Dioleamide

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Remarks:

The Department of Health of the Government of the United Kingdom

Test material

Reference

Name:

Unnamed

Type:

Constituent

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: A stock solution was prepared by adding 550 mg test substance to 11 L culture medium. The substance was dispersed by stirring (1500 rpm) for 24 hours. The mixture was then filtered (0.2 μm Gelman Acrocap filter). To 1 L of the stock solution (100% v/v saturated solution) 7.6 mL of algal suspension were added.

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Strain: CCAP 278/4
- Source: Culture Collection of Algae and Protozoa (CCAP), SAMS Research Services Ltd, Scottish Marine Institute, Oban, Argyll, Scotland


ACCLIMATION
- Culturing media and conditions: same as in test

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Test temperature:

24 ± 1 ºC

pH:

7.9 - 8.1

Nominal and measured concentrations:

Nominal substance concentration: 100% v/v saturated solution

Details on test conditions:

TEST SYSTEM
- Test vessel: conical flasks
- Material, size, fill volume: glass, 250 mL nominal, 100 mL fill volume
- Initial cells density: 5000 cells/mL
- No. of vessels per concentration (replicates): 6
- No. of vessels per control (replicates): 6

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: The culture medium was prepared using reverse osmosis purified deionized water* and the pH adjusted to 7.5 ± 0.1 with 0.1N NaOH or HCl.
- Intervals of water quality measurement: at test start and test termination

OTHER TEST CONDITIONS
- Photoperiod: continuous illumination
- Light intensity and quality: approx. 7000 lux, warm white lighting (380 – 730 nm)


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: cell density after 0, 25, 49 and 72 hours (Coulter® Multisizer Particle Counter)


TEST CONCENTRATIONS
- Range finding study
- Test concentrations: 1.0, 10 and 100% v/v
- Results used to determine the conditions for the definitive study: no effects observed at any of the tested concentrations

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

100 other: % v/v saturated solution

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 other: % v/v saturated solution

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

- Exponential growth in the control (for algal test): yes
- Observation of abnormalities (for algal test): none

Results with reference substance (positive control):

ErC50 (72 h): 1.1 mg/L; NOEC (72 h): 0.50 mg/L

Reported statistics and error estimates:

Growth rate and yield data were analysed using a Student’s t-test incorporating Bartlett's test for homogeneity of variance (Sokal and Rohlf, 1981; SAS, 1999 - 2001).

Any other information on results incl. tables

The test substance concentration was analysed for verification of test concentrations at 0 and 72 hours by HPLC-MS-MS (Perkin Elmer, API 3000; triple stage quadrupole mass spectrometer). The test concentration at 0 hours was below the limit of quantitation (LOQ= 0.014 mg/L). At 72 hours a test concentration of 0.015 mg/L was measured.

Applicant's summary and conclusion

Conclusions:

The read across source substance did not show any toxicity at the saturation concentration. This experimental result confirms the QSAR prediction for the target substance also predicting no toxicity to algae at the solubility limit.