Potassium (S)-lactate

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:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Vehicle:

no

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

240 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Details on results:

Test solutions were not neutralised. Effects on the mobility of the daphnids are hence likely to be caused by the low pH value. At the highest test concentration a pH of 3.6 (t = 0 h) was measured.

The apparent toxicity of lactic acid to Daphnia can be explained by the low pH values of the test substance solutions. At the highest test concentration a pH of 3.6 (t = 0 h) was measured.

Validity criteria fulfilled:

yes

Conclusions:

The 48 h EC50 (immobilisation) of lactic acid to Daphnia magna is 130 mg/L, which can be attributed to a pH effect.

Executive summary:

The acute toxicity of the test material, a solution of about 80 % L-(+)-lactic acid, to the fresh-water crustacean Daphnia magna was determined as described in the OECD guideline no. 202 and according to the OECD principles of Good Laboratory Practice.

The test was carried out with 4 × 5 daphnias (quadruplicate test solutions) at each concentration, and the test solutions were not replaced. The exposure duration was 48 hours. The nominal concentrations tested were 32, 56, 100, 180, 320 and 560 mg/L.

At the start of the test the test substance appeared to be completely dissolved at all concentrations tested (visually assessed).

The actual concentrations of L-(+)-lactic acid were determined enzymatically with a Boehringer test kit. They were between 42 and 76 % of nominal just after dosing (average 59 %). To test the stability, the concentrations of L-(+)-lactic acid were also analysed at the end of the test and were between 58 and 78 % of nominal (average 71 %).

The results of the test were (as nominal concentrations):

24 h EC50 (mobility): 240 mg/L

48h EC50 (mobility): 240 mg/L

48h EC100 (mobility) 320 mg/L

The apparent toxicity of lactic acid to Daphnia can be explained by the low pH values of the test substance solutions. At the highest test concentration a pH of 3.6 (t = 0 h) was measured.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reference 2

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

ca. 240 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Remarks on result:

other: 95 % CL = 180-320

Details on results:

- Behavioural abnormalities: No data
- Observations on body length and weight: No data
- Other biological observations: No data
- Mortality of control: No data
- Other adverse effects control: No data
- Abnormal responses: No data
- Effect concentrations exceeding solubility of substance in test medium: No

Validity criteria fulfilled:

not specified

Conclusions:

The short-term toxicity testing of lactic acid on freshwater invertebrates (Daphnia magna) resulted in an EC50 (48 h) of 240 mg/L (nominal), which can be attributed to a pH effect.

Executive summary:

In a 48-h acute toxicity study, water fleas (Daphnia magna) were exposed to L-(+)-lactic acid at nominal concentrations of 0 (control), 320 and 560 mg/L (further information on the number of concentration levels not available) under static conditions. The 48-h EC₅₀ was 240 mg/L. The observed effects can be attributed to a pH effect. Sublethal effects were not reported. Based on the results of this study, L-(+)-lactic acid would not be classified as hazardous to the aquatic environment according to the CLP Regulation (EC) No 1272/2008.

This toxicity study is classified as supplementary information and does not satisfy the guideline requirement for an invertebrate short-term toxicity study but can nevertheless be used as supportive data or in a weight-of-evidence approach.

Results synopsis

Test organism: Water flea (Daphnia magna)

Test type: Static

EC50: 240 mg/L

Endpoint(s) effected: Mobility

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reference 3

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

320 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

750 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

The 24 and 48-hour LC50 values for SY-83 were both 750 mg/L, respectively. All results were based on the nominal concentrations of 100, 180, 320, 560 and 1,000 mg/L. The no-effect concentration, based on the lack of mortality and abnormal effects, was 320 mg/L after 48 hours. The abnormal effects of mortality and/or erratic movement were observed in the 560 and 1,000 mg/L test concentrations. The dissolved oxygen concentrations ranged between 7.1 and 8.5 mg/L. These values represented 77 and 92 percent saturation at 20 °C, respectively, and were considered adequate for testing. The pH values of the treated chambers were consistent with the control and ranged from 4.3 to 8.5, with pH values decreasing with an increase in test concentrations. The study was conducted following the intent of the Good Laboratory Practice Regulations and the final report was reviewed by Analytical Bio-Chemistry Laboratories1 Quality Assurance Unit. All original raw data was provided to Union Oil Company, with a copy retained at Analytical Bio-Chemistry Laboratories.

Reported statistics and error estimates:

See table 1

Table 1: Acute toxicity of SY-83 to Daphnia magna.

	LC50 (mg/L)
Compound	24 h	48 h
SY-83	750 (95 % CI: 560–1000)	750 (95 % CI: 560–1000)

Validity criteria fulfilled:

yes

Conclusions:

The acute toxicity of SY-83 to Daphnia magna was assessed using the methods outlined by the Committee on Methods for Toxicity Tests with Aquatic Organisms. Water quality parameters of temperature, dissolved oxygen and pH were measured at the termination of the test and were within acceptable limits. The results of the 48 hour static Daphnia magna toxicity study is: LC50 (48h) = 750 mg/L. All reported values were based upon nominal concentrations. The no effect level observed for SY-83 was 320 mg/L after 48 hours, which was based on the lack of mortality and abnormal effects.

Executive summary:

The 48-hr-acute toxicity of L(+) lactic acid to Daphnia magna was studied under static conditions. Daphnids were exposed to control, and test chemical at nominal concentrations of 100, 180, 320, 560 and 1,000 mg/L for 48 hr. Mortality and sublethal effects were observed daily. The 48-hour LC₅₀ was 750 mg/L. The 48-hr NOEC based on mortality and lack of abnormal effects was 320 mg/L.

Based on the results of this study, L(+) lactic acid would not be classified as toxic toDaphnia magnain accordance with the CLP Regulation (EC) No 1272/2008.

This study is classified as acceptable and satisfies the guideline requirements for an acute toxicity study with freshwater invertebrates.

Results synopsis

Test organism age (e.g. 1^st instar): < 24 h old

Test type: Static

LC₅₀: 750 mg/L (95% C.I.: 560–1000 mg/L)

NOEC: 320 mg/L

Endpoint(s) effected: Mortality and abnormal effects

Reference 4

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

GLP compliance:

no

Duration:

24 h

Dose descriptor:

LC50

Effect conc.:

>= 580 - <= 880 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other:

Remarks:

D. magna

Key result

Duration:

48 h

Dose descriptor:

LC50

Effect conc.:

>= 440 - <= 880 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: D. magna

Details on results:

Effect range for D. magna is given from three tests. D. magna: arithmetic mean after 48 h exposure is given as 660 mg/L

Results with reference substance (positive control):

48-h LC50 values for NaCl averaged 1,042 mg/L: To determine whether the results of reference toxicant tests related to the responses observed in the concurrent exposures to ion combinations, LC50 values were calculated for the reference toxicant tests from the first 11 test groups with C. dubia (total of 1,045 ion solutions tested). During this period, 48-h LC50 values for NaCl averaged 1,042 mg/L as Cl2 with a coefficient of variation equal to 24%. The LC50 value from the concurrent reference toxicant test was included as an independent variable for each ion solution and thus considered by the stepwise logistic regression. In this analysis, the reference reference toxicant variable was not selected as being statistically significant, explaining only 0.12 % of the overall variance.From this, we surmised that there was no consistent relationship between the sensitivity of the test organisms (as measured by the reference toxicant test) and the responses of organisms in the concurrent ion exposures. For this reason, the reference toxicant test results were not considered further in subsequent regressions.

Reported statistics and error estimates:

Coefficients of variation for LC50 values for individual ion combinations were typical for acute toxicity tests, with means of 17 % for D. magna (SD = 7.5; range 4.8–31).

The measured ion concentrations in the stock solution differed less than 20 % from nominal concentrations and, thus, calculations are based on nominal values. To calculate ion concentrations in actual test solutions, the concentrations in the applicable stock solutions were multiplied by the relative proportion of each solution in the test solution. Because the dilution water (MHRW) also contained small concentrations of each ion, these background concentrations were then added to the calculated contributions from the stock solutions.

Validity criteria fulfilled:

not specified

Conclusions:

Within the framework of analysing statistical models to predict the toxicity of major ions to aquatic invertebrates and freshwater fish the toxicity of KCl to Daphnia manga was assessed. The study was conducted according to U.S. EPA national methods.

Executive summary:

The 48 -hr acute toxicity of KCl to Daphnia magna was studied under static conditions. Daphnids were exposed to control, positive control (NaCl), and appropriate nominal test chemical for 48 hours. Mortality was observed at test termination. The 48-hr LC₅₀ was determined at a mean of 660 mg/L.

Based on the results of this study, KCl would not be classified as toxic to D. magna in accordance with the CLP classification system.

This study is classified as acceptable for an acute toxicity study with freshwater invertebrates.

Results synopsis

Test organism age (e.g. 1^st instar): < 24 h

Test type: Static

LC₅₀: 660 mg/L

Endpoint(s) effected: Mortality

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reference 5

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Justification for type of information:

For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Reason / purpose for cross-reference:

read-across source

GLP compliance:

yes

Post exposure observation period:

None.

Reference substance (positive control):

no

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

10 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

10 g/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

behaviour

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

6 000 mg/L

Nominal / measured:

nominal

Conc. based on:

other: sodium L(-) lactate

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

6 000 mg/L

Nominal / measured:

nominal

Conc. based on:

other: sodium L(-) lactate

Basis for effect:

behaviour

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

5 850 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: sodium L(-) lactate

Basis for effect:

mobility

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

5 850 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

other: sodium L(-) lactate

Basis for effect:

behaviour

Details on results:

- Behavioural abnormalities: none
- Observations on body length and weight: not done
- Other biological observations: There were no immobile animals in the control vessels and in the solutions of 10,000 mg/L. The condition of the surviving animals was equal to that of the control animals (visually assessed). The NOEC for mobility and condition are therefore 10,000 mg/L based on the test material equal to 6000 mg sodium L(-) lactate/L. See Table 1 in 'Any other information on results incl. tables'.
- Mortality of control: no mortality in control
- Other adverse effects control: none
- Abnormal responses: none
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: none
- Effect concentrations exceeding solubility of substance in test medium: none

Validity criteria fulfilled:

yes

Conclusions:

No effects on mobility or behaviour were reported at concentrations as high as 6000 mg sodium L(-) lactate/L. Sodium L(-) lactate is not acutely toxic to Daphnia magna.

Executive summary:

The acute toxicity of sodium L(-) lactate to the freshwater crustacean Daphnia magna was determined as decribed in the OECD guideline no. 202 and according to the OECD principles of Good Laboratory Practice.

The test was carried out with 8 × 5 daphnias (eightfold test solutions) for the test concentration and control, and the test solutions were not replaced.

The exposure duration was 48 hours.

The nominal concentrations tested was 10,000 mg/L based on the test material, which equals 6000 mg/L sodium L(-) lactate.

At the start of the test the testsubstance appeared to be completely dissolved (visually assessed).

The actual concentration of sodium L(-) lactate in the test solutions was determined at the start and end of the test by measurement of the sodium concentration (ICP-AES). They were between 104 and 91 % of the nominal concentrations (average 97.5 %).

No effects of sodium L(-) lactate on mobility or condition of the daphnids were observed.

The results of the test were (in nominal concentrations):

48-h NOEC (mobility = 48-h EC₀): 6000 mg sodium L(-) lactate/L

48 -h NOEC (condition): 6000 mg sodium L(-) lactate/L

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Description of key information

Potassium lactate fully dissociates into K+ ions and lactate. The ecotoxicology of potassium-S-lactate can be understood in terms of the ecotoxicology of potassium chloride and lactic acid.

In short-term toxicity test on lactic acid in water fleas, immobilisation was observed resulting in estimated EC₅₀ values ranging between 130 and 750 mg/L (nominal) which can be attributed to a pH effect. Lactate as such is considered not to exert any systemic effects on daphnids in the tested concentration range of up to 750 mg/L.

Mount et al. (1997) published a peer-reviewed study on statistical models to predict the toxicity of several ionic compounds to Daphnia magna, including the substance KCl. The tests with daphnids referred to in the review article were conducted similar to the OECD test guideline 202. The EC₅₀ value after 48-h of static exposure derived for Daphnia magna is 660 mg/L.

Overall, effect values describing the potential toxicity of potassium-S-lactate are far beyond the limits relevant for classification and labelling. Re-calculated to potassium lactate, the above effect values would result in an EC₅₀ in excess of 1000 mg/L. Therefore, a key value for chemical safety assessment cannot be identified. Potassium-S-lactate is not hazardous for invertebrates.

Additional information

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.