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Toxicity is the degree to which a chemical substance or a particular mixture of substances can damage an organism. [1] Toxicity can refer to the effect on a whole organism, such as an animal, bacterium, or plant, as well as the effect on a substructure of the organism, such as a cell (cytotoxicity) or an organ such as the liver (hepatotoxicity).
Highly Toxic: a gas that has a LC 50 in air of 200 ppm or less. [2] NFPA 704: Materials that, under emergency conditions, can cause serious or permanent injury are given a Health Hazard rating of 3. Their acute inhalation toxicity corresponds to those vapors or gases having LC 50 values greater than 1,000 ppm but less than or equal to 3,000 ppm ...
This is the list of extremely hazardous substances defined in Section 302 of the U.S. Emergency Planning and Community Right-to-Know Act (42 U.S.C. § 11002).The list can be found as an appendix to 40 CFR 355. [1]
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, LD 50 ...
Therefore, a common characteristic of toxic metals is the chronic nature of their toxicity. This is particularly notable with radioactive heavy metals such as radium, which imitates calcium to the point of being incorporated into human bone, although similar health implications are found in lead or mercury poisoning.
The Amanita muscaria mushroom, an iconic toxic mushroom. A toxin is a naturally occurring poison [1] produced by metabolic activities of living cells or organisms. [2] They occur especially as proteins, often conjugated. [3] The term was first used by organic chemist Ludwig Brieger (1849–1919), [4] derived from toxic.
Presently, DDT has been labeled as a possible human carcinogen based on animal liver tumor studies. [20] DDT toxicity on humans have been associated with dizziness, tremors, irritability, and convulsions. Chronic toxicity has led to long term neurological and cognitive issues. [21]
Acute toxicity is distinguished from chronic toxicity, which describes the adverse health effects from repeated exposures, often at lower levels, to a substance over a longer time period (months or years). It is widely considered unethical to use humans as test subjects for acute (or chronic) toxicity research.