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Median lethal dose. In toxicology, the median lethal dose, LD50 (abbreviation for " lethal dose, 50%"), LC50 (lethal concentration, 50%) or LCt50 is a toxic unit that measures the lethal dose of a given substance. [1] The value of LD 50 for a substance is the dose required to kill half the members of a tested population after a specified test ...
Lethal dose. In toxicology, the lethal dose (LD) is an indication of the lethal toxicity of a given substance or type of radiation. Because resistance varies from one individual to another, the "lethal dose" represents a dose (usually recorded as dose per kilogram of subject body weight) at which a given percentage of subjects will die.
Sale of Grade 3 diesel at retail outlets is optional until 2008. At the time the regulation was published, the sulfur limits amounted to 3000 ppm for Grade 1, 1500/2500 ppm (depending on the area) for Grade 2, and 500 ppm for Grade 3. Sulfur limit reductions occur in 2008, 2009, 2011, and 2016.
In environmental chemistry, the chemical oxygen demand (COD) is an indicative measure of the amount of oxygen that can be consumed by reactions in a measured solution. It is commonly expressed in mass of oxygen consumed over volume of solution, which in SI units is milligrams per liter (mg / L). A COD test can be used to quickly quantify the ...
Parts-per notation is often used describing dilute solutions in chemistry, for instance, the relative abundance of dissolved minerals or pollutants in water. The quantity "1 ppm" can be used for a mass fraction if a water-borne pollutant is present at one-millionth of a gram per gram of sample solution. When working with aqueous solutions, it ...
4 clo − 2 + 2 h 2 so 4 → 2 clo 2 + hclo 3 + 2 so 2− 4 + h 2 o + hcl All three methods can produce chlorine dioxide with high chlorite conversion yield. Unlike the other processes, the chlorite–sulfuric acid method is completely chlorine-free, although it suffers from the requirement of 25% more chlorite to produce an equivalent amount ...
The LD 50 for oral toxicity is less than 500 mg/kg for dogs, rabbits, or mice; the minimum lethal human dose was cited as 140 mg/kg. [49] The Agency for Toxic Substances and Disease Registry (ATSDR), U.S. Department of Health and Human Services states the fatal dose for ingestion of phenol is from 1 to 32 g.
Mesitylene or 1,3,5-trimethylbenzene is a derivative of benzene with three methyl substituents positioned symmetrically around the ring. The other two isomeric trimethylbenzenes are 1,2,4-trimethylbenzene (pseudocumene) and 1,2,3-trimethylbenzene (hemimellitene). All three compounds have the formula C 6 H 3 (CH 3) 3, which is commonly ...