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Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Administrative data

toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
24-04-1990 to 28-04-1990
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study is complete, performed under GLP and valid. However no analysis was performed and thus the usability for risk assessment purposes is limited when assessing the bioavailable fraction.

Data source

Reference Type:
study report
Report Date:

Materials and methods

Test guideline
according to
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:

Test material

Test material form:
other: liquid
Details on test material:
- name: tetraethylenepentamine (TEPA)
- molecular weight: 189
- structural formula: H2N-(C2H4NH)4H
- CAS-reg. no.: 112-57-2
- purity: 97.3%
- identified impurities: TETA, PEHA
- appearance: pale yellow liquid
- water solubility: 20°C: completely miscible
- volatility: vapour pressure: <0.01 mbar
- storage: 20-40°C
- CRL code: T88-10-2.9

Sampling and analysis

Analytical monitoring:

Test solutions

Details on test solutions:
For the definitive test a stock solution of 0.10 g/litre was prepared by dissolving the test substance in deionized water.
This stock solution was titrated to a neutral pH. The selected test concentrations were prepared by dilution of this stock solution in the inoculated test medium. Based on the results of prelimanary experiments the nominal concentrations the definitive test were selected.

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
The test was carried out with the unicellular green algae; Selenastrum capricornutum ATCC 22662. This strain was maintained on mineral salts agar slants in the light at room temperature

Study design

Test type:
Water media type:
Limit test:
Total exposure duration:
72 h

Test conditions

Test temperature:
22-24 °C
Nominal and measured concentrations:
nominal: 0.5, 1.0, 2.0, 4.0, 8.0 mg/L
Details on test conditions:
The culturing apparatus is a cabinet in which the temperature is maintained between 22° and 24°C, and continuous uniform illumination is provided in the spectral range of 400 to 700 run. The light intensity is in the range of 6000 to 10000 lux which is obtained by using seven 30 W fluorescent lamps (colour temperature of approximately 4300 K), at a distance of 0.35 m from the algal culture. The culture flasks were rotated continuously at 100 rpm to prevent sedimentation of the algae.
Reference substance (positive control):
Potassium dichromate

Results and discussion

Effect concentrationsopen allclose all
72 h
Dose descriptor:
Effect conc.:
6.8 mg/L
Nominal / measured:
Conc. based on:
test mat.
Basis for effect:
growth rate
72 h
Dose descriptor:
Effect conc.:
2.1 mg/L
Nominal / measured:
Conc. based on:
test mat.
Basis for effect:
72 h
Dose descriptor:
Effect conc.:
0.5 mg/L
Nominal / measured:
Conc. based on:
test mat.
Basis for effect:
other: both growth rate and biomass
Details on results:
The ErC50 and EbC50 (0-72 h) of tetraethylenepentamine are 6.8 and 2.1 mg/litre respectively. The NOEC determined of tetraethylenepentamime is 0.50 mg/litre.
Reported statistics and error estimates:
The EC50 values were computed from the best fitted line (least square method) through the points given by the probit of the percentage inhibition and the logarithm of the concentration of the test substance. The EC50 value calculated with the area under the growth curve is termed EbC50 (0-72 h) whereas the EC50 value calculated with the specific growth rate is termed ErC50. Confidence limits were computed based on Fieller's theorem. All computations were performed with the software package SAS.

Applicant's summary and conclusion

Validity criteria fulfilled:
The ErC50 and EbC50 (0-72 h) of tetraethylenepentamine are 6.8 and 2.1 mg/litre respectively. The NOEC determined of tetraethylenepentamime is 0.50 mg/litre. The study was performed under GLP and meets all validity criteria. Only nominal test concentrations are presented which limits the use of this data when performing a risk assessment when looking at the bio-available fraction.
Executive summary:

The toxicity of tetraethylenepentamine to exponentially growing S. capricornutum has been assessed over an exposure period of 72 hours. The algal inhibition test was performed according to the EEC/OECD (201) test guidelines. One minor deviation from the protocol of the algal inhibition test was introduced.

- The KH2PO4 and NaCO3 concentrations in the test medium were increased to 160 and 100 mg/litre, respectively, to maintain a constant pH.

- Prelimanary experiments to determine the concentration range are performed but not reported according to the guidelines.

In the definitive test the algae were exposed to the following nominal concentrations of 0.500, 1.000, 2.000, 4.000 and 8.000 mg/litre. The EbC50 (0 -72 h) and ErC50 of tetraethylenepentamine for S. capricornutum are 2.1 and 0.8 mg/litre, respectively. The NOEC determined of tetraethylenepentamine is 0.50 mg/litre. All test concentrations are based on nominal. All validity criteria are met and thus the study is valid.

However the usability of the presented data islimited due to the absence of actual measured concentrations and therefore no information on the bioavailable fraction.