Amines, polyethylenepoly-

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08-05-1990 to 12-05-1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: study is complete, was performed under GLP. however due to the absence of chemcal analysis, the use in risk assessments is restricted, especially when looking at bioavailability.

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on test solutions:

For the definitive test a stock solution of 0.01 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
definitive test were selected.

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Details on test organisms:

The test was carried out with the unicellular green algae;
Selenastrurn capricornutum ATCC 22662. This strain was maintained
on mineral salts agar slants in the light at room temperature.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22.5-23 C

pH:

6.9-7.7

Nominal and measured concentrations:

nominal: 0, 0.080, 0.160, 0.320, 0.640, 1.280 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 nm.
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):

yes

Remarks:

pottassium dichromate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.23 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.16 mg/L

Nominal / measured:

nominal

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 higher ethylene polyamines are - 0.5 and
0.23 mg/litre respectively. The NOEC determined of higher ethylene polyamines is 0.16 mg/litre.

Results with reference substance (positive control):

Are in line with guideline requirements

Reported statistics and error estimates:

The ECSO 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 ECSO value calculated with the area
under the growth curve is termed EbC 50 (0-72 h) whereas the ECvalue calculated with the specific growth
rate is termed ErC50
Confidence limits were computed based on Fieller's theoreme All
computations were performed with the software package SAS
(release: 6.03).

Validity criteria fulfilled:

yes

Conclusions:

The ErC50 and EbC50 (0-72 h) of PEPA are 0.5 and 0.23 mg/litre respectively. The NOEC determined of
PEPA is 0.16 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 riskassessment when looking at the bio-available fraction

Executive summary:

The toxicity of PEPA 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.

- Preliminary 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 0.080, 0.160, 0.320, 0.640 and 1.280 mg/litre. The EbC50 (0 -72 h) and ErC50 of PEPA forS. capricornutumare 0.5 and 0.23 mg/litre, respectively. The NOEC determined of tetraethylenepentamine is 0.16 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.

Description of key information

 OECD guideline 201, Pseudokirchneriella subcapitata: EC50 (72 h) of 0.5 mg/L and NOEC (72 h): 0.16 mg/L based on algal growth rate   

Key value for chemical safety assessment

EC50 for freshwater algae:

0.5 mg/L

EC10 or NOEC for freshwater algae:

0.16 mg/L

Additional information

The acute toxicity of the substance to aquatic algae was tested in a study set up according to OECD guideline 201. The freshwater algae Pseudokirchneriella subcapitata was exposed to nominal substance concentrations of 0.080, 0.160, 0.320, 0.640 and 1.280 mg/L. Based on the algal growth rate an EC50 (72 h) of 0.5 mg/L (nominal) was determined. The NOEC (72 h) was 0.16 mg/L for algal growth and biomass respectively.