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OECD 225 – Lumbriculus Toxicity Test

OECD 225 assess the effects from prolonged exposure to sediment-associated chemicals on the endobenthic oligochaete Lumbriculus variegatus.oligochaetes play an important part on aquatic ecosystems; not only are they subject to chemical exposure, they are important food sources for many other aquatic animals.

OECD 225 is performed under static conditions where the test substance is used to spike the sediment.  Test organisms are exposed to the sediment-water system for 28 days.  OECD 225 determines the effects that the test substance has on the reproduction and biomass of the test organisms.  Measurements are made by determining the total number of surviving worms and measuring biomass at the termination of exposure.

The OECD 225 test method determines the EC50 concentration, but can also determine the No Observed Effect Concentration (NOEC) and the Lowest Observed Effect Concentration (LOEC) for the biomass and reproduction, if supporting data is available.

Sediment toxicity tests are important to regulators and scientists researching toxicity, bioaccumulation and bioavailability of chemicals to benthic organisms. Aquatic oligochaetes, like Lumbriculus variegatus, play an important role in the sediments of aquatic systems by bioturbation and by serving as prey; it has been documented that sediment-ingesting endobenthic animals are subject to potentially high exposure to sediment bound substances.

It is  important to have data on the test substance’s water solubility (OECD 105)* and the vapour pressure.  It can also be 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.

Many toxicology tests are used to meet regulatory requirements for different product applications; for any testing performed to meet regulatory or third party labeling requirements, it is strongly recommended to review requirements prior to testing with the appropriate agency to determine which tests should be performed for label claims or regulatory acceptance.

* OECD 105: Water Solubility

*OECD 112: Dissociation Constants in Water

*OECD 117: Partition Coefficient (n-octanol/water), HPLC Method

For more information on Toxicology Testing, contact our Environmental Testing laboratory at 847-483-9950 or info@situtest.com.