Acute systemic toxicity

Area of Science:

• Toxicology
• Animal Welfare Science
• Regulatory Science

Background:

• The LD50 test, a controversial method for determining acute toxicity, has been widely used for decades.
• Ethical concerns and scientific limitations have driven the search for alternatives to traditional animal testing.

Purpose of the Study:

• To announce the discontinuation of the LD50 test by the end of 2002.
• To introduce and advocate for the adoption of three validated alternative animal tests for acute toxicity assessment.
• To discuss the potential role of in vitro cytotoxicity tests in refining animal testing strategies.

Main Methods:

• The study focuses on the implementation of three alternative animal tests: the fixed dose procedure, the acute toxic class method, and the up and down procedure.
• These methods have been revised for improved scientific performance and regulatory acceptance.
• In vitro cytotoxicity tests are proposed as adjuncts for dose selection and animal number reduction.

Main Results:

• The three alternative animal tests are now suitable for a comprehensive strategy of acute toxicity testing across all substance types and regulatory contexts.
• In vitro cytotoxicity tests may be utilized by mid-2002 to aid dose selection and reduce animal usage.
• Significant further development and validation are required for the complete replacement of animal tests, estimated to take at least 10 years.

Conclusions:

• The LD50 test is being replaced by more ethical and scientifically robust alternative animal testing methods.
• A combination of alternative animal tests and in vitro methods offers a path towards improved animal welfare in toxicology.
• While significant progress has been made, the complete elimination of animal testing necessitates continued research and validation efforts.