Sodium hydrogencarbonate

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

In the OECD SIDS on sodium bicarbonate (2002) a similar reliability was assigned.

Qualifier:

according to guideline

Guideline:

EPA OPP 72-2 (Aquatic Invertebrate Acute Toxicity Test)

Deviations:

yes

Remarks:

Alkalinity in the controls were not measured at test initiation, but at test termination

GLP compliance:

yes

Analytical monitoring:

yes

Test organisms (species):

Daphnia magna

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Nominal and measured concentrations:

- Nominal/ measured concentrations in mg A.I./ L
Nominal: 780 Mean Measured (SD):630 (57)
Nominal: 1300 Mean Measured (SD):1100 (81)
Nominal: 2200 Mean Measured (SD):1800 (190)
Nominal: 3600 Mean Measured (SD):3100 (280)
Nominal: 6000 Mean Measured (SD):5400 (400)

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

3 100 mg/L

Nominal / measured:

meas. (not specified)

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

4 100 mg/L

Nominal / measured:

meas. (not specified)

Basis for effect:

mobility

Reported statistics and error estimates:

Moving average angle analysis, probit analysis and nonlinear interpolation with 95% confidence intervals calculated by binominal probability.
METHOD OF CALCULATION: the 24-, 48-, 72- and 96-hour median LC50 values were estimated from derived mortality data at the measured concentrations using the described statistical methods which were available in a computer programme. If two or more statistical methods produced acceptable results, then the method which yielded the smallest 95% confidence interval was selected.

- Concentration / response curve:
Mean percentage mortality (of vessel A and B) after 96 hours:
Control: 5 %
630 mg A.I./L: 0 %
1100 mg A.I./L: 0 %
1800 mg A.I./L: 5 %
3100 mg A.I./L: 0 %
5400 mg A.I./L: 100 %
- Effect concentration vs. test substance solubility: Not reported
- Other effects: Not reported

RESULTS CONTROL: No effects

Conclusions:

48-hr acute flow-through test, Daphnia magna, showed a NOEC of 3,100 mg/l and a LC50 of 4,100 mg/l.

Executive summary:

A study was conducted exposing for 48-hr flow-through test the water flea, Daphnia magna, to NaHCO₃ at concentration ranging from 780 to 6,000 mg/L, following the EPA OPP 72-2 “Aquatic Invertebrate Acute Toxicity Test” guideline. Results showed a NOEC of 3,100 mg/l and a LC50 of 4,100 mg/l.

Description of key information

Only one study was performed by GLP standard (Putt, 1993) is available and so it was chosen as key study. Putt (1993) studied, in a 48-hr acute flow-through test, Daphnia magna exposed to NaHCO3at concentration ranging from 780 to 6,000 mg/L, following the EPA OPP 72-2 “Aquatic Invertebrate Acute Toxicity Test” guideline. Results showed a NOEC of 3,100 mg/l and a LC50 of 4,100 mg/l.

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

4 100 mg/L

Additional information

Two reliable (K 2) studies (Hoke et al., 1992 and Mount et al.,1997) reported in the OECD SIDS (2002) on sodium bicarbonate, exposed the cladocera, Daphnia magna and Ceriodaphnia sp, for 48h to NaHCO₃. Results showed a EC50 for immobilization of 1,268-1,640 mg/l and 1,020-1,268 mg/L, respectively.

Furthermore, a reliable publication (Harper et al., 2014) was available reporting data on 5 different invertebrates: the chironomid Chironomus dilutus (7 -14 dph); the worm Tubifex tubifex (adults); the amphipod Hyalella azteca (adults); the freshwater mussel Lampsilis siliquoidea (newly transformed juveniles) and water flea Ceriodaphnia dubia (neonates). Test were conducted following the EPA guideline 821/R-02/012 “Methods for measuring the acute toxicity of effluents and receiving waters to freshwater and marine organisms, 5th ed”, with the exception of ASTM International E2455-06 “Standard guide for conducting laboratory toxicity tests with freshwater mussels ”for experiments with mussels. Experiments were run in 2 different medium, reconstituted Tongue river water and reconstituted Powder river water for all the species, with exception of test with mussels which were run only in reconstituted Tongue river water. Results showed a LC50 ranging from 989 to 8,014 mg/L NaHCO₃, depending on the species and the medium used.