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
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Test procedure according to standard guideline with acceptable modifications (pH of test media not stated) (also assessed by OECD)
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Principles of method if other than guideline:
According to an OECD guideline 201: Alga, growth inhibition test (1984); modified
GLP compliance:
no
Analytical monitoring:
no
Vehicle:
yes
Details on test solutions:
Stock solutions prepared in acetone
Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
Algal inocula were obtained from actively growing axenic cultures of S. capricornatum, Cambridge Collection No. CCAP 278/4
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
120 h
Remarks on exposure duration:
LOEC values calculated at 72h
Post exposure observation period:
Not applicable
Hardness:
No data given
Test temperature:
22°C
pH:
No data given
Dissolved oxygen:
No data given
Salinity:
Not applicable
Nominal and measured concentrations:
0.05, 0.1, 0.5, 1.0 and 5.0 mg/l
Details on test conditions:
Tests conducted in Erlenmeyer flasks containing sterile culture medium, TPP added in acetone (<0.1ml/l medium).
Bolds basal medium (= BBM), OECD and EPA recommended media used in three separate tests
10E4 cells/ml
Reference substance (positive control):
no
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
0.5 - 5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.25 - 2.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
growth rate
Details on results:
BBM-Medium: 72 h-LOEC = 0.5 mg/l; OECD-Medium: 72 h-LOEC = 5 mg/l; US-EPA-Medium: 72 h-LOEC = 1 mg/l

Growth medium composition does affect the toxic values

obtained in standard algal toxicity tests. The observed
effects, however, were neither consistent nor predictable

Conclusions:
LOEC values of between 0.5 and 5.0 mg/l have been determined, depending on the culture medium used.
Executive summary:

A static study has been performed with S. capricornatum for TPP according to OECD guideline 201: Alga, growth inhibition test (1984); modified. The effect of three different media has been analyzed. After 72 h LOEC values between 0.5 and 5.0 mg/L have been determined, depending on the culture medium used.

Endpoint:
toxicity to aquatic algae and cyanobacteria
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: test procedure acc. to standard guideline with acceptable modifications (pH of test media not stated) (also assessed by OECD)
Qualifier:
according to
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
Principles of method if other than guideline:
According to OECD guideline 201: Alga, growth inhibition test (1984); modified
GLP compliance:
not specified
Analytical monitoring:
no
Vehicle:
yes
Details on test solutions:
Stock solutions prepared in acetone
Test organisms (species):
Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)
Details on test organisms:
Algal inocula were obtained from actively growing cultures of S. subspicatus, Cambridge Culture Collection No. CCAP 276/20
Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
120 h
Remarks on exposure duration:
LOEC values calculated at 72h
Post exposure observation period:
Not applicable
Hardness:
No data given
Test temperature:
22°C
pH:
No data given
Dissolved oxygen:
No data given
Salinity:
Not applicable
Nominal and measured concentrations:
0.05, 0.1, 0.5, 1.0 and 5.0mg/l
Details on test conditions:
Tests conducted in Erlenmeyer flasks containing sterile culture medium, TPP added in acetone (<0.1ml/l medium).
Bolds basal medium (= BBM), OECD and EPA recommended media used in three separate tests
10E4 cells/ml
Reference substance (positive control):
no
Duration:
72 h
Dose descriptor:
LOEC
Effect conc.:
0.5 - 5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: growth
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
0.25 - 2.5 mg/L
Nominal / measured:
nominal
Conc. based on:
test mat.
Basis for effect:
other: growth
Details on results:
BBM-Medium: 72 h-LOEC = 0.5 mg/l, OECD-Medium: 72 h-LOEC = 5 mg/l, US-EPA-Medium: 72 h-LOEC = 1 mg/l
Growth medium composition does affect the toxic values
obtained in standard algal toxicity tests. The observed
effects, however, were neither consistent nor predictable
Conclusions:
LOEC values of between 0.5 and 5.0mg/l have been determined, depending on the culture medium used.
NOEC values between 0.25 and 2.5mg/l have been derived using a standard procedure.
Executive summary:

A static study has been performed with S. subspicatus for TPP according to OECD guideline 201: Alga, growth inhibition test (1984); modified. The effect of three different culture media has been analyzed. After 72 h LOEC values of between 0.5 and 5.0 mg/L have been determined, depending on the culture medium used. NOEC values between 0.25 and 2.5mg/l have been derived using a standard procedure.

Description of key information

The most critical values were obtained for Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) and Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum) with LOECs between 0.5 and 5.0 mg/L depending on the growth medium.

Depending on this the most critical NOEC value of 0.25 mg/L has been derived using a standard procedure.

Key value for chemical safety assessment

EC10 or NOEC for freshwater algae:
0.25 mg/L

Additional information

The influence of varying growth medium compositions on the toxicity of the test substance was investigated for three algae species. The authors do not state NOEC values. Due to the only slight effect shown in the figures demonstrating the LOEC growth graphs compared to the control, derived NOECs are given for this test, using the procedure cited  in the Technical Guidance Document by the EU for Risk Assessments. There, LOEC values of 10 to 20 % effect are halved to derive a NOEC (LOEC/2 =  NOEC).