Potassium carbonate

Short-term toxicity to fish

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1993-12-31 to 1994-01-04

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

other: FIFRA Guideline 72-1 (national standard, US, comparable to international guidelines)

GLP compliance:

yes

Analytical monitoring:

yes

Vehicle:

no

Test organisms (species):

Oncorhynchus mykiss (previous name: Salmo gairdneri)

Details on test organisms:

TEST ORGANISM
- Common name: Rainbow trout
- Source: Mount Lassen Trout Farm, Red Bluff, California
- Length at study initiation (length definition, mean, range and SD): mean: 52 mm (range: 41 - 58 mm, N=30)
- Weight at study initiation (mean and range, SD): mean wet weight: 1.4 g (range: 0.78 - 2.0, N=30)
- Method of breeding: not reported
- Feeding during test:not reported

ACCLIMATION: not reported

Test type:

flow-through

Water media type:

freshwater

Total exposure duration:

96 h

Hardness:

Total hardness as CaCO3: 11 - 39 mg/L

Test temperature:

11 - 12 °C

pH:

6.4 - 7.3

Nominal and measured concentrations:

nominal test concentrations: 18, 30, 50, 83, 140 and 230 mg a.i./L
measured test concentartions: 17, 33, 54, 85, 150 and 230 mg a.i./L

Details on test conditions:

TEST SYSTEM: Not reported, only excerpts of study report available

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Well water supplemented with Town of Wareham well wa
ter
- Total organic carbon: not reported
- Conductivity: 50 - 130 μmhos/cm
- Culture medium different from test medium: no reported
- Intervals of water quality measurement: not reported


OTHER TEST CONDITIONS
- Adjustment of pH: not reported
- Photoperiod: 16 hours light, 8 hours dark
- Light intensity: 26 to 100 footcandles at test termination


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : mortality


TEST CONCENTRATIONS: Not reported, only excerpts of study report available

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

68 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 61 - 75 mg a.i./L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

33 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Reported statistics and error estimates:

LC 50 was calculated by probit analysis.

Validity criteria fulfilled:

not specified

Remarks:

no data (Not reported, only excerpts of study report available)

Conclusions:

In a 96-h acute toxicity study according to national guideline FIFRA Guideline 72-1 the 96-h LC50 for Rainbow trouts (Oncorhynchus mykiss) was 68 mg a.i./L (95% CL: 61 - 75 mg a.i./L). The NOEC, based on mortality, was 33 mg a.i./L.

Executive summary:

In a 96-h acute toxicity study according to national guideline FIFRA Guideline 72-1, Rainbow trouts (Oncorhynchus mykiss) were exposed to Potassium carbonate at measured concentrations of 17, 33, 54, 85, 150 and 230 mg a.i./L under flow through conditions.  The 96-h LC₅₀was 68 mg a.i./L. The NOEC, based on mortality, was 33 mg a.i./L. 

 

This toxicity study is classified as reliable with restrictions and satisfies the guideline requirement for acute toxicity study to fish.

 

Results Synopsis 

Test Type (Flowthrough): FIFRA Guideline 72-1

 

LC₅₀: 68 mg a.i./L                         95% CL: 61 - 75 mg a.i./L

NOEC: 33mg a.i./L

 

Endpoint(s) Effected: mortality

 

Description of key information

96-h LC50 for rainbow trout (Oncorhynchus mykiss) was 68 mg a.i./L (95% CL: 61 - 75 mg a.i./L). Despite of this, potassium carbonate is an alkaline substance, which dissociates completely to form potassium cations (K+) and inorganic carbon species. Depending on pH of the receiving waters CO2 is the predominant species at pH values below 6.35, while HCO3- is the predominant species at a pH in the range between 6.35 and 10.33 and CO3 2- is the predominant species at pH values above 10.33. In the majority of the natural waters, pH levels are between 6 and 10. Thus HCO3- (pKa= 10.33) is the most important species for the buffer capacity. Therefore the pH will remain between environmentally expected ranges.

Overall, potassium carbonate is not expected to have an intrinsic toxic activity to aquatic organisms.

Additional information

In a 96-h acute toxicity study according to national standard (US), comparable to international guideline FIFRA Guideline 72-1 the 96-h LC50 for Rainbow trouts (Oncorhynchus mykiss) was 68 mg a.i./L (95% CL: 61 - 75 mg a.i./L). The NOEC, based on mortality, was 33 mg a.i./L. In a second 96-h acute toxicity study according to national guideline FIFRA Guideline 72-1 the toxicity to Bluegill sunfish (Lepomis macrochirus) was considerably lower. The 96-h LC50 was determined to be 230 mg a.i./L (95% CL: 140 - 240 mg a.i./L). The NOEC, based on mortality, was 140 mg a.i./L.