C.I. Pigment Violet 55

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:

2015

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Nominal concentrations (WAF method) - because sensitive analytical method could not be developed.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Reaction mass of 2,9-dimethoxy-5,12-dihydroquino[2,3-b]acridine-7,14-dione and 2,9-dichloro-5,12-dihydroquino[2,3-b]acridine-7,14-dione

EC Number:

941-220-5

Cas Number:

1126076-86-5

Molecular formula:

PV54: C22H16N2O4 PR202: C20H10Cl2N2O2

IUPAC Name:

Reaction mass of 2,9-dimethoxy-5,12-dihydroquino[2,3-b]acridine-7,14-dione and 2,9-dichloro-5,12-dihydroquino[2,3-b]acridine-7,14-dione

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Sampling and analysis

Analytical monitoring:

no

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

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

Study design

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

EL50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: WAF prepared at the given loading rate

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The EL50 for inhibition of both growth rate (72h-ERL50) and yield (72h-EYL50) was above 100 mg/l.

Executive summary:

Pseudokirchneriella subcapitata, Fresh Water Algal Growth Inhibition Test with C. I. Pigment Violet 55.

 

The study procedures described in this report were based on the OECD guideline No. 201, 2006; Annex 5 corrected 28 July 2011. In addition, the procedures were designed to meet the test methods of theCommissionRegulation (EC) No 440/2008, Part C.3, 2008; Amended by EC No. 761/2009and the OECD series on testing and assessment number 23, 2000.

 

The batch of C. I. Pigment Violet 55 tested was a violet powder and not completely soluble in test medium at the initial loading rates prepared.No correction was made for the purity/composition of the test substance.

 

Preparation of test solutions started with loading rates of 1.0, 10 and 100 mg/l applying two days of magnetic stirring to reach the maximum solubility of the test substance in the test medium. The resulting aqueous mixtures were filtered through a 0.45 µm membrane filter and the Water Accommodated Fractions (WAFs) were used as test concentrations.The WAF prepared at a loading rate of 1.0 mg/l was observed to be clear and colourless. The WAFs prepared at loading rates of 10 and 100 mg/l were observed to be clear and slightly purple.

 

A combined limit/range-finding test was performed.Six replicates of exponentially growing algal cultures were exposed to a control and to a WAF prepared at a loading rate of 100 mg/l. In addition, three replicates per group were exposed toWAFs prepared at loading rates of 1.0 and 10 mg/l. The initial cell density was 10⁴cells/ml and the total exposure period was 72 hours. The study did not include sampling for determination of actual exposure concentrations.

 

From 48 hours of exposure onwards test substance particles were observed in the WAFs prepared at 10 and 100 mg/l. In addition, after 72 hours of exposure a floating layer was observed at both WAFs. Test concentration in these two WAFs were therefore above the solubility limit in test medium.

 

The study met the acceptability criteria prescribed by the protocol and was considered valid.

 

Due to the low solubility of C. I. Pigment Violet 55 in test medium, concentration levels that might be toxic for algae could not be reached.

 

The EL₅₀for inhibition of both growth rate (72h-E_RL₅₀) and yield (72h-E_YL₅₀) was above 100 mg/l.

The 72h-NOELR for growth rate inhibition was above 100 mg/l. The 72h-NOELR for yield inhibition was above 10 mg/l.