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Ecotoxicological information

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:
Juni-11 until Nov-11
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: study conducted under GLP conditions and in acc. with OECD guideline

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report date:
2011

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 201 (Alga, Growth Inhibition Test)
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
Nadide
EC Number:
200-184-4
EC Name:
Nadide
Cas Number:
53-84-9
Molecular formula:
C21H27N7O14P2
IUPAC Name:
nadide
Constituent 2
Reference substance name:
b-nicotinamide-adenine-dinucleotide II (nadide)
IUPAC Name:
b-nicotinamide-adenine-dinucleotide II (nadide)
Test material form:
solid: crystalline
Details on test material:
Molecular formula C21H27N7O14P2
Molecular weight 663.44
Description off-white crystalline powder
Expiry date 29 February 2012

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no
Details on test solutions:
preparation of test solutions started with a concentration of 100 mg/L. no other treatment than vigorous shaking was needed to completely dissolve the test substance in medium. the lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. the final test solutions were all clear and colourless.
after preparation, volumes 50 ml were added to each replicate of the respective test concentration, subsequently, 1 ml of an algal suspension was added to each replicate providing a cell density of 10x4 cells/ml

Test organisms

Test organisms (species):
Pseudokirchneriella subcapitata (previous names: Raphidocelis subcapitata, Selenastrum capricornutum)
Details on test organisms:
- Common name: Pseudokirchneriella subcapitata
- Strain: NIVA CHL 1
- Source: in house laboratory culture

Study design

Test type:
static
Water media type:
freshwater
Limit test:
yes
Total exposure duration:
72 h

Results and discussion

Effect concentrationsopen allclose all
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 51 mg/L
Nominal / measured:
meas. (TWA)
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
EC50
Effect conc.:
> 51 mg/L
Nominal / measured:
meas. (TWA)
Basis for effect:
biomass
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
ca. 51 mg/L
Nominal / measured:
meas. (TWA)
Basis for effect:
growth rate
Duration:
72 h
Dose descriptor:
NOEC
Effect conc.:
51 mg/L
Nominal / measured:
meas. (TWA)
Basis for effect:
biomass

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
under the conditions of the present study w Pseudokirchneriella sbucapitata, no reduction of growth rate or inhibition of yield was recorded at any of the concentrations of nadide tested. the EC50 for growth rate reduction and the EC50 for yield inhibition were beyond the range tested, i.e. exceeded a Time Weighted Average concentration of 51 mg/L.
The NOEC for growth rate reduction and yield inhibition was 51 mg/L based on a TWA concentration.
Executive summary:

Pseudokirchneriella subcapitata, Fresh Water Algal Growth Inhibition with nadide.

The study procedures described in this report were based on the OECD guideline No. 201, 2006. In addition, the procedures were designed to meet the test methods of theCommissionRegulation (EC) No 440/2008, Part C.3, 2008; Amended by EC No. 761/2009and the ISO International Standard 8692, 2004.

The batch of nadide tested was a off-white crystalline powder with a purity of 98% and completely soluble in test medium at the concentrations tested.

A combined limit/range-finding test was performed. Preparation of test solutions started with a concentration of 100 mg/l. No other treatment than vigorous shaking was needed to completely dissolve the test substance. The lower test concentrations were prepared by subsequent dilutions of the highest concentration in test medium. The final test solutions were all clear and colourless.

Six replicates of exponentially growing algal cultures per group were exposed to a control and the concentration of 100 mg/l in the limit test. In addition three replicates per group were exposed to 0.1, 1.0 and 10 mg/l in a range-finding test. The initial cell density was 104cells/ml. The total exposure period was 72 hours and samples for analytical confirmation of the exposure concentrations were taken at the beginning, 24 hours after test initiation and at the end of the test.

at the start of the test, the actual test concentration taken from nominally 100 mg/L was in agreement with nominal. the meas. concentration dropped to 7% of initial at the end of the test. however, the meas. concentration in the samples taken from the solution without algae remained fairly constant (76% initial). the test substance was most probably metabolized by the algal biomass.

based on these results, the TWA concentration was calculated to be 51 mg/L.

No reduction of growth rate or inhibition of yield was recorded at any of the concentrations nadide tested.

The EC50for growth rate reduction (ERC50: 0-72h) and the EC50for yield inhibition (EYC50: 0-72h) were beyond the range tested,

i.e. exceeded a time weighted average concentration of 51 mg/L

The NOEC for growth rate reduction and yield inhibition was 51 mg/l based on a TWA concentration.