Editing Median lethal dose (section)

== Limitation ==
As a measure of toxicity, LD<sub>50</sub> 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.<ref name="ReferenceA">Ernest Hodgson (2004). ''A Textbook of Modern Toxicology''. Wiley-Interscience (3rd ed.).{{page needed|date=January 2014}}</ref>

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 [[Health effects of chocolate#Non-human animals|toxic to many animals]]. When used to test [[venom]] from venomous creatures, such as [[snake]]s, LD<sub>50</sub> results may be misleading due to the physiological differences between mice, rats, and humans. Many [[venomous snake]]s are specialized predators on mice, and their venom may be adapted specifically to incapacitate mice; and [[mongoose]]s may be exceptionally resistant. While most [[mammal]]s have a very similar physiology, LD<sub>50</sub> results may or may not have equal bearing upon every mammal species, such as humans, etc.