Potassium hydrogencarbonate

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:

1993-05-28 to 1993 to 1993-06-01

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Basic data given, comparable to guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Test solutions were analysed at test initiation (0 hour) and at test termination (96 hours).

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: 40 mm (range: 32 - 45 mm, N=30)
- Weight at study initiation (mean and range, SD): mean wet weight: 0.52 g (range: 0.40 - 0.65, N=30)
- Method of breeding: not reported
- Feeding during test: yes

ACCLIMATION: fish were maintained under conditions similar to test conditions for 14 days prior to testing

Test type:

flow-through

Water media type:

freshwater

Total exposure duration:

96 h

Hardness:

Total hardness as CaCO3: 23 - 27 mg/L

Test temperature:

12±1°C

pH:

6.9 - 7.0

Nominal and measured concentrations:

nominal test concentrations: 160, 260, 430, 720, 1200 and 2000 mg/L
mean measured concentrations: 160, 270, 430, 690, 1200 and 1900 mg a.i./L

Details on test conditions:

TEST SYSTEM
- Test vessel: aquaria
- Type: open / closed: not reported
- Material, size, headspace, fill volume: not reported
- Aeration:
- Type of flow-through (e.g. peristaltic or proportional diluter): intermittent-flow proportional diluter apparatus
- Renewal rate of test solution (frequency/flow rate): 6.6 aquarium volumes per day
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- Biomass loading rate: not reported

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Well water
- Total organic carbon: 0.82 - 1.5 mg/L
- Conductivity: 110 - 120 μmhos/cm
- Culture medium different from test medium: no
- Intervals of water quality measurement: monthly TOC analysis

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

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



OTHER TEST CONDITIONS
- Adjustment of pH: not reported
- Photoperiod: 16 hours light, 8 hours dark
- Light intensity: 20 to 100 footcandles throughout the study period


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

Duration:

96 h

Dose descriptor:

LC50

Effect conc.:

1 300 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

act. ingr.

Basis for effect:

mortality (fish)

Remarks on result:

other: 95% CL: 1200 - 1900 mg/L

Duration:

96 h

Dose descriptor:

NOEC

Effect conc.:

430 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 estimated by nonlinear interpolation
95% interval calculated by binominal probability

Sublethal observations / clinical signs:

Table 1: Test results

 

Exposure time[h]	LC50[mg/L]^a	95% Confidence interval	NOEC^a
96	1300^c	1200 - 1900	430
72	1400^c	1200 - 1900	-
48	1400^c	1200 - 1900	-
24	1500^b	1300 - 1700	-

 

^aBased on mean measured concentrations expressed as Potassium Bicarbonate

^bLC50 value and 95% confidence interval calculated by probit analysis

^cLC50 value estimated by nonlinear interpolation; 95% confidence interval calculated by binominal probability

 

 

Following 48 hours of exposure, 100% mortality was observed among fish exposed to the highest mean measured concentration tested (1900 mg/L). At test termination (96 hours), mortality of 35% was observed among fish exposed to 1200 mg/L treatment level.

 

No mortality was observed among fish exposed to the remaining concentrations tested (160 to 690 mg/L).

 

Sublethal effects (i.e., partial loss of equilibrium, erratic swimming behaviour) were observed among two of the surviving fish exposed to the 690 and 1200 mg/L treatment levels.

 

 

 

 

Validity criteria fulfilled:

not specified

Remarks:

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 1300 mg a.i./L (95% CL: 1200 - 1900 mg a.i./L). The NOEC, based on mortality, was 430 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 160, 270, 430, 690, 1200 and 1900 mg a.i./L under flow through conditions.  The 96-h LC₅₀was 1300 mg a.i./L. The NOEC, based on mortality, was 430 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 organism size :   mean length: 40 mm (range: 32 - 45 mm, N=30)

                                  mean wet weight: 0.52 g (range: 0.40 – 0.65, N=30)

Test Type (Flow through): FIFRA Guideline 72-1

 

LC₅₀: 1300 mg a.i./L                         95% CL: 1200 - 1900 mg a.i./L

NOEC: 430mg a.i./L

 

Endpoint(s) Effected: mortality

 

 

Description of key information

The 96-h LC50 for Rainbow trout is 1300 mg a.i./L. The NOEC, based on mortality, is 430 mg a.i./L.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish

Effect concentration:

1 300 mg/L

Additional information

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 1300 mg a.i./L (95% CL: 1200 - 1900 mg a.i./L). The NOEC, based on mortality, was 430 mg a.i./L.