Median lethal dose

In toxicology, the median lethal dose, LD50 (abbreviation for "lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a measure of the lethal dose of a toxin, radiation, or pathogen.[1] The value of LD50 for a substance is the dose required to kill half the members of a tested population after a specified test duration. LD50 figures are frequently used as a general indicator of a substance's acute toxicity. A lower LD50 is indicative of increased toxicity.

The test was created by J.W. Trevan in 1927.[2] The term semilethal dose is occasionally used in the same sense, in particular with translations of foreign language text, but can also refer to a sublethal dose. LD50 is usually determined by tests on animals such as laboratory mice. In 2011, the U.S. Food and Drug Administration approved alternative methods to LD50 for testing the cosmetic drug Botox without animal tests.[3][4]

Conventions

The LD50 is usually expressed as the mass of substance administered per unit mass of test subject, typically as milligrams of substance per kilogram of body mass, sometimes also stated as nanograms (suitable for botulinum), micrograms, or grams (suitable for paracetamol) per kilogram. Stating it this way allows the relative toxicity of different substances to be compared, and normalizes for the variation in the size of the animals exposed (although toxicity does not always scale simply with body mass). For substances in the environment, such as poisonous vapors or substances in water that are toxic to fish, the concentration in the environment (per cubic metre or per litre) is used, giving a value of LC50. But in this case, the exposure time is important (see below).

The choice of 50% lethality as a benchmark avoids the potential for ambiguity of making measurements in the extremes and reduces the amount of testing required. However, this also means that LD50 is not the lethal dose for all subjects; some may be killed by much less, while others survive doses far higher than the LD50. Measures such as "LD1" and "LD99" (dosage required to kill 1% or 99%, respectively, of the test population) are occasionally used for specific purposes.[5]

Lethal dosage often varies depending on the method of administration; for instance, many substances are less toxic when administered orally than when intravenously administered. For this reason, LD50 figures are often qualified with the mode of administration, e.g., "LD50 i.v."

The related quantities LD50/30 or LD50/60 are used to refer to a dose that without treatment will be lethal to 50% of the population within (respectively) 30 or 60 days. These measures are used more commonly within Radiation Health Physics, as survival beyond 60 days usually results in recovery.

A comparable measurement is LCt50, which relates to lethal dosage from exposure, where C is concentration and t is time. It is often expressed in terms of mg-min/m3. ICt50 is the dose that will cause incapacitation rather than death. These measures are commonly used to indicate the comparative efficacy of chemical warfare agents, and dosages are typically qualified by rates of breathing (e.g., resting = 10 l/min) for inhalation, or degree of clothing for skin penetration. The concept of Ct was first proposed by Fritz Haber and is sometimes referred to as Haber's Law, which assumes that exposure to 1 minute of 100 mg/m3 is equivalent to 10 minutes of 10 mg/m3 (1 × 100 = 100, as does 10 × 10 = 100).

Some chemicals, such as hydrogen cyanide, are rapidly detoxified by the human body, and do not follow Haber's Law. So, in these cases, the lethal concentration may be given simply as LC50 and qualified by a duration of exposure (e.g., 10 minutes). The Material Safety Data Sheets for toxic substances frequently use this form of the term even if the substance does follow Haber's Law.

For disease-causing organisms, there is also a measure known as the median infective dose and dosage. The median infective dose (ID50) is the number of organisms received by a person or test animal qualified by the route of administration (e.g., 1,200 org/man per oral). Because of the difficulties in counting actual organisms in a dose, infective doses may be expressed in terms of biological assay, such as the number of LD50's to some test animal. In biological warfare infective dosage is the number of infective doses per cubic metre of air times the number of minutes of exposure (e.g., ICt50 is 100 medium doses - min/m3).

Limitation

As a measure of toxicity, LD50 is somewhat unreliable and results may vary greatly between testing facilities due to factors such as the genetic characteristics of the sample population, animal species tested, environmental factors and mode of administration.[6]

There can be wide variability between species as well; what is relatively safe for rats may very well be extremely toxic for humans (cf. paracetamol toxicity), and vice versa. For example, chocolate, comparatively harmless to humans, is known to be toxic to many animals. When used to test venom from venomous creatures, such as snakes, LD50 results may be misleading due to the physiological differences between mice, rats, and humans. Many venomous snakes are specialized predators on mice, and their venom may be adapted specifically to incapacitate mice; and mongooses may be exceptionally resistant. While most mammals have a very similar physiology, LD50 results may or may not have equal bearing upon every mammal species, such as humans, etc.

Examples

Note: Comparing substances (especially drugs) to each other by LD50 can be misleading in many cases due (in part) to differences in effective dose (ED50). Therefore, it is more useful to compare such substances by therapeutic index, which is simply the ratio of LD50 to ED50.

The following examples are listed in reference to LD50 values, in descending order, and accompanied by LC50 values, {bracketed}, when appropriate.

Substance Animal, Route LD50
{LC50}
LD50 : g/kg
{LC50 : g/L}
standardised		 Reference
Water rat, oral 90,000 mg/kg 90 [7]
Sucrose (table sugar) rat, oral 29,700 mg/kg 29.7 [8]
Glucose (blood sugar) rat, oral 25,800 mg/kg 25.8 [9]
Monosodium glutamate (MSG) rat, oral 16,600 mg/kg 16.6 [10]
Stevioside (from stevia) mice and rats, oral 15,000 mg/kg 15 [11]
Vitamin C (ascorbic acid) rat, oral 11,900 mg/kg 11.9 [12]
Glyphosate (isopropylamine salt of) rat, oral 10,537 mg/kg 10.537 [13]
Lactose (milk sugar) rat, oral 10,000 mg/kg 10 [14]
Aspartame mice, oral 10,000 mg/kg 10 [15]
Urea rat, oral 8,471 mg/kg 8.471 [16]
Cyanuric acid rat, oral 7,700 mg/kg 7.7 [17]
Cadmium sulfide rat, oral 7,080 mg/kg 7.08 [18]
Ethanol (Grain alcohol) rat, oral 7,060 mg/kg 7.06 [19]
Sodium isopropyl methylphosphonic acid (IMPA, metabolite of sarin) rat, oral 6,860 mg/kg 6.86 [20]
Melamine rat, oral 6,000 mg/kg 6 [17]
Methanol human, oral 810 mg/kg 0.81 [21]
Taurine rat, oral 5,000 mg/kg 5 [22]
Melamine cyanurate rat, oral 4,100 mg/kg 4.1 [17]
Fructose (fruit sugar) rat, oral 4,000 mg/kg 4 [23]
Sodium molybdate rat, oral 4,000 mg/kg 4 [24]
Sodium chloride (table salt) rat, oral 3,000 mg/kg 3 [25]
Paracetamol (acetaminophen) mouse, oral 338 mg/kg 0.338 [26]
Delta-9-tetrahydrocannabinol (THC) rat, oral 1270 mg/kg 1.27 [27]
Cannabidiol (CBD) rat, oral 980 mg/kg 0.98 [28]
Metallic Arsenic rat, oral 763 mg/kg 0.763 [29]
Ibuprofen rat, oral 636 mg/kg 0.636 [30]
Formaldehyde rat, oral 600–800 mg/kg 0.6 [31]
Solanine main alkaloid in the several plants in Solanaceae amongst them Solanum tuberosum rat, oral (2.8 mg/kg human, oral) 590 mg/kg 0.590 [32]
Alkyl dimethyl benzalkonium chloride (ADBAC) rat, oral
fish, immersion
aquatic invertebrates, immersion		 304.5 mg/kg
{0.28 mg/L}
{0.059 mg/L}		 0.3045
{0.00028}
{0.000059}		 [33]
Coumarin (benzopyrone, from Cinnamomum aromaticum and other plants) rat, oral 293 mg/kg 0.293 [34]
Psilocybin (from magic mushrooms) mouse, oral 280 mg/kg 0.280 [35]
Hydrochloric acid rat, oral 238–277 mg/kg 0.238 [36]
Ketamine rat, intraperitoneal 229 mg/kg 0.229 [37]
Aspirin (acetylsalicylic acid) rat, oral 200 mg/kg 0.2 [38]
Caffeine rat, oral 192 mg/kg 0.192 [39]
Arsenic trisulfide rat, oral 185–6,400 mg/kg 0.185–6.4 [40]
Sodium nitrite rat, oral 180 mg/kg 0.18 [41]
Methylenedioxymethamphetamine (MDMA, ecstasy) rat, oral 160 mg/kg 0.18 [42]
Uranyl acetate dihydrate mouse, oral 136 mg/kg 0.136 [43]
Dichlorodiphenyltrichloroethane (DDT) mouse, oral 135 mg/kg 0.135 [44]
Uranium mice, oral 114 mg/kg (estimated) 0.114 [45]
Bisoprolol mouse, oral 100 mg/kg 0.1 [46]
Cocaine mouse, oral 96 mg/kg 0.096 [47]
Cobalt(II) chloride rat, oral 80 mg/kg 0.08 [48]
Cadmium oxide rat, oral 72 mg/kg 0.072 [49]
Thiopental sodium (used in lethal injection) rat, oral 64 mg/kg 0.064 [50]
Demeton-S-methyl rat, oral 60 mg/kg 0.060 [51]
Methamphetamine rat, intraperitoneal 57 mg/kg 0.057 [52]
Sodium fluoride rat, oral 52 mg/kg 0.052 [53]
Pentaborane human, oral 50 mg/kg 0.05 [54]
Capsaicin mouse, oral 47.2 mg/kg 0.0472 [55]
Mercury(II) chloride rat, dermal 41 mg/kg 0.041 [56]
Vitamin D3 (cholecalciferol) rat, oral 37 mg/kg 0.037 [57]
Piperidine (from black pepper) rat, oral 30 mg/kg 0.030 [58]
Heroin (diamorphine) mouse, intravenous 21.8 mg/kg 0.0218 [59]
Lysergic acid diethylamide (LSD) rat, intravenous 16.5 mg/kg 0.0165 [60]
Arsenic trioxide rat, oral 14 mg/kg 0.014 [61]
Nicotine human, oral

mice, oral

 13–50 mg/kg (estimated)

3.3 mg/kg

 0.013–0.05

0.003

 [62]

[63]

Metallic Arsenic rat, intraperitoneal 13 mg/kg 0.013 [64]
Sodium cyanide rat, oral 6.4 mg/kg 0.0064 [65]
Hydrogen cyanide mouse, oral 3.7 mg/kg 0.0037 [66]
Chlorotoxin (CTX, from scorpions) mice 4.3 mg/kg 0.0043 [67]
Carfentanil rat, intravenous 3.39 mg/kg 0.00339 [68]
White phosphorus rat, oral 3.03 mg/kg 0.00303 [69]
Strychnine human, oral 1–2 mg/kg (estimated) 0.001–0.002 [70]
Cantharidin (from blister beetles) human, oral 500 µg/kg 0.0005
Aflatoxin B1 (from Aspergillus flavus mold) rat, oral 480 µg/kg 0.00048 [71]
Plutonium dog, intravenous 320 µg/kg 0.00032 [72]
Amatoxin (from Amanita phalloides mushrooms) rat 300-700 µg/kg 0.0007 [73]
Tetrodotoxin (TTX, from blue-ringed octopus) mice, oral 334 µg/kg 0.000334 [74]
Fentanyl monkey 300 µg/kg 0.0003 [75]
Bufotoxin (from Bufo toads) cat, intravenous 300 µg/kg 0.0003 [76]
Sarin mouse, subcutaneous injection 172 µg/kg 0.000172 [77]
Robustoxin (from Sydney funnel-web spider) mice 150 µg/kg 0.000150 [78]
VX human, oral, inhalation, absorption through skin/eyes 140 µg/kg (estimated) 0.00014 [79]
Venom of the Brazilian wandering spider rat, subcutaneous 134 µg/kg 0.000134 [80]
Aconitine main alkaloid in Aconitum napellus and related species rat, intraveneous 80 µg/kg 0.000080 [81]
Venom of the Inland Taipan (Australian snake) rat, subcutaneous 25 µg/kg 0.000025 [82]
Ricin (from castor oil plant) rat, intraperitoneal
rat, oral		 22 μg/kg
20–30 mg/kg		 0.000022
0.02		 [83]
2,3,7,8-Tetrachlorodibenzodioxin (TCDD, in Agent Orange) rat, oral 20 µg/kg 0.00002
CrTX-A (from box jellyfish venom) crayfish, intraperitoneal 5 µg/kg 0.000005 [84]
Latrotoxin (from widow spider venom) mice 4.3 µg/kg 0.0000043 [85]
Batrachotoxin (from poison dart frog) human, sub-cutaneous injection 2–7 µg/kg (estimated) 0.000002 [86]
Abrin (from rosary pea) mice, intravenously

human, inhalation

human, oral

0.7 µg/kg

3.3 µg/kg

10–1000 µg/kg

0.0000007

0.0000033

0.00001–0.001
Maitotoxin (from ciguateric fish) mouse, intraperitoneal 130 ng/kg 0.00000013 [87]
Polonium-210 human, inhalation 10 ng/kg (estimated) 0.00000001 [88]
Diphtheria toxin mice 10 ng/kg 0.00000001 [89]
Shiga toxin (from dysentery) mice 2 ng/kg 0.000000002 [89]
Tetanospasmin (tetanus toxin) mice 2 ng/kg 0.000000002 [89]
Botulinum toxin (Botox) human, oral, injection, inhalation 1 ng/kg (estimated) 0.000000001 [90]
Ionizing radiation human, irradiation 5 Gy [91]

Animal rights concerns

Animal-rights and animal-welfare groups, such as Animal Rights International,[92] have campaigned against LD50 testing on animals. Several countries, including the UK, have taken steps to ban the oral LD50, and the Organisation for Economic Co-operation and Development (OECD) abolished the requirement for the oral test in 2001 (see Test Guideline 401, Trends in Pharmacological Sciences Vol 22, February 22, 2001).

See also

Other measures of toxicity
  • TCID50 Tissue Culture Infective Dosage
  • EID50 Egg Infective Dosage
  • ELD50 Egg Lethal Dosage
  • Plaque forming units (pfu)

References
  1. Chemistry, International Union of Pure and Applied. "IUPAC Gold Book - absolute lethal dose (LD100)". goldbook.iupac.org. Retrieved 2019-07-01.
  2. Safety, Government of Canada, Canadian Centre for Occupational Health and. "What is a LD50 and LC50? : OSH Answers". www.ccohs.ca.
  3. "Allergan Receives FDA Approval for First-of-Its-Kind, Fully in vitro, Cell-Based Assay for BOTOX® and BOTOX® Cosmetic (onabotulinumtoxinA)". Allergan Web site. 24 June 2011. Archived from the original on 26 June 2011. Retrieved 2012-08-15.
  4. "In U.S., Few Alternatives To Testing On Animals". Washington Post. 12 April 2008. Retrieved 2011-06-26.
  5. REGISTRY OF TOXIC EFFECTS OF CHEMICAL SUBSTANCES (RTECS)
    COMPREHENSIVE GUIDE TO THE RTECS     Archived 2013-05-16 at the Wayback Machine
  6. Ernest Hodgson (2004). A Textbook of Modern Toxicology. Wiley-Interscience (3rd ed.).
  7. "Material Safety Data Sheet Water MSDS". Section 11: Toxicological Information for the LD50 verification. Archived from the original on 2012-09-02. Retrieved 2012-05-09.
  8. "Safety (MSDS) data for sucrose". ox.ac.uk.
  9. "Safety (MSDS) data for glucose" (PDF). utoronto.ca. Archived from the original (PDF) on 2017-01-01. Retrieved 2016-12-31.
  10. Walker R, Lupien JR (April 2000). "The safety evaluation of monosodium glutamate". The Journal of Nutrition. 130 (4S Suppl): 1049S–52S. doi:10.1093/jn/130.4.1049S. PMID 10736380.
  11. Toskulkao C, Chaturat L, Temcharoen P, Glinsukon T (1997). "Acute toxicity of stevioside, a natural sweetener, and its metabolite, steviol, in several animal species". Drug and Chemical Toxicology. 20 (1–2): 31–44. doi:10.3109/01480549709011077. PMID 9183561.
  12. "Safety (MSDS) data for ascorbic acid". Oxford University. 2005-10-09. Archived from the original on 2007-02-09. Retrieved 2007-02-21.
  13. "PubChem - Glyphosate-isopropylammonium". Retrieved 2019-01-17.
  14. "Safety (MSDS) data for Lactose" (PDF). Archived from the original (PDF) on 2016-08-03. Retrieved 2016-12-31.
  15. https://www.spectrumchemical.com/MSDS/A6051.pdf
  16. "Safety (MSDS) data for urea". 2015-03-06. Section 11: Toxicological Information for the LD50 verification. Archived from the original on 2015-03-01. Retrieved 2015-03-06.
  17. A.A. Babayan, A.V.Aleksandryan, "Toxicological characteristics of melamine cyanurate, melamine and cyanuric acid", Zhurnal Eksperimental'noi i Klinicheskoi Meditsiny, Vol.25, 345–9 (1985). Original article in Russian.
  18. Advanced Search – Alfa Aesar – A Johnson Matthey Company Archived 2015-07-24 at the Wayback Machine. Alfa.com. Retrieved on 2013-07-17.
  19. "Safety (MSDS) data for ethyl alcohol". ox.ac.uk.
  20. Mecler, Francis J. (May 1981). Mammalian Toxological Evaluation of DIMP and DCBP (Phase 3 – IMPA) (Final report ed.). Litton Bionetics, Inc. The oral LD50 values for the test material, IMPA, were 7650 and 6070 mg/kg for male and female rats, respectively.
  21. "Methanol Poisoning Overview". antizol.com.
  22. "Safety data for taurine" (PDF). scbt.com.
  23. "Safety (MSDS) data for fructose". sciencelab.com. Archived from the original on 2017-07-02. Retrieved 2016-12-31.
  24. "Safety (MSDS) data for sodium molybdate". ox.ac.uk.
  25. "Safety (MSDS) data for sodium chloride". ox.ac.uk.
  26. Safety (MSDS) data for paracetamol
  27. Rosenkrantz, Harris; Heyman, Irwin A.; Braude, Monique C. (1974). "Inhalation, parenteral and oral LD50 values of Δ9-tetrahydrocannabinol in Fischer rats". Toxicology and Applied Pharmacology. 28 (1): 18–27. doi:10.1016/0041-008X(74)90126-4. PMID 4852457.
  28. "MSDS of CBD" (PDF). chemblink.com. Archived from the original (PDF) on 2016-12-26. Retrieved 2016-12-26.
  30. "IBUPROFEN - National Library of Medicine HSDB Database". toxnet.nlm.nih.gov.
  31. "Formaldehyde SIDS Initial Assessment Report" (PDF). inchem.org. Archived from the original (PDF) on 2018-06-13. Retrieved 2016-12-26.
  32. "SOLANINE - National Library of Medicine HSDB Database". toxnet.nlm.nih.gov.
  33. Frank T. Sanders, ed. (August 2006). Reregistration Eligibility Decision for Alkyl Dimethyl Benzyl Ammonium Chloride (ADBAC) (PDF) (Report). U.S. Environmental Protection Agency Office of Prevention, Pesticides, and Toxic Substances. p. 114. Archived from the original (PDF) on 2009-10-24. Retrieved 2009-03-31.
  34. Coumarin Material Safety Data Sheet (MSDS) Archived 2004-10-21 at the Wayback Machine
  35. Rumack, Barry H.; Spoerke, David G. (27 September 1994). Handbook of Mushroom Poisoning: Diagnosis and Treatment. CRC Press. ISBN 9780849301940 – via Google Books.
  36. "Safety (MSDS) data for hydrochloric acid". fishersci.com.
  37. "Ketamine" (PDF). nih.gov.
  38. "Safety (MSDS) data for acetylsalicylic acid". ox.ac.uk.
  39. https://chem.nlm.nih.gov/chemidplus/sid/0000302272%5B%5D
  40. "Material Safety Data Sheet – Spent Metal Catalyst" (PDF). Archived from the original (PDF) on 2011-09-28.
  41. "Safety (MSDS) data for sodium nitrite". ox.ac.uk.
  42. Gable RS (September 2004). "Acute toxic effects of club drugs". Journal of Psychoactive Drugs. 36 (3): 303–13. doi:10.1080/02791072.2004.10400031. PMID 15559678.
  43. "Chemical toxicity of uranium" (PDF). who.int.
  44. Hayes WJ (21 December 2013) [1959]. "Pharmacology and toxicology of DDT". In Müller P, Simmons SW (eds.). DDT: The Insecticide Dichlorodiphenyltrichloroethane and Its Significance / Das Insektizid Dichlordiphenyltrichloräthan und Seine Bedeutung: Human and Veterinary Medicine. 2. Springer-Verlag. pp. 9–247. ISBN 978-3-0348-6809-9.
  45. http://www.who.int/ionizing_radiation/pub_meet/en/Depluranium4.pdf
  46. "Bisoprolol". www.drugbank.ca.
  47. "Cocaine". www.drugbank.ca.
  48. "Safety (MSDS) data for cobalt (II) chloride". ox.ac.uk.
  49. Safety (MSDS) data for cadmium oxide
  50. Pubchem. "Thiopental sodium". pubchem.ncbi.nlm.nih.gov.
  51. "Demeton-s-methyl". September 1995.
  52. Kiyatkin EA, Sharma HS (2009). Acute methamphetamine intoxication: brain hyperthermia, blood-brain barrier, brain edema, and morphological cell abnormalities. Int Rev Neurobiol. International Review of Neurobiology. 88. pp. 65–100. doi:10.1016/S0074-7742(09)88004-5. ISBN 9780123745040. PMC 3145326. PMID 19897075.
  53. "SODIUM FLUORIDE". hazard.com.
  54. "Pentaborane chemical and safety data" (PDF). noaa.gov.
  55. "Capsaicin Material Safety Data Sheet". sciencelab.com. 2007. Archived from the original (PDF) on 2007-09-29. Retrieved 2007-07-13.
  56. http://www.sigmaaldrich.com/catalog/DisplayMSDSContent.doc
  57. "MSDS for cholecalciferol crystalline" (PDF). hmdb.ca.
  58. "MSDS for piperidine (pepper)". fishersci.com.
  59. "Diamorphine (PIM 261F, French)". www.inchem.org.
  60. Erowid LSD (Acid) Vault : Fatalities / Deaths. Erowid.org. Retrieved on 2013-07-17.
  61. "Safety (MSDS) data for arsenic trioxide". ox.ac.uk.
  62. Mayer B (January 2014). "How much nicotine kills a human? Tracing back the generally accepted lethal dose to dubious self-experiments in the nineteenth century". Archives of Toxicology. 88 (1): 5–7. doi:10.1007/s00204-013-1127-0. PMC 3880486. PMID 24091634.
  63. Mayer B (January 2014). "How much nicotine kills a human? Tracing back the generally accepted lethal dose to dubious self-experiments in the nineteenth century". Archives of Toxicology. 88 (1): 5–7. doi:10.1007/s00204-013-1127-0. PMC 3880486. PMID 24091634.
  64. "Safety (MSDS) data for metallic arsenic". ox.ac.uk.
  65. "Safety (MSDS) data for sodium cyanide". ox.ac.uk.
  66. "Safety (MSDS) data for hydrogen cyanide" (PDF). orica.com. Archived from the original (PDF) on 2016-12-26. Retrieved 2016-12-26.
  67. "Chlorotoxin: A Helpful Natural Scorpion Peptide to Diagnose Glioma and Fight Tumor Invasion".
  68. "Critical Review Carfentanil" (PDF). Retrieved 2019-01-31.
  69. "Hexachloroethane" (PDF). Retrieved 2014-01-03.
  70. INCHEM: Chemical Safety Information from Intergovernmental Organizations: Strychnine.
  71. "Safety (MSDS) data for aflatoxin B1". ox.ac.uk.
  72. George L. Voelz and Ileana G. Buican (2000). "Plutonium and Health — How great is the risk?" (PDF). Los Alamos Science (26): 74–89.
  73. Kastin, Abba; Kastin, Abba J. (28 April 2011). Handbook of Biologically Active Peptides. Elsevier. ISBN 9780080463797 – via Google Books.
  74. "Material Safety Data Sheet Tetrodotoxin ACC# 01139". Acros Organics N.V.
  75. "Fentanyl". www.drugbank.ca.
  76. "nih.gov Datasheet for Bufotoxin".
  77. Inns RH, Tuckwell NJ, Bright JE, Marrs TC (July 1990). "Histochemical demonstration of calcium accumulation in muscle fibres after experimental organophosphate poisoning". Human & Experimental Toxicology. 9 (4): 245–50. doi:10.1177/096032719000900407. PMID 2390321.
  78. Sheumack DD, Baldo BA, Carroll PR, Hampson F, Howden ME, Skorulis A (1984). "A comparative study of properties and toxic constituents of funnel web spider (Atrax) venoms". Comparative Biochemistry and Physiology. C, Comparative Pharmacology and Toxicology. 78 (1): 55–68. doi:10.1016/0742-8413(84)90048-3. PMID 6146485.
  79. Munro, N. (Jan 1994). "Toxicity of the organophosphate chemical warfare agents GA, GB, and VX: implications for public protection". Environmental Health Perspectives. 102 (1): 18–38. doi:10.1289/ehp.9410218. PMC 1567233. PMID 9719666.
  80. Venomous Animals and their Venoms, vol. III, ed. Wolfgang Bücherl and Eleanor Buckley
  81. "ACONITINE - National Library of Medicine HSDB Database". toxnet.nlm.nih.gov.
  82. LD50 for various snakes Archived 2012-02-01 at the Wayback Machine. Seanthomas.net. Retrieved on 2013-07-17.
  83. EFSA – Scientific Opinion of the CONTAM Panel: Ricin (from Ricinus communis) as undesirable substances in animal feed [1] - Scientific Opinion of the Panel on Contaminants in the Food Chain. Efsa.europa.eu. Retrieved on 2013-07-17.
  84. Nagai H (2003). "Recent Progress in Jellyfish Toxin Study". Journal of Health Science. 49 (5): 337–340. doi:10.1248/jhs.49.337. ISSN 1344-9702.
  85. "Archived copy". Archived from the original on 2016-12-26. Retrieved 2016-12-26.CS1 maint: archived copy as title (link)
  86. "Brief Review of Natural Nonprotein Neurotoxins". asanltr.com.
  87. Yokoyama A, Murata M, Oshima Y, Iwashita T, Yasumoto T (August 1988). "Some chemical properties of maitotoxin, a putative calcium channel agonist isolated from a marine dinoflagellate". Journal of Biochemistry. 104 (2): 184–7. doi:10.1093/oxfordjournals.jbchem.a122438. PMID 3182760.
  88. Topic 2 Toxic Chemicals and Toxic Effects Archived 2007-09-29 at the Wayback Machine
  89. "Archived copy" (PDF). Archived from the original (PDF) on 2015-04-12. Retrieved 2016-12-26.CS1 maint: archived copy as title (link)
  90. Fleming DO, Hunt DL (2000). Biological Safety: principles and practices. Washington, DC: ASM Press. p. 267. ISBN 978-1-55581-180-8.
  91. Koelzer, Winfried (2013). "Lethal dose". www.euronuclear.org. Archived from the original on 2018-08-04. Retrieved 2018-09-15.
  92. Thirty-Two Years of Measurable Change Archived 2007-02-11 at the Wayback Machine
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