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Description of key information

ALGA, GROWTH INHIBITION TEST 
Testing facility: Bayer Industry Services, Leverkusen
Study no. 2006/0035/06 performed on May 29, 2006.
The study was conducted in accordance with EEC Methods for Determination of Ecotoxicity Annex to Directive 92/69/EEC (O.J. No. L383A, 29.12.92) Part C, Method 3 'Algal inhibition test' which is in most parts equivalent to the OECD Guideline for Testing of Chemicals No. 201 'Alga, Growth Inhibition Test'.
Algal species: Desmodesmus subspicatus
The registrant has a Letter of Access.

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Additional information

Exponentially growing algal cells were exposed for a period of 72 hours to a concentration range of concentrations, nominally 3.13, 6.3, 12.5, 25, 50 and 100 mg/l dissolved in water. Auxiliaries used to prepare the test media were an ultrasonic bath, a magnetic stirrer and a folded filter. The cell densities were measured at 24 hour intervals. Inhibition of the algal population was measured as reduction in growth (index b) and growth rate (index r), relative to control cultures grown under identical conditions. Growth and growth rates were used to calculate a NOEC and a LOEC according to Dunnett (1955, 1964). The following values were determined:

ErC 50 (0-72 h) : > 100 mg/l

EbC 50 (0-72 h) : > 100 mg/l

NOEC [b,r](t α 0.05) : ≥ 100 mg/l

LOEC [b,r](t α 0.05) : > 100 mg/l

No toxic effects against algae at a limit test concentration of 100 mg/L. All results are expressed in terms of nominal concentrations.