Registration Dossier

Ecotoxicological information

Toxicity to aquatic algae and cyanobacteria

Currently viewing:

Administrative data

Link to relevant study record(s)

Description of key information

96 -hour ErC50 of 7,5 mg/L and a NOEC of 1 mg/L

Key value for chemical safety assessment

Additional information

A study was performed to assess the effect of the test material on the growth of the green alga Pseudokirchneriella subcapitata. The method followed the OECD Guidelines for Testing of Chemicals (1984) No 201, "Alga, Growth Inhibition Test" referenced as Method C.3 of Commission Directive 92/69/EEC (which constitutes Annex V of Council Directive 67/548/EEC), US CFR Title 40 Part 797 Section 1050 and the US EPA Draft Ecological Effects Test Guideline OPPTS 850.5400.

The test material was known to degrade immediately on contact with water forming N-butylpyridinium chloride, hydrochloric acid and aluminium oxides. Following a preliminary range-finding test, Pseudokirchneriella subcapitata was exposed to an aqueous solution of the test material degradation products at concentrations of 1.0, 2.0, 4.0, 8.0 and 16 mg/L (three replicate flasks per concentration) for 96 hours, under constant illumination and shaking at a temperature of 24 +/- 1 °C. Samples of the algal populations were removed daily and cell concentrations determined for each control and treatment group, using a Coulter Multisizer Particle Counter. Exposure of Pseudokirchneriella subcapitata to the test material degradation products gave an an ErC50(0 - 96 h) value of 7.5 mg/L; The No Observed Effect Concentration was 1.0 mg/L. Chemical analysis of the test preparations was carried out using the degradation product, N-butylpyridinium chloride, as a marker. Analysis of the test preparations at 0 and 96 hours showed measured test concentrations of N-butylpyridium chloride to be near expected and so the results are based on nominal test concentrations.