BMS 233110-01

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:

16th June 1999 - 29 September 1999

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

429-080-9

EC Name:

-

Cas Number:

198904-85-7

Molecular formula:

C17 H21 N3 O2

IUPAC Name:

Tert-butyl 2-[4-(2-pyridinyl) phenylmethyl] hydrazine carboxylate

Test material form:

solid: bulk

Specific details on test material used for the study:

Identity of test material same as for substance defined in section 1, white powder with 98.4% purity

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

Identity and concentration of auxiliary solvent for dispersal: No auxiliary solvent was required.

Test organisms

Test organisms (species):

Selenastrum sp.

Details on test organisms:

Selenastrum capricornutum (new name: Pseudokirchnerella subcapitata), strain CCAP 278/4

Study design

Test type:

static

Limit test:

no

Total exposure duration:

72 h

Test conditions

Nominal and measured concentrations:

The measured concentrations of BMS 233110-01 in the test media were determined at the start and end of the exposure period. The mean measured concentrations in the 0.32, 0.63, 1.25, 2.5, 5.0 and 10 mg/L treatments were 0.28, 0.52, 1.05, 1.98, 4.15 and 8.24 mg/L respectively, representing 88, 83, 84, 79, 83 and 82% of nominal exposure concentrations. Therefore the toxicity of BMS 233110-01 was based on the mean measured exposure concentrations.

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

4.3 mg/L

Basis for effect:

biomass

Effect concentrations 2

Key result

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

5.68 mg/L

Basis for effect:

growth rate

Effect concentrations 3

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.98 mg/L

Basis for effect:

growth rate

Effect concentrations 4

Key result

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

1.98 mg/L

Basis for effect:

biomass

Details on results:

The inhibition of growth of S. capricornutum exposed to BMS 233110-01 was based on mean measured exposure concentrations

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Based on the average specific growth rate, the 0-72hr ErC50 of BMS233110-01 to S.Capricornutum was calculated to be 5.68 mg/l. Based on the area under the growth curve, the 0-72hr EbC50 of BMS233110-01 to S.Capricornutum was calculated to be 4.30 mg/l.
Based on both the average specific growth rate and the area under the growth curve, the highest no observed effect concentrations (NOECs) of BMS233110-01 to S.Capricornutum were calculated to be 1.98mg/l.

Executive summary:

The nominal concentration range used in the definitive test was 0.32, 0.63, 1.25, 2.5, 5.0 and 10 mg/L. The range of concentrations was based on the results of a rangefinding

test, which is not reported. A 10 mg/L stock solution was prepared by direct addition of BMS 233110-01 to nutrient medium. The stock solution was used to provide the 10 mg/L treatment and further diluted with nutrient medium to prepare the following nominal concentrations: 0.32, 0.63, 1.25, 2.5 and 5.0 mg/L. A control treatment was prepared by the addition of nutrient medium only to the test vessels.

The measured concentrations ofBMS 233110-01 in the test media were determined at the start and end of the exposure period. The mean measured concentrations in the 0.32, 0.63, 1.25, 2.5, 5.0 and 10 mg/L treatments were 0.28, 0.52, 1.05, 1.98, 4.15 and 8.24 mg/L respectively, representing 88, 83, 84, 79, 83 and 82% of nominal exposure concentrations. Therefore the toxicity of BMS 233110-01 was based on the mean measured exposure concentrations.

Based on the average specific growth rate (μ) the 0 to 72 hours ErCso of BMS 233110-01 to S. capricornutum was calculated to be 5.68 mg/L (95% confidence limits could not be calculated). Based on the area under the growth curves , the 0 to 72 h EbCso of BMS 233110-01 to S. capricornutum was calculated to be 4.30 mg/L (95% confidence limits could not be calculated).

The highest no observed effect concentrations (NOEC's) of BMS 233110-01 to S. capricornutum were calculated to be 1.98 mg/L.