1-(4-methyl-2-nitrophenylazo)-2-naphthol

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)

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)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

1-(4-methyl-2-nitrophenylazo)-2-naphthol

EC Number:

219-372-2

EC Name:

1-(4-methyl-2-nitrophenylazo)-2-naphthol

Cas Number:

2425-85-6

Molecular formula:

C17H13N3O3

IUPAC Name:

1-(4-methyl-2-nitrophenylazo)-2-naphthol

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Sampling and analysis

Analytical monitoring:

yes

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

Limit test:

no

Total exposure duration:

72 h

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

> 6 µg/L

Nominal / measured:

meas. (geom. mean)

Conc. based on:

test mat.

Basis for effect:

growth rate

Any other information on results incl. tables

Algae main test showed no adverse effects on the algae  up to the highest test concentration (solubility in medium)

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

In conclusion, the test item C.I. Pigment Red 3 had no acute toxic effects on Pseudokirchneriella subcapitata up to its solubility limit in the test water under the present test conditions.

Executive summary:

The influence of the test item C.I. Pigment Red 3 on the growth of the freshwater green algal species Pseudokirchneriella subcapitata was investigated in a 72‑hour static test according to the OECD Guideline 201 (2006) and the Commission Regulation (EC) No 761/2009, C.3.

Due to the low water solubility of the test item, a dispersion of the test item with the loading rate of 100 mg/L was continuously stirred at room temperature in the dark over 24 hours. Then, the dispersion was filtered. Theundiluted filtrate with the loading rate of 100 mg/L and dilutions 1:2.2, 1:4.6, 1:10 and 1:22 of the undiluted filtratewere used as test media. Additionally, a control was tested in parallel.

The preparation of the test media was based on the OECD Guidance Document on Aquatic Toxicity Testing of Difficult Substances and Mixtures, 2000.

At the start and end of the test, the measured test item concentrations in the test media with the loading rate of 100 mg/L(undiluted filtrate) were 6.91 and 5.19 µg/L, respectively.

The reported biological results were based on the mean measured concentration of 6.0 µg/L (calculated as the geometric mean of the concentration measured at the start and end of the test). In conclusion, the test item C.I. Pigment Red 3 had no acute toxic effects on Pseudokirchneriella subcapitata up to its solubility limit in the test water under the present test conditions.