Conventional Test Method:

Acute Oral LD50

(formerly OECD TG 401, now deleted as a test method)

Alternative Test Method:

Name & Description:

Acute Toxic Class Method

Test compound is administered orally to a group of three animals (rodents) in a sequential manner using a fixed dose of 5, 50, 300 or 2000 mg/kg as the starting dose. Absence or presence of compound-related mortality of the animals dosed at one step will determine the next step: i) no further testing is needed; ii) three additional animals are dosed with the same dose; or iii) three additional animals are dosed at the next higher or the next lower dose level. Animals are observed for a total of 14 days generally.

Validation Status:

EU: Endorsed as equivalent to scientifically validated by ESAC

US: none
Regulatory Status:

OECD: TG 423 (2001)

Effect or Potential Effect on Animal Use:

Reduction
(Reduces the number of animals used per test from 25 to 5-9)

References:
  • Diener W., Mische U., Schlede E. and Kayser D. (1995) The international validation study of the acute toxic class method (oral). Archives of Toxicology 69(10):659-670.
  • Diener W. and Schlede. E. (1999) Acute Toxic Class Methods: Alternatives to LD/LC50 Tests. ALTEX 16(3):129-134.
  • ECVAM (2007) ESAC statement on the OECD adopted test guidelines for acute oral toxicity testing.
  • OECD (2001) Test No. 423: Acute Oral Toxicity – Acute Toxic Class Method, OECD Guidelines for the Testing of Chemicals, Section 4 Health Effects.
  • Schlede E., Mischke U., Roll R. and Kayser D. (1992) A national validation study of the acute-toxic-class method – an alternative to the LD50 test. Archives of Toxicology 66(7):455-470.
  • Schlede E., Mischke U., Diener W. and Kayser D. (1995) The international validation study of the acute class method (oral). Archives of Toxicology 69(10):659-670.
Information Last Updated:
May 2012