2-benzoylbenzoic acid

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

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

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Freshwater Alga and Cyanobacteria, Growth Inhibition Test)

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

yes

Remarks:

HPLC/DAD

Vehicle:

yes

Remarks:

test item

Details on test solutions:

The test item was not soluble. A special solubilization protocol was carried out before the experimentation according to the OECD23 guidance document on aquatic toxicity testing of difficult substances and mixtures. This method consists in stirring each test item nominal concentrations in test medium during 24h, in the dark and 20±2°C.

Test organisms (species):

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

Test type:

semi-static

Water media type:

other: test medium

Limit test:

no

Total exposure duration:

72 h

Test temperature:

22 - 23°C

Nominal and measured concentrations:

10 - 32 - 102 - 328 and 1050 mg/L

Reference substance (positive control):

yes

Remarks:

K2Cr2O7

Key result

Duration:

72 h

Dose descriptor:

EL50

Remarks:

growth rate

Effect conc.:

> 1 050 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EL10

Remarks:

growth rate

Effect conc.:

732 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Key result

Duration:

72 h

Dose descriptor:

EL50

Remarks:

% yield inhibition

Effect conc.:

1 000 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: % yield inhibition

Key result

Duration:

72 h

Dose descriptor:

EL10

Remarks:

% yield inhibition

Effect conc.:

255 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Remarks on result:

other: % yield inhibition

Details on results:

The validity criteria were successfully fulfilled.

Results with reference substance (positive control):

not specified

Validity criteria fulfilled:

yes

Conclusions:

The toxicity potential on aquatic algae was determined according to the OECD201 guideline. The results obtained for the test item on the toxicological endpoint "inhibition of growth rate" and "yield inhibition" were :
- EL50 (growth rate) - 72h > 1050 mg/L
- EL10 (growth rate) - 72h = 732 mg/L
- EL50 (yield) - 72h = 1000 mg/L
- EL10 (yield) - 72h = 255 mg/L
Regarding these results, the test item is not considered as toxic for aquatic algae.

Executive summary:

The toxicity potential on aquatic algae was determined according to the OECD201 guideline. The results obtained for the test item on the toxicological endpoint "inhibition of growth rate" and "yield inhibition" were :

- EL50 (growth rate) - 72h > 1050 mg/L

- EL10 (growth rate) - 72h = 732 mg/L

- EL50 (yield) - 72h = 1000 mg/L

- EL10 (yield) - 72h = 255 mg/L

Regarding these results, the test item is not considered as toxic for aquatic algae.

Description of key information

The toxicity potential on aquatic algae was determined according to the OECD201 guideline. The results obtained for the test item on the toxicological endpoint "inhibition of growth rate" and "yield inhibition" were:

- EL50 (growth rate) - 72h > 1050 mg/L

- EL10 (growth rate) - 72h = 732 mg/L

- EL50 (yield) - 72h = 1000 mg/L

- EL10 (yield) - 72h = 255 mg/L

Regarding these results, the test item is not considered as toxic for aquatic algae.

Key value for chemical safety assessment

EC50 for freshwater algae:

1 050 mg/L