2-hydroxybenzimidazole

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:

4.5.2009 - 7.5.2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: well performed OECD and GLP study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

2-hydroxybenzimidazole

EC Number:

210-412-4

EC Name:

2-hydroxybenzimidazole

Cas Number:

615-16-7

Molecular formula:

C7H6N2O

IUPAC Name:

2-hydroxybenzimidazole

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

yes

Total exposure duration:

72 h

Test conditions

Reference substance (positive control):

yes

Remarks:

Potassium dichromate CAS No. 7778-50-9

Results and discussion

Effect concentrations

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 100 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: na

Any other information on results incl. tables

	Rate-related inhibition (mg/L)
ErC10	> 100
ErC20	> 100
ErC50	> 100

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

With reference to this study the test item does not inhibit the algae growth

Executive summary:

In this study the effects of the test item2-Benzimidazololon the growth of the freshwatergreen alga Desmodesmus subspicatuswere tested. No inhibiting effects on specific growth rate and yield were found at the limit concentration of 100 mg/L. The EC₅₀-values for specific growth rate inhibition (E_rC₅₀) and inhibition of yield (E_yC₅₀) after 72 h were > 100 mg/L.