In short
OECD 423 is a structured acute oral toxicity method that uses sequential groups and predefined decision rules. Correct execution depends on the official guideline, appropriate ethical approval, trained personnel, careful observations and transparent reporting.
What OECD 423 is designed to do
The acute toxic class method is used to classify acute oral toxicity through a stepwise procedure rather than estimating a precise LD50 from large animal numbers. The official OECD guideline and local ethical requirements remain the controlling references for execution.
Core planning elements
- Test-item identity and formulation details
- Scientifically justified starting conditions
- Sequential decision-making according to the guideline
- Defined observation schedule and humane endpoints
- Complete raw-data capture and deviation documentation
- Final interpretation consistent with the observed outcome and guideline framework
Why reporting quality matters
A toxicity report should make the study traceable: what was administered, how observations were made, what deviations occurred, and how the conclusion was reached. A polished table cannot compensate for incomplete raw observations or undocumented decisions.
How complementary assays can strengthen interpretation
When included in an approved research plan, biochemical, histological or molecular measurements may provide additional mechanistic context. They should be presented as complementary endpoints and not confused with the core classification logic of OECD 423.
Frequently asked questions
Is OECD 423 the same as a conventional LD50 test?+
No. OECD 423 is an acute toxic class method using a stepwise classification approach rather than a traditional precise LD50 determination.
Can OECD 423 be run without ethical approval?+
No. Animal studies require the relevant institutional and ethical approvals before execution.
Can molecular endpoints be added?+
They can be considered as supplementary research endpoints when scientifically justified and covered by the approved study plan.
Does this article replace the OECD guideline?+
No. The current official OECD guideline and applicable regulatory and ethical requirements must be followed.