Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Not applicable
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: meets generally accepted scientific standards, and acceptable for assessment. The reports presents of 4 tests, two of which are the final replicate experiments.
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Deviations:
yes
Remarks:
close vessels
Principles of method if other than guideline:
Not applicable
GLP compliance:
no
Specific details on test material used for the study:
Details on properties of test surrogate or analogue material (migrated information):Not applicable
Analytical monitoring:
no
Vehicle:
no
Details on test solutions:
The chemical was added at increasing concentrations from a test solution prepared from a continuously illuminated algae stock culture, prepared with nutrient solution, and was placed in front of a light wall. A single vessel was tested per concentration.
Test organisms (species):
Scenedesmus sp.
Details on test organisms:
No data
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Details on test conditions:
The investigations according to the guideline give false results in the case of volatile substances due to the decreasing concentration. Closing of the test vessel led to growth inhibition or death in the absence of the test material. By previous passage of CO2-enriched air and variation of the air space in the test vessel, the conditions could be optimized for the growth of the algae in the closed vessel during the 96 hour test so that the growth rate was comparable to that in an open vessel. The chemical was added at increasing concentrations from a test solution prepared from a continuously illuminated algae stock culture, prepared with nutrient solution, and was placed in front of a light wall. The test vessels were shaken slightly from time to time in order to prevent sedimentation of the algae.
Reference substance (positive control):
no
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
402 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
540 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
522 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Remarks:
(algae concentration)
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
609 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
cell number
Details on results:
Four tests were performed, two of which are replicate experiments (EC50=522mg/L and EC50=609 mg/L).
Results with reference substance (positive control):
Not applicable

Not applicable

Validity criteria fulfilled:
not specified
Conclusions:
The growth inhibition was assessed in 4 experiments, two of which are replicate experiments (EC50=522mg/L and EC50=609 mg/L).
Executive summary:

The effect on the growth of algae was investigated and the inhibition of microbial-degradation was studied. The substance concentrations found for 50% inhibition show that AMP 90 has a weak one. The values of the bacterial inhibition test were determined from the curves of the individual experiments through an average inhibition curve.

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1995-02-21 to 1995-04-06
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Guideline study with acceptable restrictions
Qualifier:
according to
Guideline:
EU Method C.3 (Algal Inhibition test)
GLP compliance:
yes
Analytical monitoring:
yes
Details on sampling:
- Concentrations:
stock solution / 70 / 120 / 200 / 360 / 600 / 1000 mg/L (test 1)
stock solution / 5 / 8 / 14 / 24 / 40 mg/L (test 2)
Vehicle:
no
Details on test solutions:
- Concentration of stock solution: 4.67 g/L test substance in deionized water (= 2 g dry residue/L)
Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Common name: Green algae
- Strain: Scenedesmus subspicatus (CHODAT (86.81 SAG))
- Source (laboratory, culture collection): Institut für Wasser-, Boden- und Lufthygiene, Berlin; subsequently in-house breeding
- Method of cultivation: in sterile-aerated Erlenmeyer flasks on light benches


ACCLIMATION
- Acclimation period: A preculture is withdrawn from a stock culture by tranfer 3 days prior to the beginning of the test from which preculture the test cultures are inoculated at a cell density of approximately 20 000 cells/ml.
- Culturing media and conditions (same as test or not): not mentioned
- Any deformed or abnormal cells observed: not mentioned
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h
Post exposure observation period:
none
Hardness:
Growth/test medium chemistry as described in guideline 92/69/EEC (C.3.), no further details mentioned
Test temperature:
21.5 - 22.3 °C (test 1)
21.4 - 22.3 °C (test 2)
pH:
test 1: 8.5 - 8.6 at the beginning of the test; 7.9 - 8.9 at the end of the test
test 2: 8.7 - 8.8 at the beginning of the test; 8.6 - 8.9 at the end of the test
Dissolved oxygen:
not mentioned
Salinity:
not mentioned
Nominal and measured concentrations:
test 1: 0 (control) / 70 / 120 / 200 / 360 / 600 / 1000 mg/L (nominal)
test 2: 0 (control) / 5 / 8 / 14 / 24 / 40 mg/L (nominal)
The test substance concentrations remained stable during the study (the geometric means of the analysed test substance concentrations measured after 0 and 72 hours differed < 20% from the nominal concentrations, see table below), therefore the nominal concentrations were used for evaluation.
Details on test conditions:
TEST SYSTEM
- Test vessel: sterile-aerated Erlenmeyes flasks
- Initial cells density: 2x10E4 cells/ml
- Control end cells density: x10E4 cells/ml
- No. of vessels per concentration (replicates): 5
- No. of vessels per control (replicates): 8
- No. of vessels per vehicle control (replicates): not applicable


GROWTH MEDIUM
- Standard medium used: yes


TEST MEDIUM / WATER PARAMETERS
no details mentioned


OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: not adjusted
- Photoperiod: not specified
- Light intensity and quality: approx. 8000 lux, white


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Cell numbers for exposure times of 24, 48, 72 h
- Determination of cell concentrations: The cell numbers were determined photometrically at a wavelenght of 685 nm
- Chlorophyll measurement: no
- Other: none


TEST CONCENTRATIONS
- Spacing factor for test concentrations: not mentioned
- Range finding study: no
Reference substance (positive control):
no
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
40 mg/L
Nominal / measured:
nominal
Conc. based on:
act. ingr.
Basis for effect:
biomass
Details on results:
- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): no observations made
- Any stimulation of growth found in any treatment: no
- Any observations (e.g. precipitation) that might cause a difference between measured and nominal values: no
- Effect concentrations exceeding solubility of substance in test medium: no

From the comparison of the areas under the growth curves resp. growth rate, the percentage inhibiton rates are calculated for each concentration (refer to control). The expect probits for each concentration were calculated by probit tranformation of the percentage inhibiton rates over the regression line. This probits are the basis for the following probit analysis according to Cavalli-Sforza (1972).
The NOEC value is determined on the basis of the cell growth during the whole exposure time, using the values of test 2.

Effective concentrations (dry residue) on the basis of cell growth:
EbC50 (72 h) = 150 mg/L
EbC10 (72 h) = 38 mg/L
EbC90 (72 h) = 587 mg/L
Effective concentrations (dry residue) based on the specific growth rate µ:
ErC50 (0-72 h) = 310 mg/L
ErC10 (0-72 h) = 85 mg/L
ErC90 (0-72 h): above highest tested concentration
Results with reference substance (positive control):
no reference substance tested
Reported statistics and error estimates:
Evaluation of the NOEC with the t-test: no significance, resp. values > control

Table #3: Cell density data (test 1)

 concentration

[mg/L]

 cell number (x 10E4 cells/mL) after        
  0 h   24 h  48 h  72 h
 control  2  6 20 61
 70  2  6  16  43
 120  2  5  13  31
 200  2  5  11  22
 360  2  4  7  12
 600  2  4  4  6
 1000  2  3  1  1

Table #4: Cell density data (test 2)

 concentration [mg/L] cell number (x 10E4 cells/mL) after          
   0 h  24 h  48 h  72 h
 control  2  6  17  63
 5  2  6  47  62
 8  2  6  19  69
 14  2  6  18  67
 24  2  6  18  67
 40  2  6  19  67

                                                                               

Table #5: Growth curves (test 1)

concentration [mg/L]   biomass (area under the growth curve) inhibition of biomass [%]   growth rate µ (0 - 72 h)  inhibition of growth rate [%]
 control 51.5   -  1.139  -
 70  38.5  25.2  1.023  10.2
 120  28.5  44.7  0.914  19.8
 200  22  57.3  0.799  29.9
 360  12  76.7  0.597  47.6
 600  6  88.3  0.366  67.9
 1000  -0.5  101  -0.231  120.3

Table #6: Growth curves (test 2)

concentration [mg/L]   biomass (area under the growth curve)  inhibition of biomass [%]  growth rate µ (0 - 72 h)  inhibition of growth rate[%]
 control  49.5  -  1.15  -
 5  49  1  1.145  0.4
 8  54.5  -10.1  1.18  -2.6
 14  52.5  -6.1  1.171  -1.8
 24  52.5  -6.1  1.171  -1.8
 40  53.5  -8.1  1.171  -1.8
Validity criteria fulfilled:
yes
Conclusions:
Effective concentrations (dry residue) on the basis of cell growth:
EbC50 (72 h) = 150 mg/L
EbC10 (72 h) = 38 mg/L
EbC90 (72 h) = 587 mg/L
NOEC (72 h) = 40 mg/mL
Effective concentrations (dry residue) based on the specific growth rate µ:
ErC50 (0-72 h) = 310 mg/L
ErC10 (0-72 h) = 85 mg/L

Description of key information

The algae study with AMP shows an EC50 of >= 522 mg/L for effects on biomass (no information on growth rate). The sodium salt of PTSA showed limited toxicity versus algae with an EC50 for growth rate of 310 mg/L.

For the substance the EC50 is set at 310 mg/L in a worst case assumption.

Key value for chemical safety assessment

EC50 for freshwater algae:
310 mg/L

Additional information

The rationale for read-across can be found in the document attached in section 13.