Sodium hydrogencarbonate

Toxicity to other aquatic organisms

Link to relevant study record(s)

Reference

Endpoint:

toxicity to other aquatic vertebrates

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2014

Reliability:

1 (reliable without restriction)

Qualifier:

according to guideline

Guideline:

other: ASTM E1439-98

Version / remarks:

Standard guide for conducting the frog embryo teratagenesis assay–Xenopus (FETAX). In Annual Book of ASTM Standards, Vol 11.06. Philadelphia, PA, USA.

Qualifier:

according to guideline

Guideline:

other: Atlas of Abnormalities—A Guide to the Performance of FETAX

Version / remarks:

Bantle JA, Dumont JN, Finch RA, Linder G. 1991. Oklahoma State University, Stillwater, OK, USA.

GLP compliance:

not specified

Analytical monitoring:

yes

Details on sampling:

- Sampling method: Experimental water was collected from serial dilutions 1 to 3 times per experiment
- Sample storage conditions before analysis: Anion samples were transported in bicarbonate-rinsed 125-mL polyethylene containers and refrigerated. Cation samples were held in 125-mL I-ChemTM containers and preserved at pH < 2.0. All water samples were refrigerated and sent to the Montana Department of Health and Human Services laboratory in Helena, Montana (USA), for analyses.

Vehicle:

no

Details on test solutions:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: exposure water containing increasing concentrations of NaHCO3 was added to create a range of exposures from a control to up to 3823 mg/L NaHCO3, depending on the sensitivity of the organism determined during range-finding experiment.

Aquatic vertebrate type (other than fish):

frog

Test organisms (species):

Xenopus laevis

Details on test organisms:

TEST ORGANISM
- Common name: African clawed frogAfrican clawed frog
- Strain: The African clawed frog (Xenopus laevis) was selected as a surrogate amphibian species. Ideally, the native northern leopard frog (Rana pipiens), an amphibian native to the Powder and Tongue River Basins, would have been used as an experimental animal. However, because of logistical problems with obtaining eggs and adults at the proper life stage for experiments, and the lack of an approved disease-free source of experimental animals, the clawed frog was used.
- Age at study initiation (mean and range, SD): Embryos

Test type:

semi-static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

96 h

Test temperature:

22–24 C

Nominal and measured concentrations:

265–3823 mg/L NaHCO3

Details on test conditions:

TEST SYSTEM
- Test vessel: 10-mL acid-washed Petri dishes
- Renewal rate of test solution (frequency): water replaced every 24h
- No. of organisms per vessel: 25
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water:
Tongue river recostituted water (check table in other info on methodfor water description). The reconstituted water was created using a combination of well water from the Jackson Field Research Station, Jackson, Wyoming (USA) and the addition of chemicals of American Chemical Society (ACS) grade or higher or were created at the Montana Fish Wildlife and Parks, Helena, Montana (USA) laboratory using deionized water and chemicals of ACS grade or higher.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
median lethal concentration

TEST CONCENTRATIONS
- Results from range finding used to determine the conditions for the definitive study: yes

Reference substance (positive control):

no

Key result

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1 940 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

no data

Results with reference substance (positive control):

not applicable

Reported statistics and error estimates:

Median lethal concentrations were calculated with the Toxicity Relationship Analysis Program (TRAP) using measured NaHCO3 and HCO3 values. The predicted toxicity of salt combinations in experimental waters was tested on fathead minnows and C. dubia using the salinity toxicity relationship (STR) model

Validity criteria fulfilled:

not specified

Conclusions:

Short term exposure of embryos of african clawed frog to NaHCO3 resulted in a LC50 of 1940 mg/l.

Executive summary:

A study was conducted exposing for 96 h embryos ofafrican clawed frog, Xenopus laevis, to a range concentration 265–3823 mg/L of NaHCO₃. Experiments were conducted following the standard ASTM guideline E1439-98 "Standard guide for conducting the frog embryo teratagenesis assay–Xenopus (FETAX) ”, in reconstituted river water (Tongue). Results showed an LC50 of 1940 mg/l NaHCO₃.

Description of key information

A study was conducted exposing for 96 h embryos of african clawed frog, Xenopus laevis, to a range concentration 265–3823 mg/L of NaHCO₃. Experiments were conducted following the standard ASTM guideline E1439-98 "Standard guide for conducting the frog embryo teratagenesis assay–Xenopus (FETAX)”, in reconstituted river water (Tongue). Results showed an LC50 of 1940 mg/l NaHCO₃.