[No public or meaningful name is available]

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

Study period:

2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: Essai d’inhibition de la croissance des algues d’eau douce avec des algues vertes unicellulaires (Pseudokirchneriella subcapitata, NF EN ISO 8692, 2012

Principles of method if other than guideline:

The objective of this test is to determine the effects of the product tested on the growth of unicellular green algae after 72 h without change of medium (static test).
Algae of the species Pseudokirchneriella subcapitata, obtained from cultures in the exponential phase of growth, are placed in each of the concentrations of the sample to be tested as well as in the test medium (control).
After 72 h, the cell concentrations are determined in each concentration by microscopy (Malassez cell). The percentages of inhibition of the growth rate are then calculated relative to the average of the control tests.
The test takes place in two stages:
1) Screening test ("range-finding") in order to identify at least the concentrations of product tested which inhibit between 5% and 75% of the rate of algae growth, if possible Then
2) Complete test to determine if possible the CEr50-72h, CEr20-72h, CEr10-72h and the NOEC in mg / L of product.
Duration of the test: 72 h
Renewal of test solutions: none (static mode)
Test medium: ISO medium (composition in appendix 1).
Temperature: 21-25 ° C.
Illuminance: constant, daylight type (400-700 nm), approximately 7500 lux (55 microeinstein / m² / s).
Ventilation: none.
Agitation: constant, around 250 revolutions / min.
Initial cell concentration: approximately 104 cells per mL from a 3-4 day pre-culture.
Containers and test volume: 30 mL vials (20 mL test volume).

GLP compliance:

not specified

Remarks:

this test was not carried out initially to meet the REACH registration requirement, hence the fact that it is not carried out under GLP.

Test material

Test material information

Constituent 1

Reference substance name:

Dioctadecyl ether

Cas Number:

6297-03-6

Molecular formula:

C36H74O

IUPAC Name:

Dioctadecyl ether

Constituent 2

Reference substance name:

Dieicosyl ether

Cas Number:

502696-65-3

Molecular formula:

C40H82O

IUPAC Name:

Dieicosyl ether

Constituent 3

Reference substance name:

Didocosyl ether

Cas Number:

77456-42-9

Molecular formula:

C44H90O

IUPAC Name:

Didocosyl ether

Constituent 4

Reference substance name:

Methanesulphonic acid

EC Number:

200-898-6

EC Name:

Methanesulphonic acid

Cas Number:

75-75-2

Molecular formula:

CH4O3S

IUPAC Name:

methanesulphonic acid

Constituent 5

Reference substance name:

Octadecan-1-ol

EC Number:

204-017-6

EC Name:

Octadecan-1-ol

Cas Number:

112-92-5

Molecular formula:

C18H38O

IUPAC Name:

octadecan-1-ol

Constituent 6

Reference substance name:

Icosan-1-ol

EC Number:

211-119-4

EC Name:

Icosan-1-ol

Cas Number:

629-96-9

Molecular formula:

C20H42O

IUPAC Name:

icosan-1-ol

Constituent 7

Reference substance name:

Docosan-1-ol

EC Number:

211-546-6

EC Name:

Docosan-1-ol

Cas Number:

661-19-8

Molecular formula:

C22H46O

IUPAC Name:

docosan-1-ol

Constituent 8

Reference substance name:

betaine glycine mesylate

Molecular formula:

C6NO5

IUPAC Name:

betaine glycine mesylate

Constituent 9

Reference substance name:

Octadecyl betainate mesylate

Molecular formula:

C24NO4

IUPAC Name:

Octadecyl betainate mesylate

Constituent 10

Reference substance name:

Eicosyl betainate mesylate

Molecular formula:

C26NO4

IUPAC Name:

Eicosyl betainate mesylate

Constituent 11

Reference substance name:

Docosyl betainate mesylate

Cas Number:

Docosyl betainate mesylate

Molecular formula:

C28NO4

IUPAC Name:

Docosyl betainate mesylate

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

yes

Details on test solutions:

SFE: Solubilized fraction or forming a homogeneous suspension in water, obtained from a loading rate in mg / L of the product to be studied.
To prepare each ESF, a quantity of product to be studied is brought into contact with test medium at the load rate tested, in a closed container, with orbital agitation for 24 hours at approximately 110 rpm, at 20 ° +/- 2 ° C.
After shaking, the vials containing the loading levels are subjected to ultrasound for 1 minute. The aqueous fraction of each loading rate (FSE) is then recovered.
The SFE are used immediately for the performance of the test but the results are expressed as loading rate.

Test organisms

Test organisms (species):

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

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Test temperature:

21-25°C.

pH:

8.1 +/- 0.2

Nominal and measured concentrations:

Nominal: 100mg/L, 53mg/L, 31mg/L, 18mg/L, 11mg/L

Reference substance (positive control):

yes

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

ca. 31.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

EC20

Effect conc.:

ca. 15.9 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

ca. 10.8 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Effect concentrations 4

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

ca. 11 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat. (dissolved fraction)

Basis for effect:

growth rate

Results with reference substance (positive control):

Positive control: K2Cr2O7
EC50-72h = 0.99mg/L (to be valid, the value should be between 0.92 mg/L and 1.46mg/L)

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Executive summary:

The toxicity of the test item to aquatic algae was performed according to the French guideline:

"Essai d’inhibition de la croissance des algues d’eau douce avec des algues vertes unicellulaires (Pseudokirchneriella subcapitata, NF EN ISO 8692, 2012"

The results were the following:

EC50 72h=31.3mg/L

EC20 72h=15.9mg/L

EC10 72h=10.8mg/L

NOEC 72h=11mg/L