were no visible movement and no response to prodding

Reference substance (positive control):

yes

Remarks:

NaCl

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

ca. 7 960 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 2

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

> 7 960 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Effect concentrations 3

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

> 8 080 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

mortality (fish)

Applicant's summary and conclusion

Conclusions:

Pimephales promelas LC50 96h = 7960 mg/L

Executive summary:

A 96 hours test, based on EPA/600/4-90/ 027 (1991) guideline was conducted to evaluate the short term toxicity of sodium sulphate on fish, Pimephales promelas.

Result

Pimephales promelas LC50 96h = 7960 mg/L