Pyridinium, 1-[4-[[4-[2-[5-(acetylamino)-2-methoxy-4-[2-(3,6,8-trisulfo-2-naphthalenyl)diazenyl]phenyl]diazenyl]-8-sulfo-1-naphthalenyl]amino]-6-amino-1,3,5-triazin-2-yl]-3-carboxy-, inner salt, sodium salt (1:?)

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:

guideline study

Data source

Reference

Reference Type:

other company data

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

Test material

Test material information

Constituent 1

Reference substance name:

Pyridinium, 1-[4-[[4-[2-[5-(acetylamino)-2-methoxy-4-[2-(3,6,8-trisulfo-2-naphthalenyl)diazenyl]phenyl]diazenyl]-8-sulfo-1-naphthalenyl]amino]-6-amino-1,3,5-triazin-2-yl]-3-carboxy-, inner salt, sodium salt (1:?)

EC Number:

691-442-9

Cas Number:

1316184-44-7

Molecular formula:

C38H29N11O16S4 . x Na x=1~4

IUPAC Name:

Pyridinium, 1-[4-[[4-[2-[5-(acetylamino)-2-methoxy-4-[2-(3,6,8-trisulfo-2-naphthalenyl)diazenyl]phenyl]diazenyl]-8-sulfo-1-naphthalenyl]amino]-6-amino-1,3,5-triazin-2-yl]-3-carboxy-, inner salt, sodium salt (1:?)

Test solutions

Details on test solutions:

The standard test procedures required generation of test solutions, which contained completely dissolved test substance concentrations or stable and homogeneous mixtures or dispersions. The testing of concentrations that would disturb the test system was prevented as much as possible (e.g. film of the test substance on the water surface.)
Preparation of test solutions started with a concentration of 100 mg/l. No other treatment than vigorous shaking was needed to completely dissolve the test substance in the medium. The lower test concentrations for the range-finding test were prepared by subsequent dilutions of the highest concentration in test medium. The final test solutions ranged from clear and colourless to clear and dark red.

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchnerella subcapitata
- Strain: NiVA CHL 1
- Source (laboratory, culture collection): In-house laboratory culture.
- Method of cultivation:Algae stock cultures were started by inoculating growth medium with algal cells from a pure culture on agar. The suspensions were continuously aerated and exposed to light in a climate room at a temperature of 21-24℃.
ACCLIMATION
- Acclimation period: 3 days before the start of the test, cells from the algal stock culture were inoculated in culture medium at a cell density of 1 x 10E4 cells/ml. The pre-culture was maintained under the same conditions as used in the test. The cell density was measured immediately before use.

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Post exposure observation period:

at t=0 h, t=24 h and t=72 h

Test conditions

Hardness:

24 mg CaCO3/L

Test temperature:

21-24℃

pH:

8.1

Nominal and measured concentrations:

0.1, 1, 10 and 100 mg/l

Reference substance (positive control):

yes

Remarks:

potassium dichromate

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

meas. (TWA)

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC10

Effect conc.:

100 mg/L

Nominal / measured:

meas. (TWA)

Basis for effect:

growth rate

Results with reference substance (positive control):

Potassium dichromate reduced growth rate of this fresh water algae species at nominal concentrations of 0.56 mg/l and higher.

The EC50 for growth rate reduction (ERC50: 0-72h) was 2.3 mg/l with a 95% confidence interval ranging from 1.9 to 2.9 mg/l. The historical ranges for growth rate reduction lie between 0.82 and 2.3 mg/l. Hence, the ERC50: 0-72h for the algal culture tested corresponds with this range.

The EC50 for yield inhibition (EYC50: 0-72h) was 0.90 mg/l with a 95% confidence interval ranging from 0.68 to 1.2 mg/l. The historical ranges of the 72h EC50 for yield inhibition lie between 0.43 and 1.1 mg/l. Hence, the EYC50: 0-72h for the algal culture tested corresponds with this range.

Any other information on results incl. tables

Effect parameters

Parameter	Concentration Everzol SB45 (mg/l)
72h-ERC10	100
72h-ERC50	>100
72h-EYC50	>100

       

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of the present study with Pseudokirchneriella subcapitata, no reduction of growth rate was recorded at the limit concentration being 100 mg Everzol SB45 per litre.

The EC50 for growth rate reduction (72h-ERC50) and the EC50 for yield inhibition (72h-EYC50) were beyond the range tested, i.e. exceeded an analytically confirmed nominal concentration of 100 mg/l.

The EC10 for growth rate reduction (72h-ERC10) approximated an analytically confirmed nominal concentration of 100 mg/l.