Short-term toxicity to aquatic invertebrates.012 to 013

Short-term toxicity to aquatic invertebrates.012

Administrative data

Purpose flag:

supporting study

Study result type:

experimental result

Reliability:

4 (not assignable)

Rationale for reliability incl. deficiencies:

Although, chlorite was tested, the monitoring and methodology were aimed at testing the use of sulfur for reducing chlorite toxicity. Hence the data are of limited use with regard to chlorite toxicity.

Data source

Reference

Reference Type:

publication

Title:

Effectiveness of the sulfur (IV) compound, sodium bisulfite, in reducing chlorine, chlorine dioxide and chlorine toxicity to Daphnia magna in well water and pond water.

Author:

Yonkos LT, Fisher DJ, Burton DT, Whitekettle WK and Petrille JC

Year:

2001

Bibliographic source:

Environmental Toxicology and Chemistry 20(3): 530-536

Materials and methods

Principles of method if other than guideline:

The US EPA (1993) method was followed. Methods for measuring the acute toxicity of effluents to freshwater and marine organisms. 4th Ed. EPA/600/4-90/027F. Cincinnati, OH.

Test materials

Identity of test material same as for substance defined in section 1 (if not read-across):

no

Test material identityopen allclose all

Test material identity 1

Identifier:

CAS number

Identity:

7758-19-2

Test material identity 2

Identifier:

EC number

Identity:

231-836-6

Test material identity 3

Identifier:

IUPAC name

Identity:

sodium chlorite

Test organisms

Test organisms (species):

Daphnia magna

Study design

Test type:

flow-through

Total exposure duration:

48 h

Results and discussion

Any other information on results incl. tables:

There was 100% survival in the control vessels in the pond and well water. Although Sulfur (IV) addition reduced the level of chlorite in the treatments, Daphnia mortality still occurred.

Applicant's summary and conclusion

Conclusions:

Sulfur (IV) compounds are poorly suited for removing chlorite ions in cooling water and wastewater treatment applications where large water volumes and short contact times would likely allow residual chlorite to reach receiving waters as potentially harmful concentrations.

Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of a registration number do

Short-term toxicity to aquatic invertebrates.013

Administrative data

Purpose flag:

weight of evidence

Study result type:

read-across from supporting substance (structural analogue or surrogate)

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

The test substance could not be monitored in the test solutions due to background interference. However, the method allowed accurate determination of the stock solution concentrations in deionised water. As a flow-through system was used, the nominals are considered acceptable estimates of the actual concentrtation.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Materials and methods

Test guideline

Qualifier:

according to

Guideline:

EPA OPP 72-3 (Estuarine/Marine Fish, Mollusk, or Shrimp Acute Toxicity Test)

Deviations:

no

GLP compliance:

yes

Remarks:

no certificate is joined

Test materials

Identity of test material same as for substance defined in section 1 (if not read-across):

no

Test material identityopen allclose all

Test material identity 1

Identifier:

CAS number

Identity:

7758-19-2

Test material identity 2

Identifier:

EC number

Identity:

231-836-6

Test material identity 3

Identifier:

IUPAC name

Identity:

sodium chlorite

Details on test material:

Lot/Batch number: 09-M, PAL M-033
Purity: 80 % 
Further relevant properties: A fine white powder

Details on properties of test surrogate or analogue material:

no data

Analytical monitoring:

yes

Details on sampling:

- Concentrations: 0, 70.6, 121, 252, 504, and 1008 mg/L of sodium chlorite (nominal concentrations)
- Sampling method: no data
- Sample storage conditions before analysis: no data

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: An initial 300000 mg/L stock solution was prepared by combining 750.0 g of test substance and deionized water and adjusting the volume to 2000 mL or by combining 357 g of the test substance and deionized water and adjusting the volume to 1000 mL in a class A volumetric flask.
- Eluate: Deionized water
- Differential loading: no data
- Controls: no data
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): not applicable
- Concentration of vehicle in test medium (stock solution and final test solution): not applicable
- Evidence of undissolved material (e.g. precipitate, surface film, etc): no data

Test organisms

Test organisms (species):

other aquatic crustacea: Eastern Oyster (Crassostrea virginica)

Details on test organisms:

TEST ORGANISM
- Common name: eastern Oyster
- Strain: no data 
- Source: Aquatic Research Organisms division of Resource Analysts Inc. in Hampton.
- Age at study initiation (mean and range, SD): no data
- Weight at study initiation (mean and range, SD): no data
- Length at study initiation (length definition, mean, range and SD): 25-50 mm in height
- Valve height at study initiation, for shell deposition study (mean and range, SD):
- Peripheral shell growth removed prior to test initiation: 3-5 mm
- Method of breeding: phytoplancton in seawater
- Feeding during test
- Food type: phytoplancton
- Amount: no data
- Frequency: no data

ACCLIMATION
- Acclimation period: for more than 10 days.
- Acclimation conditions (same as test or not): in unfiltered seawater
- Type and amount of food: phytoplancton
- Feeding frequency: Oysters were supplied with live marine phytoplankton to supplement the available food in the unfiltered natural seawater.
- Health during acclimation (any mortality observed): During acclimation, oysters were not treated for disease and they were free of apparent sickness, injury, and abnormality at the beginning of the test.

QUARANTINE (wild caught)
- Duration: no data
- Health/mortality: no data

Study design

Test type:

flow-through

Water media type:

saltwater

Limit test:

no

Total exposure duration:

96 h

Post exposure observation period:

no data

Test conditions

Hardness:

no data

Test temperature:

20.4 - 21.2 °C

pH:

7.5 - 9.2

Dissolved oxygen:

7.0 - 8.3 mg/L

Salinity:

25 ppt

Nominal and measured concentrations:

Nominal concentrations of the active substance were 0 (control), 70.6, 121, 252, 504 and 1008 mg sodium chlorite/L
(Doses are equivalent to 0, 53, 90, 188, 376 and 752 mg chlorite/L)

Details on test conditions:

TEST SYSTEM
- Test vessel: class A volumetric glass
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: 19.6 L aquaria, filled with 15 L of test solution
- Aeration:
- Type of flow-through (e.g. peristaltic or proportional diluter): proportional diluter
- Renewal rate of test solution (frequency/flow rate): 18.8 media exchanges per 24 hours.
- No. of organisms per vessel: 20
- No. of vessels per concentration (replicates): 1
- No. of vessels per control (replicates): 1
- No. of vessels per vehicle control (replicates): not applicable
- Biomass loading rate: no data

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: 16:8
- Light intensity: 10 µES-1/m²

TEST CONCENTRATIONS
- Spacing factor for test concentrations: no data
- Justification for using less concentrations than requested by guideline: not applicable 
- Range finding study
- Test concentrations: 0, 70.6, 121, 252, 504, and 1008 mg/L (nominal concentrations)
- Results used to determine the conditions for the definitive study:

Reference substance (positive control):

no

Results and discussion

Effect concentrationsopen allclose all

Effect concentrations 1

Duration:

96 h

Endpoint:

EC0

Remarks:

and NOEC

Effect conc.:

70.6 other: mg sodium chlorite/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shell deposition

Effect concentrations 2

Duration:

96 h

Endpoint:

EC0

Remarks:

and NOEC

Effect conc.:

53 other: mg chlorite/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shell deposition

Effect concentrations 3

Duration:

96 h

Endpoint:

EC50

Effect conc.:

129 other: mg sodium chlorite/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shell deposition

Remarks (e.g. 95% CL):

95% confidence interval of 121 – 138 mg/L

Effect concentrations 4

Duration:

96 h

Endpoint:

EC50

Effect conc.:

96 other: mg chlorite/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: shell deposition

Details on results:

No sub-lethal effects were noted during the exposure period however, after 72 h large and approximately equal amounts of faecal material were present in the control and at 70.6 and 121 mg/L sodium chlorite. The volume of fecal material at concentrations above 121 mg/L appeared to decrease with increasing toxicant concentration. Shell deposition by oysters was related to the concentration of test substance. Exposure of the oysters to sodium chlorite resulted in a 96 h EC50 of 129 mg/L sodium chlorite with a 95% confidence interval of 121 – 138 mg/L (equivalent to 96 mg chlorite/L). The 96 h NOEC was 70.6 mg/L sodium chlorite (equivalent to 53 mg chlorite/L).

Results with reference substance:

not applicable

Reported statistics and error estimates:

Toxicity results were interpreted by standard statistical techniques (Stephan, 1983). EC50 was determined using percent of control growth data and the nominal concentrations of the test substance.

Any other information on results incl. tables:

Table A7_4_1_2(5)-5:        Immobilisation data: Number of live oysters

Test-Substance Concentration (Nominal) [mg sodium chlorite/L]	0 h	24 h	48 h	72 h	96 h
0 (control)	20	20	20	20	20
70.6	20	20	20	20	20
121	20	20	20	20	20
252	20	20	20	20	19
504	20	20	20	20	13
1008	20	20	20	20	2

Table A7_4_1_2(5)-6:        Shell growth at longest finger (mm)

Oyster Number	0.0 mg/l	70.6 mg/l	121 mg/l	252 mg/l	504 mg/l	1008 mg/l
1	2.2	1.9	1.3	0.0	0.0	0.0
2	2.1	1.7	1.0	0.0	0.0	0.0
3	1.9	2.2	1.2	0.0	0.0	-
4	2.4	2.4	1.6	0.2	0.0	-
5	2.1	2.3	1.4	0.0	0.0	-
6	2.1	2.0	1.3	0.0	0.0	-
7	2.3	2.1	1.0	0.1	0.0	-
8	1.9	2.2	0.9	0.0	0.0	-
9	2.3	1.9	1.4	0.0	0.0	-
10	2.2	2.2	1.5	0.0	0.0	-
11	2.0	2.4	1.3	0.0	0.0	-
12	2.4	2.0	1.6	0.0	0.0	-
13	2.0	2.1	1.0	0.1	-	-
14	2.1	2.1	0.7	0.1	-	-
15	2.1	1.7	0.8	0.0	-	-
16	1.8	2.3	1.1	0.0	-	-
17	1.7	2.4	0.9	00	-	-
18	2.2	1.8	1.3	0.0	-	-
19	2.4	2.1	1.2	0.0	-	-
20	2.1	2.0	1.0	0.0	-	-
Mean	2.1	2.1	1.2	0.1	0.0	0.0
Std. dev.	0.2	0.2	0.3	0.1	-	-
% of control	100	100	57.1	1.4	0.0	0.0

Table A7_4_1_2(5)-7:        Effect data

	EC50	95 % c.l.	EC0
96 h [mg sodium chlorite/L]	129 mg/L (n1)	121 – 138 mg/l	70.6 mg/l

1 Effect data are based on nominal (n) concentrations

Applicant's summary and conclusion

Conclusions:

Exposure of the oysters to sodium chlorite resulted in a 96 h EC50 of 129 mg/L sodium chlorite with a 95% confidence interval of 121 – 138 mg/L (equivalent to 96 mg chlorite/L). The 96 h NOEC was 70.6 mg/L sodium chlorite (equivalent to 53 mg chlorite/L).

Executive summary:

Eastern oysters, Crassostrea virginica, were exposed to sodium chlorite in an acute flow-through test, following US EPA procedures (1985, 1988), under GLP. Five concentrations were tested on 20 oysters: 0, 70.6, 121, 252, 504, and 1008 mg/L of sodium chloride (n = 20 per concentration). Exposure experiments resulted in an EC50(96h) = 129 mg/L of sodium chlorite, and a NOEC(96h) = 70.6 mg/L of sodium chlorite.

Validity criteria fulfilled:

yes

Information on Registered Substances comes from registration dossiers which have been assigned a registration number. The assignment of