Carbendazim

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:

May 1988

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Carbendazim

EC Number:

234-232-0

EC Name:

Carbendazim

Cas Number:

10605-21-7

Molecular formula:

C9H9N3O2

IUPAC Name:

carbendazim

Test solutions

Vehicle:

no

Details on test solutions:

Five test concentrations plus one control were tested in triplicate. Rifty ml of algal pre-culture were added to 50 ml of sterile nutrient medium containing the appropriate amount of the test substance. All test vessels were loosely stoppered and placed at random in an orbital incubator. The cultures were incubated, without media renewal, for 120 hrs under continuous illuminations of app. 700 lux. This level of illumination was necessay to ensure satisfactory growth at 72 h in compliance with OECD guideline.

Test organisms

Test organisms (species):

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

Study design

Total exposure duration:

72 h

Test conditions

Test temperature:

24 +/- 1 °C

pH:

Initial pH of the nutrient medium was 7.5.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

0.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

1.3 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

biomass

Details on results:

There were no abnormalities detected in controls or test cultures at 0.05 and 1.0 mg/l. Test concentrations of 2.0, 4.0 and 8.0 mg/l appeared to be clumped. Aliquots (0.5 ml) were removed from each replicate culture at the lowest test concentrations resulting in severe inhibition (8.0 mg/l) and the replicate pooled. One hundred ml of fresh sterile nutrient medium was added to ensure that the test concentration was reduced to below the inhibition lever. The subcultures were incubated at 24°C for 9 days. regrowth occurred in the control but not test culture after a period of 9 day demonstrating that the test substance was algicidal.

Applicant's summary and conclusion

Conclusions:

The EbC50(72 hr) was calculated as 1.3 mg/l. Lack of regrowth of inhibited cultures indicated that the test substance is algicidal. The NOEL was determined to be 0.5 mg carbendazim/l under test conditions.