Archives of Toxicology

, Volume 47, Issue 2, pp 77–99 | Cite as

Significance of the LD50-test for the toxicological evaluation of chemical substances

  • G. Zbinden
  • M. Flury-Roversi
Review Article


The LD50-test was developed in 1927 for the biological standardization of dangerous drugs. Then it was incorporated into the routine toxicological protocol of other classes of chemical compounds and is now part of practically all governmental guidelines which regulate toxicological testing of chemicals.

For scientific, economic, and ethical reasons it is necessary to periodically reassess all toxicological test procedures, including the LD50-test. Tests which are not optimal or that have become obsolete because of new scientific knowledge, must be changed or eliminated.

The review of the LD50-test shows that the precision of the procedure is dependent on the number of animals used. But even with large numbers of animals there are considerable variations of the test results, because the numerical value of the LD50 is influenced by many factors, such as animal species and strain, age and sex, diet, food deprivation prior to dosing, temperature, caging, season, experimental procedures, etc. Thus, the LD50 value cannot be regarded as a biological constant.

Through standardization of the test animals and the experimental conditions the variability of the LD50 determinations can be reduced but never fully eliminated.

There are several tests with which an approximate LD50 can be determined. These methods use fewer animals than the classical LD50-test, but their precision and reproducibility are sufficient for most purposes of acute toxicity testing.

Through incorporation of physiological, hematological, biochemical, pathological, and histopathological investigations in the simplified test procedures with small numbers of animals, it is possible to markedly increase the informational content of the results with regard to the toxicological spectrum and the target organs of toxicity. Such studies have already replaced the LD50-test in large animals, such as dogs and monkeys. It is also desirable to replace the LD50 in rodents with such a procedure.

With pharmacologically inert compounds that have no acute effects with single administration the classical LD50-test does not provide relevant toxicological results.

For the prediction of the human lethal dose and for the prediction of the symptomatology of poisoning after acute overdosing in man the LD50-test is of limited usefulness. An acute toxicity test with small numbers of animals combined with comprehensive studies of physiological functions, biochemical and histopathological examinations often provides more important information for emergency physicians and poison control centers.

For the selection of doses to be used in subacute and chronic toxicity experiments the LD50-test does not provide consistent and reliable results. A simple pilot experiment with few animals but repeated dosing gives more useful information.

For the evaluation of special risks for the human newborn and infant the LD50-test is poorly suited.

For the appraisal of pharmacokinetic behavior and bioavailability the LD50-test gives only semi-quantitative, often ambiguous information.

In all cases where the acute toxicity testing is mainly concerned with the evaluation of toxicological potential of the test substances, the symptomatology following acute overdosing, and the knowledge of target organs of toxicity, the classical LD50-test should be replaced by a more comprehensive short term test that can be done with small numbers of animals. The classical LD50-test should only be permitted in those rare instances where a high precision of the LD50 determination is indispensable.

Key words

LD50-test Acute toxicity 


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  1. A.B.P.I. (1977) Report on the LD50-test for the advisory committe on the administration of the cruelty to animals act, 1876 Unpublished document issued by the Association of the British Pharmaceutical IndustryGoogle Scholar
  2. Balazs T (1970) Measurement of acute toxicity, in methods in toxicology. Blackwell Scientific Publications, Oxford and Edinburgh, p 49Google Scholar
  3. Balazs T (1972) Cardiotoxicity of isoproterenol in experimental animals. Influence of stress, obesity, and repeated dosing. In: Bajusz E, Rona G (eds) Recent advances in studies on cardiac structure and metabolism, vol 1. Urban & Schwarzenberg, München Berlin Wien, p 770Google Scholar
  4. Balazs T, Arena E, Barron CN (1972) Protection against the cardiotoxic effect of isoproterenol HCl by restricted food intake in rats. Toxicol Appl Pharmacol 21:237Google Scholar
  5. Behrens B (1929) Zur Auswirkung der Digitalisblätter im Froschversuch. Arch Exp Pathol Pharmacol 140:237–256Google Scholar
  6. Bliss CI (1935) The calculation of the dosage-mortality curve. Am Appl Biol 22: 134Google Scholar
  7. Brown AM (1962) Strain variation in mice. J Pharm Pharmacol 14:406–410Google Scholar
  8. Cobb LM, Grimshaw P (1979) Acute toxicity of oral diquat (1,1′-ethylene-2,2′-bipyridinium) in Cynomologus monkeys. Toxicol Appl Pharmacol 51:277–282Google Scholar
  9. Commission of the European Communities and United States Environmental Protection Agency (1979) Second Intercomparison Programme on LD50. Collection of Results. Colloquium: Quality Assurance of Toxicological Data. Luxembourg, December 11–13Google Scholar
  10. Conney AH (1967) Pharmacological implications of microsomal enzyme induction. Pharmacol Rev 19: 317–366Google Scholar
  11. Deichmann WB, LeBlanc TJ (1943) Determination of the approximate lethal dose with about six animals. J Ind Hyg Toxicol 25:415–417Google Scholar
  12. Deichmann WB, Mergard EG (1948) Comparative evaluation of methods employed to express the degree of toxicity of a compound. J Ind Hyg Toxicol 30: 373–378Google Scholar
  13. Dieke SH, Richter CP (1945) Acute toxicity of thiourea to rats in relation to age, diet, strain, and species variation. J Pharmacol Exp Ther 83: 195–202Google Scholar
  14. Dixon WJ, Mood AM (1948) A method for obtaining and analyzing sensitivity data. J Am Stat Assoc 43: 109–126Google Scholar
  15. Ellison T (1979) Toxicological effects testing. In: Dominquez G (ed) Guidebook, toxic substances control act. CRC Press Inc., Cleveland, Ohio, p 8.1Google Scholar
  16. Ferguson HC (1962) Dilution of dose and acute toxicity. Toxicol Appl Pharmacol 4: 759–762Google Scholar
  17. Fuhrman GJ, Fuhrman FA (1961) Effects of temperature on the action of drugs. Ann Rev Pharmacol 1:65–78Google Scholar
  18. Gaddum JH (1933) Reports on biological standards III methods of biological assay depending on a quantal response. MRC Special Report. M.S.O. London, Ser No 183Google Scholar
  19. Gleason MN, Gosselin RE, Hodge HC, Smith RP (1969) Clinical toxicology of commercial products. Acute poisoning, 3rd ed. Williams and Wilkins Co., BaltimoreGoogle Scholar
  20. Goldenthal EI (1971) A compilation of LD50 values in newborn and adult animals. Toxicol Appl Pharmacol 18: 185–207Google Scholar
  21. Hodel C, Leist KH, Anseeuw P (1975) A comparison of results from prolonged and acute toxicity studies in rats. Proc Eur Soc Toxicol 17: 171–178Google Scholar
  22. Hunter WJ, Lingk W, Recht P (not dated) An intercomparison study conducted by the Commission of the European Communities on the determination of the single administration toxicity in rats. Communicated by the Health and Safety Directorate. Commission of the European Communities (unpublished document)Google Scholar
  23. JECFA (Joint FAO/WHO Expert Committee on Food Additives) (1958) Procedures for the testing of intentional food additives to establish their safety for use. Wld Hlth Org Techn Rep Ser 144Google Scholar
  24. JECFA (Joint FAO/WHO Expert Committee of Food Additives) (1974) Toxicological evaluation of certain food additives with a review of general principles and of specification. Wld Hlth Org Techn Rep Ser 539Google Scholar
  25. JECFA (Joint FAO/WHO Expert Committee on Food Additives) (1977) Summary of toxicological data of certain food additives. WHO Food Additives Series, no 12, pp 9–13Google Scholar
  26. Jollow DJ, Thorgeirsson SS, Potter WZ, Hashimoto M, Mitchell JR (1974) Acetaminophen-induced hepatic necrosis. IV. Metabolic disposition of toxic and nontoxic doses of acetaminophen. Pharmacology 12: 251–271Google Scholar
  27. Kaplan SA, Jack ML (1979) In vitro, in situ, and in vivo models in biovailability assessment. In: Blanchard J, Sawchuk RJ, Brodie BB (eds) Principles and perspectives in drug biovailability. Karger, Basel, p 156Google Scholar
  28. Kärber G (1931) Beitrag zur kollektiven Behandlung pharmakologischer Reihenversuche. Arch Exp Pathol Pharmakol 162:480–482Google Scholar
  29. Krijnen CJ, Boyd EM (1970) Susceptibility to captan pesticide of albino rats fed foam weaning on diets containing various levels of protein. Food Cosmet Toxicol 8:35–42Google Scholar
  30. Kutob SD, Plaa GL (1962) A procedure for estimating the hepatotoxic potential of certain industrial solvents. Toxicol Appl Pharmacol 4:354–361Google Scholar
  31. Litchfield JT, Fertig JW (1961) On a graphic solution of the dosage-effect curve. Bull John Hopkins Univ 69: 276Google Scholar
  32. Litchfield JT, Jr, Wilcoxon F (1949) A simplified method of evaluating dose-effect experiments. J Pharmacol Ther 96: 99–113Google Scholar
  33. Miller LC, Tainter ML (1944) Estimation of the ED50 and its error by means of logarithmic probit graph paper. Proc Soc Exp Biol Med 57:261–264Google Scholar
  34. Molinengo L (1979) The curve doses vs survival time in the evaluation of acute toxicity. J Pharm Pharmacol 31:343–344Google Scholar
  35. Morrison JK, Quinton RM, Reinert H (1968) The purpose and value of LD50 determinations. Historical introduction. In: Boyland E, Goulding R (eds) Modern trends in toxicology Butterworths, London, p 1Google Scholar
  36. Müller R (1948) Vergleich der im Tierexperiment und beim Menschen tödlichen Dosen wichtiger Pharmaka. Diss Univ Frankfurt/MainGoogle Scholar
  37. Neubert D (1975) Die toxikologischen Voraussetzungen für die klinische Anwendung einer neuen Substanz. In: von Eickstedt KW, Gross F (Hrsg) Aus Klinische Arzneimittelprüfung. Symposium für klinische Pharmakologie des Bundesgesundheitsamtes Berlin. Fischer, Stuttgart, S. 22–42Google Scholar
  38. Peck HM (1968) An appraisal of drug safety evaluation in animals and the extrapolation of results to man. In: Tedeschi DH, Tedeschi RE (eds) Importance of fundamental principles in drug evaluation. Raven Press, New York, p 449Google Scholar
  39. Quinton RM, Reinert H (1968) Cited by Morrison JK, Quinton RM, Reinert H. In: Boyland E, Goulding R (eds) Modern trends in toxicology. Butterworths, London, pp 1–18Google Scholar
  40. Rat von Sachverständigen (1979) Stellungnahme des Rates von Sachverständigen für Umweltfragen vom 19. 4. 1979 zum Entwurf eines Chemikaliengesetzes vom 9. 2. 1979. Umweltbrief, Bundesminister des Inneren, Bonn, FRG, 19: 23–40Google Scholar
  41. Schweizerische Eidgenossenschaft (1969) Bundesgesetz über den Verkehr mit Giften (Giftgesetz)Google Scholar
  42. Smith FA, Downs WL, Hodge HC, Maynard EA (1960) Screening of fluorine-containing compounds for acute toxicity. Toxicol Appl Pharmacol 2:54–58Google Scholar
  43. Sperling F (1976) Nonlethal parameters as indices of acute toxicity: inadequacy of the acute LD50. In: Mehlmann M, Shapiro RE, Blumenthal H (eds) New concepts of safety evaluation. John Wiley and Sous, New York London Sydney Toronto, p 177Google Scholar
  44. Thompson WR (1947) Use of moving averages and interpolation to estimate median-effective dose. I. Fundamental formulas, estimation of error, and relation to other methods. Bacteriol Rev 11: 115–145Google Scholar
  45. Trevan JW (1927) The error of determination of toxicity. Proc Roy Soc 101B: 483–514Google Scholar
  46. Wegmann K (1969) Die neuen Vorschriften des Bundes über den Verkehr mit Giften. Schweiz Z Sozialvers 13: 287–301Google Scholar
  47. Weihe WH (1973) The effect of temperature on the action of drugs. Ann Rev Pharmacol 13:409–425Google Scholar
  48. Weil CS (1952) Tables for convenient calculation of median-effective dose (LD50 or ED50) and instructions in their use. Biometrics 8:249–263Google Scholar
  49. Weil CS, Wright GJ (1967) Intra- and interlaboratory comparative evaluation of single oral test. Toxicol Appl Pharmacol 11:378–388Google Scholar
  50. Wiberg GS, Grice HC (1965) Effect of prolonged individual caging on toxicity parameters in rats. Food Cosmet Toxicol 3:597–603Google Scholar
  51. Zbinden G (1963) Experimental and clinical aspects of drug toxicity. Adv Pharmac 2: 1–112Google Scholar
  52. Zbinden, G (1973) Acute toxicity, Progress in Toxicology, Special Topics, vol 1. Springer, Berlin Heidelberg New York, p 23Google Scholar

Copyright information

© Springer-Verlag 1981

Authors and Affiliations

  • G. Zbinden
    • 1
  • M. Flury-Roversi
    • 1
  1. 1.Institute of Toxicology, Swiss Federal Institute of Technology and the University of ZurichSchwerzenbachSwitzerland

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