Calcium 4-chloro-2-(5-hydroxy-3-methyl-1-(3-sulfonatophenyl)pyrazol-4-ylazo)-5-methylbenzenesulfonate

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study according to OECD Guideline No. 201 and GLP

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

- Sampling method: samples were diluted 1:20 with mobile phase and analysed.
- Sample storage conditions before analysis: all samples were stored at 7 ± 2°C until start of analysis

Vehicle:

no

Details on test solutions:

PREPARATION OF TEST SOLUTION
A saturated solution was used as limit concentration based on the results of a range finding test. A dispersion of 53 mg/L, prepared in dilution water, was intensively stirred(20500 rpm) for 5 min and membrane filtrated with 0.45µm (RC55, S&S 10410214).
Limit concentration measured: 39.8 mg/L (mean)

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Strain: Desmodesmus subspicatus CHODAT SAG 86.81
- Source (laboratory, culture collection): Sammlung von Algenkulturen (SAG), Pflanzenphysiologisches Institut der Universität Göttingen, Göttingen, Germany
- Age of inoculum (at test initiation): four day-old preculture
- Method of cultivation: Fresh stocks were prepared every month on Z-Agar. Light intensity amounted 35-70 μE·m-2·s-1 for 24 h per day.

ACCLIMATION
- Acclimation period: four days, see above
- Culturing media and conditions (same as test or not): preculture incubated in 500 mL Erlenmeyer flasks; all algae were from the same source.
- Any deformed or abnormal cells observed: no

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test temperature:

22-23 (mean: 22.5) °C

pH:

Start: 8.09 (test solution), 8.33 (control)
End, 72 h: 9.01 (test solution), 9.14 (control)

Nominal and measured concentrations:

A limit test with a saturated solution 39.8 mg/L (mean) was carried out.
Measured concentrations: test start 39.4 mg/L, test end 40.1 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: Sterile erlenmeyer flasks, volume: 250 mL
- Test volume: 100 mL
- Initial cells density: appr. 10000 cells/mL
- Control end cells density: 1196245 (mean from 6 replicates) cells/mL
- No. of vessels per limit concentration (replicates): 3
- No. of vessels per control (replicates): 6

GROWTH MEDIUM
- Standard medium used: yes

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: dilution water according to guidelines
- Intervals of water quality measurement: at the start and at the end (72 h)

OTHER TEST CONDITIONS
- Sterile test conditions: yes (sterile erlenmeyer flasks were used)
- Photoperiod: 24 h/d light
- Light intensity and quality: min. 60.8, max. 72.4 (mean 68.1 μE·m-2·s-1)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: counting in a plankton chamber
- Other: measurements at the beginning of the test (after application) and every 24 h, filtrated culture medium was used as ground signal. Each replicate was measured 6-fold.

TEST CONCENTRATIONS
- Test concentrations: 39.8 mg/L
- Spacing factor for test concentrations: only one concentration (saturated solution), limit test
- Justification for using less concentrations than requested by guideline: limit test

Reference substance (positive control):

yes

Remarks:

Potassium dichromate p.a.

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 39.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: not applicable

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 39.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: not applicable

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

39.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: biomass and growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 39.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: biomass and growth rate

Details on results:

NOEC, LOEC and EC50 values for Inhibition of biomass growth and rate-related inhibition.

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no

Environmental conditions, pH-value, measured at 0 and 72 h, and room temperature, measured continuously, met the validity criteria of the guideline.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50 (biomass growth): 0.29 mg/L (0-72 h), 95 % confidence interval: 0.26-0.33 mg/l
- EC50 (rate-related inhibition): 0.59 mg/L (0-72 h), 95 % confidence interval: 0.55-0.63 mg/l

Reported statistics and error estimates:

The NOEC and LOEC were determined by calculation of statistical significance of biomass integrals and growth rates. One Way Analysis of Variance (ANOVA) and DUNNETT’s test was carried out for the determination of statistically significant differences compared to control replicates. When running a One Way Analysis of Variance a Normality Test and an Equal Variance Test were done first. P-values for both Normality and Equal Variance Tests were 0.05. The α-value for ANOVA was α=0.05.

Validity criteria fulfilled:

yes

Conclusions:

No inhibiting effects on biomass growth and specific growth rate were found in the saturated solution. The EC50-values for inhibition of biomass growth (EbC50) and specific growth rate (ErC50) after 72 h were > 39.8 mg/L (mean).

Executive summary:

The toxicity of Pigment Yellow 191 to the unicellular freshwater green alga Desmodesmus subspicatus was determined according to the principles of OECD-Guideline 201. The aim of the study was to assess the effects on growth rate and biomass production over a period of 72 h. The study was conducted under static conditions with an initial cell density of appr. 10000 cells/mL. A limit test with a saturated solution was carried out. A solution of 39.8 mg/L test item was prepared. The limit concentration was measured at the beginning and the end of the study. Three replicates were tested for the saturated solution and 6 replicates for the control. Environmental conditions, pH-value and room temperature, were determined to be within the acceptable limits. All effect values are based on the saturated solution of the test item.

In this study the test item did not cause any inhibiting effects to Desmodesmus subspicatus after 72 h when tested with a 39.8 mg/L solution.

Reference 2

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

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

Adequacy of study:

key study

Reason / purpose for cross-reference:

read-across source

GLP compliance:

yes

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 39.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: not applicable

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 39.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: not applicable

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

39.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: biomass and growth rate

Duration:

72 h

Dose descriptor:

LOEC

Effect conc.:

> 39.8 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: biomass and growth rate

Details on results:

NOEC, LOEC and EC50 values for Inhibition of biomass growth and rate-related inhibition.

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no

Environmental conditions, pH-value, measured at 0 and 72 h, and room temperature, measured continuously, met the validity criteria of the guideline.

Results with reference substance (positive control):

- Results with reference substance valid? yes
- EC50 (biomass growth): 0.29 mg/L (0-72 h), 95 % confidence interval: 0.26-0.33 mg/l
- EC50 (rate-related inhibition): 0.59 mg/L (0-72 h), 95 % confidence interval: 0.55-0.63 mg/l

Reported statistics and error estimates:

The NOEC and LOEC were determined by calculation of statistical significance of biomass integrals and growth rates. One Way Analysis of Variance (ANOVA) and DUNNETT’s test was carried out for the determination of statistically significant differences compared to control replicates. When running a One Way Analysis of Variance a Normality Test and an Equal Variance Test were done first. P-values for both Normality and Equal Variance Tests were 0.05. The α-value for ANOVA was α=0.05.

Validity criteria fulfilled:

yes

Conclusions:

No inhibiting effects on biomass growth and specific growth rate were found in the saturated solution. The EC50-values for inhibition of biomass growth (EbC50) and specific growth rate (ErC50) after 72 h were > 39.8 mg/L (mean).

Executive summary:

The toxicity of Pigment Yellow 191 to the unicellular freshwater green alga Desmodesmus subspicatus was determined according to the principles of OECD-Guideline 201. The aim of the study was to assess the effects on growth rate and biomass production over a period of 72 h. The study was conducted under static conditions with an initial cell density of appr. 10000 cells/mL. A limit test with a saturated solution was carried out. A solution of 39.8 mg/L test item was prepared. The limit concentration was measured at the beginning and the end of the study. Three replicates were tested for the saturated solution and 6 replicates for the control. Environmental conditions, pH-value and room temperature, were determined to be within the acceptable limits. All effect values are based on the saturated solution of the test item.

In this study the test item did not cause any inhibiting effects to Desmodesmus subspicatus after 72 h when tested with a 39.8 mg/L solution.

Description of key information

     The toxicity of Pigment Yellow 191 to the unicellular freshwater green alga Desmodesmus subspicatus was determined according to the principles of OECD-Guideline 201. The aim of the study was to assess the effects on growth rate and biomass production over a period of 72 h. The study was conducted under static conditions with an initial cell density of approximately 10000 cells/mL. A limit test with a saturated solution was carried out. A solution of 39.8 mg/L test item was prepared. The limit concentration was measured at the beginning and the end of the study. Three replicates were tested for the saturated solution and 6 replicates for the control. Environmental conditions, pH-value and room temperature, were determined to be within the acceptable limits. All effect values are based on the saturated solution of the test item.
    
    
    
    

No inhibiting effects on biomass growth and specific growth rate were found in the saturated solution. The EC50-values for inhibition of biomass growth (EbC50) and specific growth rate (ErC50) after 72 h were > 39.8 mg/L (mean).












    
  
  
  
  

he toxicity of Pigment Yellow 191 to the unicellular freshwater green alga Desmodesmus subspicatus was determined according to the principles of OECD-Guideline 201. The aim of the study was to assess the effects on growth rate and biomass production over a period of 72 h. The study was conducted under static conditions with an initial cell density of approximately 10000 cells/mL. A limit test with a saturated solution was carried out. A solution of 39.8 mg/L test item was prepared. The limit concentration was measured at the beginning and the end of the study. Three replicates were tested for the saturated solution and 6 replicates for the control. Environmental conditions, pH-value and room temperature, were determined to be within the acceptable limits. All effect values are based on the saturated solution of the test item.














  




No inhibiting effects on biomass growth and specific growth rate were found in the saturated solution. The EC50-values for inhibition of biomass growth (EbC50) and specific growth rate (ErC50) after 72 h were > 39.8 mg/L (mean).



















 















    





he toxicity of Pigment Yellow 191 to the unicellular freshwater green alga Desmodesmus subspicatus was determined according to the principles of OECD-Guideline 201. The aim of the study was to assess the effects on growth rate and biomass production over a period of 72 h. The study was conducted under static conditions with an initial cell density of approximately 10000 cells/mL. A limit test with a saturated solution was carried out. A solution of 39.8 mg/L test item was prepared. The limit concentration was measured at the beginning and the end of the study. Three replicates were tested for the saturated solution and 6 replicates for the control. Environmental conditions, pH-value and room temperature, were determined to be within the acceptable limits. All effect values are based on the saturated solution of the test item.

















  





No inhibiting effects on biomass growth and specific growth rate were found in the saturated solution. The EC50-values for inhibition of biomass growth (EbC50) and specific growth rate (ErC50) after 72 h were > 39.8 mg/L (mean).























 


















    






he toxicity of Pigment Yellow 191 to the unicellular freshwater green alga Desmodesmus subspicatus was determined according to the principles of OECD-Guideline 201. The aim of the study was to assess the effects on growth rate and biomass production over a period of 72 h. The study was conducted under static conditions with an initial cell density of approximately 10000 cells/mL. A limit test with a saturated solution was carried out. A solution of 39.8 mg/L test item was prepared. The limit concentration was measured at the beginning and the end of the study. Three replicates were tested for the saturated solution and 6 replicates for the control. Environmental conditions, pH-value and room temperature, were determined to be within the acceptable limits. All effect values are based on the saturated solution of the test item.




















  






No inhibiting effects on biomass growth and specific growth rate were found in the saturated solution. The EC50-values for inhibition of biomass growth (EbC50) and specific growth rate (ErC50) after 72 h were > 39.8 mg/L (mean).



























 

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:

39.8 mg/L