The toxicity of any one material varies from one species to another. LD50 is the amount of a substance that causes the death of 50% of a group of test organisms. This provides crucial information on the toxic nature of various substances for which no other toxicology data is available. 

This information serves several purposes in research, including but not limited to: 

• Estimating safe acute doses for various species
• Determining the dose that will be lethal or produce serious toxicological in different species when administered in a single dose or in multiple doses over a specific period of time
• Determining potential target organs that should be scrutinized
• Determining appropriate dosage for multiple-dose toxicity studies