2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl)azo]phenyl]azo]-, ar-styrenated

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

for read across substance

Justification for type of information:

Data for the target chemical is summarized based on the structurally similar read across chemicals

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: as mentioned below

Principles of method if other than guideline:

WoE report is based on two toxicity study of algae and cyanobacteria for the test chemical :1.To evaluate short term toxicity of test material on aquatic algae and cyanobacteria2.This study was designed to assess the effect of the test item on the growth of green alga Chlorella vulgaris. The study was conducted in accordance with “OECD guideline for testing of chemicals No. 201 – Alga, growth inhibition test”.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (as cited in study report): 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl) azo] phenyl] azo]-, ar-styrenated- IUPAC name: 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl) azo] phenyl] azo]-, ar-styrenated- Molecular formula: C40H36N4O1 - Molecular wt. : 588.76 g/mole- smiles : Cc1ccccc1N=Nc2ccc(c(C)c2)N=Nc3c4ccc(C(C)c5ccccc5)cc4cc(C(C)c6ccccc6)c3O- Substance type: Organic- Physical state: red liquid

Analytical monitoring:

not specified

Details on test solutions:

2.The test item was prepared by adding 12 mg of test item in 240 ml of BBM to get the final concentration of 50mg/L. This stock solution was kept for stirring for 30 minutes to obtain a homogenous solution for the experiment. The test concentrations were chosen according to the available data of the test item. The remaining test solutions were prepared by dilution from the above stock solution. To have a better growth and visibility of cells, the initial cell density of the culture was kept 1 X 104cells/ml. Care was taken to have a homogeneous solution for the experiment.

Test organisms (species):

Chlorella vulgaris

Details on test organisms:

2.The culture was examined under the microscope to confirm that it was unicellular, healthy and not contaminated. The medium to be used for the growth of algae was Bold’s Basal Medium (BBM). It is a medium composed of macronutrients, micronutrients, alkaline EDTA solution and Iron solution. Stock solution of each of these was prepared separately and then a complete medium was prepared and sterilized. De-ionized water was used to prepare the BBM.

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Test temperature:

2) 24 °C ±2°C

pH:

2) 6.7 to 7.4

Nominal and measured concentrations:

2) Six test concentration were:0.5 mg/l, 1.25mg/l,3.125mg/l, 7.813mg/l, 19.531mg/l and 48.828mg/l

Details on test conditions:

2) Light QualityWhite Fluoroscent LightLight Intensity1500LuxPhotoperiod16 Hour Light Period : 8 Hour Dark PeriodRPM Speed120 Revolutions per minuteWater Deionized WaerTest vessel size100mlTest solution volume60mlDilution waterBold’s Basal MediumTest concentration Six test concentration were: Replicates per concentrationThree replicates for ControlTwo replicates for each test concentration

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.61 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: calculated from porbit

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.15 mg/L

Nominal / measured:

not specified

Conc. based on:

test mat.

Basis for effect:

growth rate

Validity criteria fulfilled:

not specified

Conclusions:

The test chemical 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl) azo] phenyl] azo]-, ar-styrenated is likely to be toxic to aquatic algae and cyanobacteria atleast in the dose range of 0.15 - 0.61 mg/l

Executive summary:

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the short term toxicity of fish of the test chemical 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl) azo] phenyl] azo]-, ar-styrenated (85203 -90 -3).The studies are as mentioned below:

1.The test material was subjected to green algae under static condition for 72 hr to evaluate its toxicity on growth rate of green algae.The effect concentration (EC50) was observed to be 0.15 mg/l , No effect on growth (NOEC) was observed in the concentration 0.027 mg/l . The effect concentration of area under growth curve was observed to be 0.037 mg/l

2.The effect of test item was studied on the growth of fresh water green algaChlorella vulgaris.The study was conducted following OECD guideline 201- Alga, growth inhibition test. The test concentration chosen for the study were 0.5mg/l, 1.25mg/l, 3.125mg/l, 7.813mg/l, 19.531mg/l and 48.828mg/l. The test concentrations were prepared using stock solution of the test item using mineral media. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test item. EC50 calculated graphically through probit analysis was observed to be 0.610 mg/L.

Thus, based on the EC50 value, test substancecan be considered astoxic to aquatic organisms and thus can be classified as aquatic acute category 1 as per the CLP criteria.

Description of key information

Toxicity to aquatic algae and cyanobacteria:

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the short term toxicity of fish of the test chemical 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl) azo] phenyl] azo]-, ar-styrenated (85203 -90 -3).The studies are as mentioned below:

1.The test material was subjected to green algae under static condition for 72 hr to evaluate its toxicity on growth rate of green algae.The effect concentration (EC50) was observed to be 0.15 mg/l , No effect on growth (NOEC) was observed in the concentration 0.027 mg/l . The effect concentration of area under growth curve was observed to be 0.037 mg/l

2.The effect of test item was studied on the growth of fresh water green algaChlorella vulgaris.The study was conducted following OECD guideline 201- Alga, growth inhibition test. The test concentration chosen for the study were 0.5mg/l, 1.25mg/l, 3.125mg/l, 7.813mg/l, 19.531mg/l and 48.828mg/l. The test concentrations were prepared using stock solution of the test item using mineral media. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test item. EC50 calculated graphically through probit analysis was observed to be 0.610 mg/L.

Thus, based on the EC50 value, test substancecan be considered astoxic to aquatic organisms and thus can be classified as aquatic acute category 1 as per the CLP criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

0.61 mg/L

Additional information

Toxicity to aquatic algae and cyanobacteria:

Data available for the structurally and functionally similar read across chemicals has been reviewed to determine the short term toxicity of fish of the test chemical 2-Naphthalenol, 1-[[2-methyl-4-[(2-methylphenyl) azo] phenyl] azo]-, ar-styrenated (85203 -90 -3).The studies are as mentioned below:

1.The test material was subjected to green algae under static condition for 72 hr to evaluate its toxicity on growth rate of green algae.The effect concentration (EC50) was observed to be 0.15 mg/l , No effect on growth (NOEC) was observed in the concentration 0.027 mg/l . The effect concentration of area under growth curve was observed to be 0.037 mg/l

2.The effect of test item was studied on the growth of fresh water green algaChlorella vulgaris.The study was conducted following OECD guideline 201- Alga, growth inhibition test. The test concentration chosen for the study were 0.5mg/l, 1.25mg/l, 3.125mg/l, 7.813mg/l, 19.531mg/l and 48.828mg/l. The test concentrations were prepared using stock solution of the test item using mineral media. The green alga was exposed to the test concentration for a period of 72 hours to observe average specific growth rate and % growth inhibition under the effect of the test item. EC50 calculated graphically through probit analysis was observed to be 0.610 mg/L.

Thus, based on the EC50 value, test substancecan be considered astoxic to aquatic organisms and thus can be classified as aquatic acute category 1 as per the CLP criteria.