Toxicity
Sam K., Jose A, Alberto F.
What is the meaning of the word toxic you ask? Toxic means when a substance can harm an organism, and there are multiple ways to measure the toxicity of a substance. One way they measure a substances toxicity is by orally giving the tests subject (mostly rats and mice) pure versions of the substance. Also, they will have the rats or mice inhale the substance. Before they test it, they see how much of the substance they use. If half of the test subjects die from a substance orally, the amount used will be the LD50 for that specific substance. If half of the test subjects die from the substance being inhaled, the concentration used will be the LC50 for that substance.
The LD50 is an important measurement for toxicity. A substance's LD50 is the amount needed to kill half of the animals exposed, expressed in mass per kg of body weight. A similar measurement is the LC50, which is the concentration of a toxin in air or water that does the same thing. These along with other units can be used to find out about how toxic a substance is to humans. This is important because then if there is a spill responders can judge what protective gear they need to clean it up. Another use of an LD50 is in a material safety data sheet, which uses this along with other stats like LDLO and LD1 to judge the relative danger of chemicals.
The LD50 is an important measurement for toxicity. A substance's LD50 is the amount needed to kill half of the animals exposed, expressed in mass per kg of body weight. A similar measurement is the LC50, which is the concentration of a toxin in air or water that does the same thing. These along with other units can be used to find out about how toxic a substance is to humans. This is important because then if there is a spill responders can judge what protective gear they need to clean it up. Another use of an LD50 is in a material safety data sheet, which uses this along with other stats like LDLO and LD1 to judge the relative danger of chemicals.
Definitions
LD50 - Amount of a substance needed to kill 50% of the animals exposed
LC50 - Concentration of a substance in air or water needed to kill 50% of animals exposed after a short period of time.
Toxic - When a substance can harm the environment around it
LDLO - Least amount of a substance needed to cause ill effects
LD1 - Amount of a substance needed to kill 1% of animals exposed
Sources
LD50 - Amount of a substance needed to kill 50% of the animals exposed
LC50 - Concentration of a substance in air or water needed to kill 50% of animals exposed after a short period of time.
Toxic - When a substance can harm the environment around it
LDLO - Least amount of a substance needed to cause ill effects
LD1 - Amount of a substance needed to kill 1% of animals exposed
Sources
- Living By Chemistry Textbook, pages 375-377
- http://www.ccohs.ca/oshanswers/chemicals/ld50.html
- http://www.rsc.org/pdf/ehsc/ld50.pdf