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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

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Administrative data

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
migrated information: read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP Guideline study with restrictions
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2002
Report Date:
2002

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Tallowalkylamine

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: stock solution (20 mg/L) was prepared with natural river water. Dispersion carried out with: 30 min ultrasound at 40 °C

Test organisms

Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
TEST ORGANISM
- Common name: Green algae
- Strain: Desmodesmus subspicatus CHODAT SAG 86.81
- Source: The algae culture was optained from the Institut of plant physiology, University of Göttingen, Germany;
- Method of cultivation: Fresh stock solutions were prepared every month on Z-agar. Light intensity amounted 35-70 µE/m²

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
72 h

Test conditions

Hardness:
91.3 mg CO3/L
Test temperature:
23 ± 2 °C
pH:
8.06 - 8.23
Nominal and measured concentrations:
Nominal concentrations: control, 0.125, 0.25, 0.5, 1, 2 and 4 mg/L
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Material, size, fill volume: 250 mL-Erlenmayer-flasks with 100 mL test volume
- No. of vessels per 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: A natural river water of agricultural backround, middle reach of the river "Böhme", Lower-Saxony was used.
Test water parameter:
pH: 8.2
Conductivity [μS/cm]: 397
DOC [mg C/L]: 7.3
TOC [mg C/L]: 9.9
Ammonium-N [mg N/L]: 0.141
Nitrate-N [mg N/L]: 2.38
o-Phosphate-P [mg P/L]: 0.031
Total Phosphate [mg P/L]: 0.128
Suspended Matter [mg/L]: 17.4
Total Hardness [mg CO3/L]: 91.3
- Culture medium different from test medium: yes
- Intervals of water quality measurement: cell density was measured every 24 hours. Temperature was measured permanently and the pH value was determinated at the beginning and the end of the test.


OTHER TEST CONDITIONS
- Photoperiod: Permanent illumination (24h)
- Light intensity and quality: 60-120 µE/m²*s



EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: fluorimeter and microscopic evaluation
Reference substance (positive control):
yes
Remarks:
potassium dicromate

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
0.39 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.125 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
0.25 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
0.31 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.125 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
0.25 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
biomass

Any other information on results incl. tables

After 72 h algae were transferred from the nominal dosage levels 0.5 -4 mg/L to fresh untreated medium and allowed to grow for further 4 - 6 days under test conditions. The test item effect was observed to be reversible at these concentration levels.

Table 1: Concentration of the test item:

Nominal test item conc.

[mg/L]

 

Meas. conc. [mg/L]after 0 h

Meas. conc. [mg/L]after 3 d

20.00

14.4

8.9

4.00

(11.5)

3.7

Control

< detection limit

< detection limit

Applicant's summary and conclusion

Conclusions:
In this study Tallowalkylamine was found to inhibit the growth of the freshwater green alga Desmodesmus subspicatus at concentrations > 0.25 mg/L (biomass growth and growth rate). The EC50 values with 95 % confidence intervals for inhibition of biomass growth (EbC50) and specific grothw rate (ErC50) after 72h were 0.31 (0.30 - 0.32) and 0.39 (0.38 - 0.41) mg/L, respectively.
Inhibition effects were found to be reversible up to 4 mg/L (all effect levels are given as nominal concentrations)
Executive summary:

The toxicity of Tallowalkylamine (batch 2410202) to the unicellular freshwater green alga Desmodesmus subspicatus was determined according to the principles of OECD-Guideline 201 (1984), at DR.U.NOACK-LABORATORIUM FÜR ANGEWANDTE BioLoGIE in 31157 Sarstedt, Germany from June 3 to 6, 2002 for the determination of the NOEC and EC of growth rate and biomass production over a period of 72 h.

Natural water from the river “Böhme“ was used as test medium. Sampling site and water parameters are listed in part 3 (test medium). The chosen water originated from a predominantly agricultural region. From a limnological point of view this sampling site represents typical conditions for a river of this classification (middle reach).

The river water enabled the increase of cell density more than 16-fold when incubated for 72 h.

The study was conducted under static conditions with an initial cell density of nominally cells/mL. 6 concentration levels were tested in a geometrical series with a dilution factor of

2:

nominal: 0.125 - 0.25 - 0.5 - 1 -2-4 mg/L

Three replicates were tested for each concentration level and 6 replicates for control. The test item was clearly dissolved throughout the test Microscopic evaluation of the cells at the start of the incubation period revealed no morphological abnormalities. Water quality parameters of pH value, measured at 0 and 72 h, and room temperature, measured continuously, were determined to be within the acceptable limits.

The highest tested concentration, the stock solution and the control were analytically verified via GC/MS analysis. The test item concentration had decreased at the end of the test. Biotic degradation of Tallowalkylamine is not regarded to be the reason for the decrease of the test item concentration. The natural river water used for the preparation of the test media has been frozen for at least 14 days to reduce microbial activity (see page 12 of the report). Therefore a biological degradation of Tallowalkylamine seems to be unlikely, The most probable reason for the decrease or incomplete recovery of test item concentrations during the test is adsorption on particulate matter and humic acids. The results are therefore based an nominal concentrations representing the total exposure concentration (dissolved and adsorbed). The variation in the recovery rates are most likely caused by small differences in the concentration of suspended matter. The results of the study showed a clear dose response relationship with respect to the rate related inhibition and the inhibition of biomass growth. Therefore it can be suggested that the test item concentrations in the lower dosage levels met the nominal values when being prepared freshly.

Details are given in part 10. All effect levels are given based on nominal concentrations.

inhibition of biomass growth [mg/L]
EbC50 0.31
95% confidence interval 0.30 - 0.32
LOEC 0.25
NOEC 0.125
rate-related inhibition [mg/L]
ErC50 0.39
95% confidence interval 0.38 - 0.41
LOEC 0.25
NOEC 0.125

After 72 h algae were transferred from the nominal dosage levels 0.5 - 4 mg/L to fresh untreated medium and allowed to grow for further 4 to 6 d under test conditions. The test item effect was observed to be reversible at these concentration levels.