OECD 201: Freshwater Alga and Cyanobacteria, Growth Inhibition Test
OECD 201 is a standard freshwater algae and cyanobacteria Growth inhibition test commonly used for aquatic toxicology testing.
OECD 201 determines the effects a substance has on the growth of freshwater micro-algae or cyanobacteria through an acute aquatic plant growth toxicity test. OECD 201 exposes exponentially growing organisms to the test substance over a 72 hour test period.
Even though there is a short test duration, OECD 201 can assess the affects a substance will have over several generations of the test organism.
The OECD 201 test method recommends at least five test concentrations. Conducting a range-finding test before the OECD 201 analysis to determine the range of test concentrations to use for the definitive test is highly recommended.
For a more complex or Tier II Phytotoxity study, customers commonly request OECD 221, a Growth Inhibition Test against Lemna species.
Low water soluble lubricants or other material types may require a Water Accommodated Fraction (WAF) analysis prior to toxicology testing. Please contact the lab to discuss additional testing for WAF determination.
For any Environmental Fate or Ecological effects study, it is important to have data on the test substance’s water solubility (OECD 105)* and the vapor pressure. It is also beneficial to have data on the different performance, and physical and chemical properties of the material including structural formula, purity of the substance, stability in water and light, the Partition Coefficient (OECD 117)*, Dissociation Constants in water (OECD 112)*, and results of a test for ready biodegradability*.
As part of the Ecological effects data requirements for EPA pesticide registration, Tier I: Nontarget Area Phytotoxicity data is required for Typical End-use products (TEP) and some Technical Grade Active Ingredients (TGAI). To meet the Aquatic plant growth (algal and aquatic vascular plant toxicity) requirements, customers commonly request the EPA guideline, OSCPP 850.4500, which utilized OECD 201 as a source material to harmonize the OSPP guideline with OPPT, OPP and OECD procedures for algal toxicity testing. Depending on the results of Tier I studies, Tier II and Tier II testing may be required.
The EPA guideline OSCPP 850.4400 is commonly requested to fulfill Tier II testing for EPA pesticide submission, which is an OSCPP Growth Inhibition Test against Lemna species.
* Please inquire with the lab to set up a GLP Toxicology Study.
For more information on Toxicology Testing, contact our Environmental Testing laboratory at 847-483-9950 or firstname.lastname@example.org.