Propane-1,3-diyl bis(4-aminobenzoate)

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:

2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

GLP compliance:

yes

Analytical monitoring:

yes

Details on sampling:

Chemical analysis of the test item concentrations in the test solutions was performed to determine
exposure concentration and stability of the test item during exposure. Substance-specific analysis
was performed at the test site menal GmbH.
After 0 h, 24 h, 48 h and 72 h exposure, both additional vessels of NC, A, B, C, D and E were
sampled; one sample per replicate: 2 samples of 5 mL per treatment group. The samples were
filled into 12 mL glass vials. To each vial, 5 mL acetonitrile was added and samples were stored in
the freezer (≤ -18 °C).
Of each sampled treatment, one of the analytic samples from 0 h, 24 h, 48 h and 72 h was sent to
the analytical laboratory at the test site menal GmbH for chemical analysis. The remaining samples
were stored as retain samples in the freezer (≤ -18 °C) until finalisation of the study.

Vehicle:

no

Test organisms (species):

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

Details on test organisms:

The test organism Raphidocelis subcapitata (Strain No. 61.81 SAG) originates from the Culture
Collection of Algae at the University of Goettingen and was cultivated in suspension culture. The
strain used for this study has been cultured at Hydrotox GmbH since July 2017. Twice a week, the
stock suspension is inoculated into fresh Holm-Hansen medium (composition: 496 mg/L NaNO3,
39 mg/L K2HPO4, 75 mg/L MgSO4×7H2O, 36 mg/L CaCl2×2H2O, 58 mg/L Na2CO3, 10 mg/L
Na2EDTA×2H2O, 3 mg/L citric acid, 3 mg/L iron citrate, 0.1144 mg/L H3BO3, 0.0724 mg/L MnCl2×
4H2O, 0.0088 mg/L ZnSO4×7H2O, 0.0032 mg/L CuSO4×5H2O, 0.0010 mg/L Na2MoO4×2H2O,
0.0016 mg/L CoCl2×6H2O) under axenic conditions to keep it in exponential growth.

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Details on test conditions:

The test vessels are sealed with cellulose stoppers and kept in the light incubator (specified
temperature: 21 – 24 °C, constant within ± 2 °C). They are placed on the shaking table with adhesive
mats and continuously shaken with 100 rpm and an orbital diameter of 5 cm.
The test vessels were permanent illuminated by LEDs (warm white) with a light intensity of 88.5 μE m
² s-1 ± 8.0 %. The pH was measured at the start (0 h) and at the end (72 h) of the test.

Reference substance (positive control):

no

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.019 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: yield

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

3.501 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

other: yield

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

0.159 mg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Validity criteria fulfilled:

yes

Conclusions:

EC50 (Yield, 72 h): 0.019 mg/L, 95 % Confidence Limit (CL): 0.007 – 0.053 mg/L
EC50 (Growth rate, 72 h): 3.501 mg/L, 95 % Confidence Limit (CL): 0.627 – 18.398

EC10 (Yield, 72 h): 0.0 mg/L (n.d.), 95 % Confidence Limit (CL): 0.000 – 0.000 mg/L
EC10 (Growth rate, 72 h): 0.159 mg/L, 95 % Confidence Limit (CL): 0.040 – 0.625 mg/L

Executive summary:

EC50 (Yield, 72 h): 0.019 mg/L, 95 % Confidence Limit (CL):  0.007 – 0.053 mg/L

EC50  (Growth rate, 72 h): 3.501 mg/L,  95 % Confidence Limit (CL): 0.627 – 18.398

EC10 (Yield, 72 h): 0.0 mg/L (n.d.), 95 % Confidence Limit (CL):  0.000 – 0.000 mg/L

EC10 (Growth rate, 72 h): 0.159 mg/L, 95 % Confidence Limit (CL):  0.040 – 0.625 mg/L

Description of key information

95 % Confidence Limits (CL) Yield (72 h) Growth rate (72 h)

EC50 (Yield, 72 h): 0.019 mg/L, 95 % Confidence Limit (CL):  0.007 – 0.053 mg/L

EC50  (Growth rate, 72 h): 3.501 mg/L,  95 % Confidence Limit (CL): 0.627 – 18.398

EC10 (Yield, 72 h): 0.0 mg/L (n.d.), 95 % Confidence Limit (CL):  0.000 – 0.000 mg/L

EC10 (Growth rate, 72 h): 0.159 mg/L, 95 % Confidence Limit (CL):  0.040 – 0.625 mg/L

Key value for chemical safety assessment

EC50 for freshwater algae:

3.501 mg/L

EC10 or NOEC for freshwater algae:

0.159 mg/L