Dienstag, 23. Februar 2016

Short-term toxicity to aquatic invertebrates.001 to 002

Short-term toxicity to aquatic invertebrates. 001


Administrative data

Purpose flag:
supporting study
Study result type:
read-across from supporting substance (structural analogue or surrogate)
Study period:
not specified
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
Study well conducted with standard guidelines and chemical analysis. No GLP no analytical certificates and no raw data.

Data source

Reference
Reference Type:
publication
Title:
Effects of hardness, chloride, and acclimation on the acute toxicity of sulfate to freshwater invertebrates.
Author:
Soucek, D.J. and Kennedy, A.J.
Year:
2005
Bibliographic source:
Environmental Toxicology and Chemistry, Vol. 24, No. 5, pp. 1204-1210

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other guideline: American Society for Testing and Materials E729-96 methods
GLP compliance:
no data

Test materials

Identity of test material same as for substance defined in section 1 (if not read-across):
no
Test material identityopen allclose all
Identifier:
EC name
Identity:
sodium sulphate
Details on test material:
Anhydrous sodium sulfate
purity: 99%
Fisher Scientific
Analytical monitoring:
yes
Details on sampling:
No details given
Vehicle:
no
Details on test solutions:
No details given.
The results are based on measured concentrations.

Test organisms

Test organisms (species):
Ceriodaphnia dubia
Details on test organisms:
TEST ORGANISM
- Source: in-house culture according to US EPA methods.
- Age at study initiation: less than 24h

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
48 h

Test conditions

Hardness:
MHRW: 94 mg CaCO3/l,
Ca/Mg (molar ratio) = 0.88
RMHRW: 107 mg CaCO3/l
Ca/Mg (molar ratio) = 3.25

Several hardness levels were tested with MHRW, namely 200, 300, 400, 500 and 600 mg CaCO3/l.
Test temperature:
25 °C
pH:
7.9
Nominal and measured concentrations:
No details given.
The results are based on measured concentrations.
Details on test conditions:
TEST SYSTEM
- Test container (material, size): 50 ml glass beakers


EXPOSURE REGIME
- No. of organisms per container (treatment): 5
- No. of replicates per treatment group: No data
- No. of replicates per control / vehicle control: No data
Three assays were conducted to increase confidence in LC50-values.
- Feeding regime: No feeding


TEST MEDIUM / WATER PARAMETERS
- Type of water: Moderately Hard Reconstituted Water (MHRW) and Reformulated Moderately Hard Reconstituted Water (RMHRW)
MHRW
- Conductivity: 295 S/cm
- K+: 2.1 mg/l
- Na+: 26.3 mg/l
- Ca2+: 17.6 mg/l
- Mg2+: 12.1 mg/l
- SO4 2-: 90.2 mg/l
- Cl-: 1.9 mg/l
- HCO3 -: 69.7 mg/l

RMHRW
- Conductivity: 341 S/cm
- K+: 2.1 mg/l
- Na+: 26.3 mg/l
- Ca2+: 32.7 mg/l
- Mg2+: 6.1 mg/l
- SO4 2-: 59.2 mg/l
- Cl-: 33.9 mg/l
- HCO3 -: 69.7 mg/l


OTHER TEST CONDITIONS
- Photoperiod: 16h


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Survival, every 24h
Reference substance (positive control):
yes
Remarks:
Sodium chloride

Results and discussion

Effect concentrationsopen allclose all
Duration:
48 h
Endpoint:
LC50
Effect conc.:
3 031 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks (e.g. 95% CL):
Test medium is MHRW
Duration:
48 h
Endpoint:
LC10
Effect conc.:
2 601 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks (e.g. 95% CL):
Test medium is MHRW.
Duration:
48 h
Endpoint:
LC50
Effect conc.:
3 735 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks (e.g. 95% CL):
Test medium is RMHRW.
Duration:
48 h
Endpoint:
LC50
Effect conc.:
4 436 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks (e.g. 95% CL):
Test medium is MRHW with 200 mg CaCO3/l.
Duration:
48 h
Endpoint:
LC50
Effect conc.:
4 356 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks (e.g. 95% CL):
Test medium is MHRW with 300 mg CaCO3/l.
Duration:
48 h
Endpoint:
LC50
Effect conc.:
4 693 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks (e.g. 95% CL):
Test medium is MHRW with 400 mg CaCO3/l.
Duration:
48 h
Endpoint:
LC50
Effect conc.:
5 199 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks (e.g. 95% CL):
Test medium is MHRW with 500 mg CaCO3/l.
Duration:
48 h
Endpoint:
LC50
Effect conc.:
4 862 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
test mat.
Basis for effect:
mortality
Remarks (e.g. 95% CL):
Test medium is MHRW with 600 mg CaCO3/l.
Details on results:
All measured concentrations of sodium sulfate were close to nominal except for the concentration measured in MHRW with 600 mg CaCO3. This concentration was somewhat lower than nominal, suggesting that pressipitation of Calcium sulfate occurred. Therefore results may be questionable at this hardness level.
Results with reference substance:
Mean LC50 is 2030 mg/l, which was comparable to the value of 1960 mg/l reported by Mount et al., 1997.
Reported statistics and error estimates:
LC50 values were calculated using the Spearman-Karber method.
To provide a stronger estimate of the LC50 values geometric means were calculated from the three assays.
Any other information on results incl. tables:
The results in the publication are given as mg sulfate ion, these values were converted to mg sodium sulfate.
MHRW: Moderately Hard Reconstituted Water
RMHRW: Reformulated Moderately Hard Reconstituted Water

Applicant's summary and conclusion

Conclusions:
Sodium sulfate is not toxic to C. dubia, the lowest LC50 found for MHRW is 3031 mg/l.
The test was found to be valid with restrictions because the study was well conducted with standard guidelines and chemical analysis. No GLP no analytical certificates and no raw data were documented.
Executive summary:
The test was performed according to American Society for Testing and Materials E729-96 methods. Ceriodaphnia dubia was exposed to sodium sulfate for 48h in two different test media, namely Moderately Hard Reconstituted Water (MHRW) and Reformulated Moderately Hard Reconstituted Water (RMHRW) and several water hardness levels.
Sodium sulfate is not toxic to C. dubia, the lowest LC50 found for MHRW is 3031 mg/l.
When water hardness increased, toxicity of sodium sulfate decreased.
Validity criteria fulfilled:
no data

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