2-[3-(1,3-dihydro-1,3,3-trimethyl-2H-indol-2-ylidene)prop-1-enyl]-1,3,3-trimethyl-3H-indolium acetate

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

Justification for type of information:

Data for the target chemical is summarized based on the structually and functionally 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: refer below principle

Principles of method if other than guideline:

WoE study was prepared for toxicity of test chemical by considering WoE 2 and 3.

GLP compliance:

not specified

Analytical monitoring:

no

Test organisms (species):

other: 3: Prototheca wickerhamii

Details on test organisms:

3:
Common Name: Algae
Age: 48 h

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Remarks on exposure duration:

3: 48 h

Test temperature:

3: 32°C

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.2 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.022 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

0.14 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: AUG

Remarks on result:

other: 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.022 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: AUG

Remarks on result:

other: 2

Duration:

48 h

Dose descriptor:

other: % ihibition

Effect conc.:

> 0.01 - < 0.1 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Remarks on result:

other: 3

Details on results:

For the test chemical, based on effect on growth rate of the test organism green algae, the 72 hr EC50 and NOEC value was determined to be 0.20 mg/l and 0.022 mg/l, respectively and on the basis of AUG, the 72 hr EC50 and NOEC value was determined to be 0.14 mg/l and 0.022 mg/l, respectively while after 48h of study the % inhibition was determined to be ranges from 0.01 to 0.1mg/l.

Validity criteria fulfilled:

not specified

Conclusions:

For the test chemical, based on effect on growth rate of the test organism green algae, the 72 hr EC50 and NOEC value was determined to be 0.20 mg/l and 0.022 mg/l, respectively and on the basis of AUG, the 72 hr EC50 and NOEC value was determined to be 0.14 mg/l and 0.022 mg/l, respectively while after 48h of study the % inhibition was determined to be ranges from 0.01 to 0.1mg/l.

Executive summary:

Data available for the structurally similar and closely related read across chemicals study has been reviewed to determine the short term toxicity of the test chemical on the growth of aquatic algae. The studies are as mentioned below:

In first sudy, toxicity to green algae was carried out for assessing the effect of the test chemical. The study was conducted for 72 hrs. On the basis of growth rate of the test organism green algae, the 72 hr EC50 and NOEC value was determined to be 0.20 mg/l and 0.022 mg/l, respectively and on the basis of AUG, the 72 hr EC50 and NOEC value was determined to be 0.14 mg/l and 0.022 mg/l, respectively, thus chemical can be considered as toxic to aquatic algae and can be considered to be ‘’catoegory chronic-1’’ as per CLP classification criteria.

The second study was conducted to determine the toxicity of test chemical on aquatic algae. The study was conducted in static system for 48h. The test was performed on freshwater algae Prototheca wickerhamii at 32°C to observe the % inhibition of test chemical on the population of the algae. Hence, after 48h of study the % inhibition was determined to be ranges from 0.01 to 0.1mg/l.

On the basis of above observation, test chemical can be considered as toxic to aquatic algae and can be considered to be ‘’catoegory chronic-1’’ as per CLP classification criteria.

Description of key information

For the test chemical, based on effect on growth rate of the test organism green algae, the 72 hr EC50 and NOEC value was determined to be 0.20 mg/l and 0.022 mg/l, respectively and on the basis of AUG, the 72 hr EC50 and NOEC value was determined to be 0.14 mg/l and 0.022 mg/l, respectively while after 48h of study the % inhibition was determined to be ranges from 0.01 to 0.1mg/l.

Key value for chemical safety assessment

EC50 for freshwater algae:

0.2 mg/L

EC10 or NOEC for freshwater algae:

0.022 mg/L

Additional information

Data available for the structurally similar and closely related read across chemicals study has been reviewed to determine the short term toxicity of the test chemical on the growth of aquatic algae. The studies are as mentioned below:

In first sudy, toxicity to green algae was carried out for assessing the effect of the test chemical. The study was conducted for 72 hrs. On the basis of growth rate of the test organism green algae, the 72 hr EC50 and NOEC value was determined to be 0.20 mg/l and 0.022 mg/l, respectively and on the basis of AUG, the 72 hr EC50 and NOEC value was determined to be 0.14 mg/l and 0.022 mg/l, respectively, thus chemical can be considered as toxic to aquatic algae and can be considered to be ‘’catoegory chronic-1’’ as per CLP classification criteria.

The second study was conducted to determine the toxicity of test chemical on aquatic algae. The study was conducted in static system for 48h. The test was performed on freshwater algae Prototheca wickerhamii at 32°C to observe the % inhibition of test chemical on the population of the algae. Hence, after 48h of study the % inhibition was determined to be ranges from 0.01 to 0.1mg/l.

On the basis of above observation, test chemical can be considered as toxic to aquatic algae and can be considered to be ‘’catoegory chronic-1’’ as per CLP classification criteria.