Calcium nitrite

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

11-13 January 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Good quality study, conducted to GLP. Certain water quality parameters (e.g. hardness, conductivity and heavy metal concentrations) were not reported. The test material was a 34% solution of hydrated calcium nitrite.

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

yes

Remarks:

Certain water quality parameters (e.g. hardness, conductivity and heavy metal concentrations) were not reported.

Qualifier:

according to guideline

Guideline:

EU Method C.2 (Acute Toxicity for Daphnia)

Version / remarks:

29.12.92

Deviations:

yes

Remarks:

Certain water quality parameters (e.g. hardness, conductivity and heavy metal concentrations) were not reported.

GLP compliance:

yes

Analytical monitoring:

no

Details on sampling:

Not applicable

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance was dissolved in test water (Elendt M7 medium) to give an initial stock solution of 100 mg/L. Serial dilutions of this stock solution were prepared with test water to give the desired series of exposure levels.
- Eluate: not applicable
- Differential loading: not applicable
- Controls: water
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): not applicable
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): not applicable
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): none reported

Test organisms (species):

Daphnia magna

Details on test organisms:

TEST ORGANISM
- Common name: Daphnia magna (Straus)
- Strain/clone: no data
- Justification for species other than prescribed by test guideline: not applicable
- Source: Laboratory culture originating from a strain supplied by the Institute National de Recherche Chimique Appliquée (IRChA), France
- Age of parental stock (mean and range, SD): no data
- Feeding during test: no

ACCLIMATION
- Acclimation period: no data
- Acclimation conditions (same as test or not): essentially the same as the test
- Type and amount of food: suspension of mixed algae (predominantly Scenedesmus and Selenastrum spp), amount not specified
- Feeding frequency: daily
- Health during acclimation (any mortality observed): none reported

QUARANTINE (wild caught): not applicable

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: Gravid adults were isolated 24 hours prior to initiation of the test and young daphnids produced overnight were used for testing.

Test type:

static

Water media type:

other: reverse osmosis purified water

Remarks:

Elendt M7 medium

Limit test:

no

Total exposure duration:

48 h

Remarks on exposure duration:

As recommended in the relevant test guideline

Post exposure observation period:

Not applicable

Hardness:

No data

Test temperature:

20 deg C

pH:

7.5-7.8

Dissolved oxygen:

8.8-9.2 mg(O2)/L

Salinity:

Reverse osmosis purified water (i.e. non-saline)

Conductivity:

No data

Nominal and measured concentrations:

2.2, 4.6, 10, 22, 46 and 100 mg/L (nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass jars
- Type (delete if not applicable): closed (loosely covered with aluminium foil to minimise evaporation losses)
- Material, size, headspace, fill volume: each vessel contained 200 mL of prepared test medium or diluent media as appropriate, to give a loading of 20 mL test solution/organism
- Aeration: no
- Type of flow-through (e.g. peristaltic or proportional diluter): not applicable
- Renewal rate of test solution (frequency/flow rate): test media was not renewed during the exposure period
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No. of vessels per vehicle control (replicates): not applicable
- Biomass loading rate: no data

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Elendt M7 medium was prepared using analytical grade reagents and reverse osmosis purified water. The medium contained the following substances (in mg/L): H3BO3 (0.71); MnCl2.4H2O (0.090); LiCl (0.077); RbCl (0.018); SrCl2.6H2O (0.038); NaBr (0.0040); Na2MoO4.2H2O (0.16); CuCl.2H2O (0.0042); ZnCl2 (0.013); CoCl2.6H2O (0.010); KI (0.0033); Na2SeO3 (0.0022); NH4VO3 (0.00058); Fe-EDTA solution (1.7); CaCl2.2H2O (294); MgSO4/7H2O (123); KCl (5.80); NaHCO3 (64.8); Na2SiO3.5H2O (6.83); NaNO3 (0.274); KH2PO4 (0.143); K2HPO4 (0.184); Thiamine hydrochloride (0.075); Cyanocobalamine (B12; 0.0010); Biotine (0.00075)
- Total organic carbon: no data
- Particulate matter: no data
- Metals: no data
- Pesticides: no data
- Chlorine: no data
- Alkalinity: no data
- Ca/mg ratio: no data
- Conductivity: no data
- Salinity: no data
- Culture medium different from test medium: no
- Intervals of water quality measurement: no data

OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod: 16 hr light / 8 hr dark
- Light intensity: no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Immobilisation (if the organisms were unable to swim for approximately 15 seconds after gentle agitation), observed daily

VEHICLE CONTROL PERFORMED: not applicable

RANGE-FINDING STUDY: not applicable

Reference substance (positive control):

not required

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Effect level is equivalent to >34 mg/kg bw as calcium nitrite

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

45 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: Effect level is equivalent to 15.3 mg/kg bw as calcium nitrite

Details on results:

The highest concentration resulting in 0% immobilisation at 48 hours was 10 mg/L; at 22, 46 and 100 mg/L (the highest concentration tested) immobilisation was 20, 55 and 80%, respectively.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

The 95% confidence limits of the 48-hr EC50 (45 mg/L) were 32.0 and 63.3 mg/L.

Individual pH, temperature and dissolved oxygen values remained within acceptable limits throughout the duration of the study.

Validity criteria fulfilled:

yes

Conclusions:

In a guideline study, to GLP, the 48-hr EC50 of calcium nitrite (hydrate) was determined to be 45 mg/L in freshwater Daphnia magna (Kelly, 1996b).

Executive summary:

In an OECD Test Guideline 202 study, conducted according to GLP, calcium nitrite (hydrate) was studied for acute toxicity to freshwater Daphnia magna. The test material (DCI) was available as a 34% aqueous solution of calcium nitrite. Young daphnids (10/group, tested in duplicate) were exposed to test substance concentrations of 0 (control), 2.2, 4.6, 10, 22, 46 or 100 mg/L (nominal; dissolved in test medium) for 48 hours. Immobilisation readings were made at 24 and 48 hours and were used to calculate EC50 values and 95% confidence limits.

No immobilisation was observed at up to 10 mg/L. Immobilisation values of 20, 55 and 80% were reported at 22, 46 and 100 mg/L. Environmental parameters (including pH, temperature, and dissolved oxygen) remained within acceptable limits. The 48-hr EC50 for the test material was determined to be 45 mg/L (95% confidence limit 32.0-63.3 mg/L).

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

22-26 January 1996

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Good quality study, conducted to GLP. Minor protocol deviations, omission of a single time point and a slight temperature deviation, that did not affect study outcome. Certain water quality parameters (e.g. hardness, conductivity) were not reported. The test material was a 34% solution of hydrated calcium nitrite.

Qualifier:

according to guideline

Guideline:

other: guidelines issued by the UK Ministry of Agriculture, Fisheries and Food, Directorate of Fisheries Research (AEP2, MAFF)

Version / remarks:

September 1984

Deviations:

yes

Remarks:

A slight temperature deviation and absence of 6-hr observation time point did not affect the study outcome.

GLP compliance:

yes

Analytical monitoring:

no

Details on sampling:

Not applicable

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: The test substance was dissolved in test water and made up to 2 L to give an initial stock solution of 1000 mg/L. This stock solution was added to the test tank and made up to 20 L at the desired exposure level.
- Eluate: not applicable
- Differential loading: not applicable
- Controls: water
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): not applicable
- Concentration of vehicle in test medium (stock solution and final test solution(s) or suspension(s) including control(s)): not applicable
- Evidence of undissolved material (e.g. precipitate, surface film, etc.): none reported

Test organisms (species):

Crangon crangon

Details on test organisms:

TEST ORGANISM
- Common name: Brown shrimp
- Strain/clone: Crangon crangon
- Justification for species other than prescribed by test guideline: not applicable
- Source: P. Garnett, Kings Lynn, Norfolk, UK
- Age of parental stock (mean and range, SD): no data
- Feeding during test: no
- Length at study initiation (length definition, mean, range and SD): mean standard length was 4.6 cm, SD = 0.4 cm
- Weight at study initiation (mean and range, SD): mean weight was 1.19 g, SD = 0.35 g

ACCLIMATION
- Acclimation period: 7 days
- Acclimation conditions (same as test or not): very similar
- Type and amount of food: The shrimp were not fed during the acclimitisation period
- Feeding frequency: not applicable
- Health during acclimation (any mortality observed): 5% mortality reported

QUARANTINE (wild caught): not applicable

METHOD FOR PREPARATION AND COLLECTION OF EARLY INSTARS OR OTHER LIFE STAGES: not applicable

OTHER: Temperature remained within range 15 +/- 1oC and dissolved oxygen in the range 7.5 +/-0.1 mgO2/L

Test type:

semi-static

Water media type:

saltwater

Limit test:

yes

Total exposure duration:

96 h

Remarks on exposure duration:

Standard duration.

Post exposure observation period:

Not applicable

Hardness:

No data

Test temperature:

13 deg C [The temperature deviation (12-14°C compared to the protocol range 14-17°C) had no effect on the study outcome.]

pH:

8.1-8.2

Dissolved oxygen:

9.9-10.0 mg(O2)/L

Salinity:

32 ± 2%

Conductivity:

No data

Nominal and measured concentrations:

100 mg/L (nominal limit test)

Details on test conditions:

TEST SYSTEM
- Test vessel: glass aquaria (25 x 46 x 25 cm)
- Type (delete if not applicable): open
- Material, size, headspace, fill volume: each vessel contained 20 L of medium to a depth of 19 cm. This provided an intial loading of 1.19 g bodyweight/L (static volume).
- Aeration: "Supplementary aearation was provided via narrow glass tubes"
- Type of flow-through (e.g. peristaltic or proportional diluter): not applicable
- Renewal rate of test solution (frequency/flow rate): Daily batchwise renewal of test media
- 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

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Synthetic sea water (Synthetica, Waterlife Research Ltd.) prepared from softened, dechlorinated tap water and aerated for at least 12 hours prior to use. The test substance was dissolved in test water to give an initial 2 L stock solution of 1000 mg/L. This stock solution was added to the test tank and made up to 20 L at the desired exposure level.
- Total organic carbon: no data
- Particulate matter: no data
- Metals: no data
- Pesticides: no data
- Chlorine: no data
- Alkalinity: no data
- Ca/mg ratio: no data
- Conductivity: no data
- Salinity: 32 ± 2%
- Culture medium different from test medium: no data
- Intervals of water quality measurement: no data

OTHER TEST CONDITIONS
- Adjustment of pH: no data
- Photoperiod: 16 hr light / 8 hr dark
- Light intensity: no data

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, measured by the absence of respiratory movement and lack of response to external stimuli. Subjective measurements on the type and incidence of sub-lethal effects, as compared to controls, were also made. Observations (lethal and sub-lethal) were made at 3, 24, 48, 72 and 96 hr. [This is a minor deviation from the protocol which stated 3, 6, 24, 48, 72 and 96 hr. No significant effects were observed at any stage, as such this deviation (lack of a 6 -hr observation) did not affect the study outcome.]

VEHICLE CONTROL PERFORMED: not applicable

RANGE-FINDING STUDY: not applicable

Reference substance (positive control):

not required

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: Effect level is equivalent to >34 mg/kg bw as calcium nitrite

Details on results:

There was no mortality in brown shrimp exposed to water containing a nominal test material concentration of 100 mg/L for 96 hours. In both the control and treated groups there were a small number (2 and 3, respectively) of cannibalised shrimps recorded over the study period (this is not unusual for this species, when held in groups, and is not considered to have affected the results of the study). No sub-lethal effects were observed during the study.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Not applicable

Individual pH, temperature, dissolved oxygen and salinity values remained within acceptable limits throughout the duration of the study.

Validity criteria fulfilled:

not specified

Conclusions:

In a guideline study, to GLP, there was no mortality in brown shrimp exposed to reconstituted sea water containing calcium nitrite (hydrate) at a nominal limit concentration of 100 mg/L for 96 hours. No sub-lethal effects were observed.

Executive summary:

In a GLP study conducted according to UK MAFF guidelines, calcium nitrite (hydrate) was studied for acute toxicity to brown shrimp (Crangon crangon), under semi-static conditions. The test substance (DCI), available as a 34% aqueous solution of calcium nitrite, was added to synthetic sea water and the shrimp (20/group) exposed at 0 or 100 mg/L (nominal) for 96 hours.

 

There was no mortality or other significant treatment-related adverse effects observed in the shrimp. Both control and treated groups contained a small number of cannibalised shrimp; this finding was considered unremarkable by the study investigators and deemed not to have influenced the study outcome. Environmental parameters (including pH, temperature, dissolved oxygen and salinity) remained within acceptable limits.

 

Based on these results, and in the absence of any mortality, the 96-hr LC50 for the test material was concluded to be >100 mg/L. Similarly, given the lack of sub-lethal effects in the study, 100 mg/L is considered to be the study NOAEC.

Description of key information

In a GLP study conducted according to OECD Test Guideline 202, the 48-hr EC50 of calcium nitrite (hydrate) was determined to be 45 mg/L in freshwater Daphnia magna (Kelly, 1996b).

 

In another GLP study, conducted according to UK MAFF guidelines, there was no mortality in brown shrimp exposed to reconstituted sea water containing calcium nitrite (hydrate) at a nominal limit concentration of 100 mg/L for 96 hours. No sub-lethal effects were observed (Kelly, 1996c).

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

15.3 mg/L

Additional information

In an OECD Test Guideline 202 study, conducted according to GLP, calcium nitrite (hydrate) was studied for acute toxicity to freshwater Daphnia magna. The test material (DCI) was available as a 34% aqueous solution of calcium nitrite. Young daphnids (10/group, tested in duplicate) were exposed to test substance concentrations of 0 (control), 2.2, 4.6, 10, 22, 46 or 100 mg/L (nominal; dissolved in test medium) for 48 hours. Immobilisation readings were made at 24 and 48 hours and were used to calculate EC50 values and 95% confidence limits. No immobilisation was observed at up to 10 mg/L. Immobilisation values of 20, 55 and 80% were reported at 22, 46 and 100 mg/L. Environmental parameters (including pH, temperature, and dissolved oxygen) remained within acceptable limits. The 48-hr EC50 for the test material was determined to be 45 mg/L (95% confidence limit 32.0-63.3 mg/L) [equivalent to 15 mg/L as calcium nitrite] (Kelly, 1996b).

 

In a GLP study conducted according to UK MAFF guidelines, calcium nitrite (hydrate) was studied for acute toxicity to brown shrimp (Crangon crangon), under semi-static conditions. The test substance (DCI), available as a 34% aqueous solution of calcium nitrite, was added to synthetic sea water and the shrimp (20/group) exposed at 0 or 100 mg/L (nominal) for 96 hours. There was no mortality or other significant treatment-related adverse effects observed in the shrimp. Both control and treated groups contained a small number of cannibalised shrimp; this finding was considered unremarkable by the study investigators and deemed not to have influenced the study outcome. Environmental parameters (including pH, temperature, dissolved oxygen and salinity) remained within acceptable limits. Based on these results, and in the absence of any mortality, the 96-hr LC50 for the test material was concluded to be >100 mg/L. Similarly, given the lack of sub-lethal effects in the study, 100 mg/L is considered to be the study NOAEC (Kelly, 1996c).

 

As with fish, there is variation in sodium nitrite toxicity between invertebrate species; 96-hr LC50 values ranging from 4.93 mg/L (for Cherax quadricarinatus [Australian redclaw crayfish]) to 539.2 mg/L (for Penaeus paulensis [San paulo shrimp] have been reported in the literature. The presence of chloride ions has been found to mitigate nitrite toxicity in some species (OECD, 2005).