Toxicity of phosphorus

G. B. Quistad, N. Zhang, S. E. Sparks, J. E. Casida, Phosphoacetylcholinesterase Toxicity of Phosphorus Oxychloride to Mammals and Insects That Can be Attributed to Selective Phosphorylation of Acetylcholinesterase by Phosphorodichloridic Acid , Chem. Res. Toxicol. 2000, 13, 652-657. 

Despite tlie high toxicity of phosphorus, it was formerly a widely used pharmaceutical, happily in quite small doses (though happier would have been no dose at all). It was recommended for nervous breakdown, depression, migraine, epilepsy, stroke, pneumonia, alcoholism, tuberculosis, cholera, and cataracts. " Free Phosphorus in Medicine, published in 1874, extolled its benefits. By 1930, elemental phosphorus was eliminated from the practice of medicine. That is entirely appropriate since it has absolutely no medical benefits. 

Weeks MH, Musselman NP, Yevich PP, et al Acute vapor toxicity of phosphorus oxychloride, phosphorus trichloride and methyl phos-phonic dichloride. Am Ind Hyg Assoc J 25 470-475, 1964... 

There is very little information on the toxicity of phosphorus pentasulfide. Irritancy of the respiratory tract would be expected because the substance is rapidly hydrolyzed to phosphoric acid and hydrogen sulfide pulmonary irritation is expected at concentrations of lOmg/m ... 

Quistad, G.B. et al., Toxicity of phosphorus oxychloride to mammals and insects that can be attributed to selective phosphorylation of acetylcholinesterase by phosphorodichloridic acid, Chem. Res. Toxicol., 13, 652-657, 2000. 

Ballantyne B (1998). Acute inhalation toxicity of phosphorus pentoxide smoke. Toxic Sub Mech, 17, 251-266. 

Table 13.3 Toxicity of phosphorus insecticides to mammals and insects. (LD50 in p.p.m. w/w)...

A.F. Childs and H. Coates, The toxicity of phosphorus compounds, in Mellor s Comprehensive Treatise on Inorganic and Theoretical Chemistry, Vol. 8, Supp. 3, Longmans, London, 1971. 

Arsenic exists as grey, yellow and black forms of differing physical properties and susceptibilities towards atmospheric oxygen. The general chemistry is similar to that of phosphorus but whereas phosphorus is non-metallic, the common form of arsenic is metallic. Traces of arsenides may be present in metallic residues and drosses these may yield highly toxic arsine, ASH3, with water. 

Substances which have a deleterious effect on the taste and/or smell of the products for human consumption derived from the aquatic environment Toxic or persistent organic compounds of silicon Inorganic compounds of phosphorus and elemental phosphorus Non-persistent mineral oils and hydrocarbons of petroleum origin Cyanides, fluorides... 

Factors that can predispose patients to developing metabolic bone disease include deficiencies of phosphorus, calcium, and vitamin D vitamin D and/or aluminum toxicity amino acids and hypertonic dextrose infusions chronic metabolic acidosis corticosteroid therapy and lack of mobility.35,39 Calcium deficiency (due to decreased intake or increased urinary excretion) is one of the major causes of metabolic bone disease in patients receiving PN. Provide adequate calcium and phosphate with PN to improve bone mineralization and help to prevent metabolic bone disease. Administration of amino acids and chronic metabolic acidosis also appear to play an important role. Provide adequate amounts of acetate in PN admixtures to maintain acid-base balance. 

The toxic organic phosphorus compounds act as powerful inhibitors of cholinesterase, an enzyme found predominantly in the nervous tissue of animals, including insects. This enzyme hydrolyzes acetylcholine, which plays an essential role in the transmission of nerve impulses. The toxicity of compounds in this series can be largely accounted for on the basis of their anticholinesterase activity (7,8,12,14, SI). 

In a few instances, the introduction of fluorine into certain compounds containing oxygen, nitrogen, or phosphorus increases the toxicity of such compounds to a spectacular degree. 

The only element that was discovered in body fluids (urine). This is plausible, as P plays a main role in all life processes. It is one of the five elements that make up DNA (besides C, H, N, and 0 evolution did not require anything else to code all life). The P-O-P bond, phosphoric acid anhydride, is the universal energy currency in cells. The skeletons of mammals consists of Ca phosphate (hydroxylapatite). The element is encountered in several allotropic modifications white phosphorus (soft, pyrophoric P4, very toxic), red phosphorus (nontoxic, used to make the striking surface of matchboxes), black phosphorus (formed under high pressures). Phosphates are indispensable as fertilizer, but less desirable in washing agents as the waste water is too concentrated with this substance (eutrophication). It has a rich chemistry, is the basis for powerful insecticides, but also for warfare agents. A versatile element. 

Caution. Since many of the fluoro derivatives of the oxygen acids of phosphorus are known10 to he extremely TOXIC and since detailed and reliable toxicity data on all the compounds considered here are not available, all these fluorophosphine derivatives should be handled as though they were highly toxic materials. 

Kimmerle, G., A. Een, P. Groning, and J. Thyssen. "Acute Toxicity of Bicyclic Phosphorus Esters." Archivfuer Toxikologie 35 (1976) 149-52. 

With the use of the rapid fire detection and water deluge, there was no mass fire and the mix was ckrped into water for continued fire suppression. Any fire with RP results in the formation of white phosphorus (WP). WP must be covered with water since it ignites spontaneously when exposed to air. Processing studies were conducted to determine the best methods for pollution abatement since UP/water mixtures are toxic at 29 pob for blue gill bream and since high levels of phosphorus [reported as total phosphorus may not be durped into the environment. 

The toxic impurities of phosphorus ores are conserved in phosphorus fertilizers produced from these ores, and finally they are accumulated in the agroecosystems (see Chapter 13). These pollutants can enter into biogeochemical food webs and increase the ecological risk especially under acid soils distributed in many regions of the World (Europe, Asia and North and South America). 

Table VI. Effect of Zinc Toxicity on Phosphorus Retention in ...

The data presented in this paper indicate that excess levels (0.75%) of dietary zinc result in decreases in the bioavailability of calcium and phosphorus in rats and interfere with normal bone mineralization. High dietary levels of calcium or zinc appeared to cause a shift in the excretion of phosphorus from the urine to the feces, while the presence of extra phosphorus tended to keep the pathway of phosphorus excretion via the urine. The presence of large amounts of phosphorus in the Intestinal tract due to high intakes of zinc would increase the possibility of the formation of insoluble phosphate salts with various cations, including calcium, which may be present. A shift in phosphorus excretion from the feces to the urine, however, could result in an environmental condition within the system which would tend to increase the bioavailability of cations to the animal. The adverse effect of zinc toxicity on calcium and phosphorus status of young rats could be alleviated with calcium and/or phosphorus supplements. 

This may be the reason why silicon is essential, namely that it keeps aluminium in a non-toxic form as aluminium silicate. While silicon is required as a trace element in most animals, in plants, particularly grasses, and in many unicellular organisms, such as diatoms4, it is a major structural element. The importance of phosphorus and sulfur is obvious, the latter often associated with iron in an important family of proteins that contains iron-sulfur clusters. 

As a matter of interest, we obtained a compound, diethyl phosphorofluoridite (IX), of a lower state of oxidation than the corresponding phosphorofluoridate by the action of phosphorus dichlorofluoride on ethyl alcohol. The new compound, unlike the phosphorofluoridate, was readily hydrolysed by water, was relatively non-toxic and did not produce myosis.1... 

Di 2 fluoroethyl phosphorofluoridate (XVIII) was prepared with the idea of combining the toxic principles of the fluoro-aoetates and of the phosphorofluoridates. It was readily obtained by the action of phosphorus oxydichlorofluoride on... 

Among many esters, di w propyl and diisopropyl phosphoro-fluoridate were prepared by the action of phosphorus oxy-dichlorofluoride on ra-propyl and isopropyl alcohol respectively. The n-ester was less toxic and possessed only feeble myotic... 

In view of the rapid toxic action and myotic effect of the dialkyl phosphorofluoridates and of the high toxicity of some of the phosphorodiamidic fluorides, we prepared2 and examined a hybrid molecule containing the essential features of each type of compound. The first to be examined was ethyl phenyl-phosphoramidofluoridate (VII). One mol. of phosphorus oxy-dichlorofluoride was added to 1 mol. of ethyl alcohol, and the resulting ethyl phosphorofluoridochloridate (which it was not necessary to isolate) was treated with aniline. 

Most of our examples are chosen because they have, or may have, some bearing directly or indirectly on the main theme of the monograph, namely, the study of certain compounds of phosphorus and fluorine noted for their striking toxic action. 

An attempt to prepare 1 -bromo-2-fluoroethane by the partial fluorination of ethylene dibromide by means of antimony trifluoride was not very successful. The compound was best prepared by the action of phosphorus tribromide on F.E.A. The compound was relatively non-toxic and the bromine atom rather unreactive, but considerably more reactive than the chlorine atom in chlorofluoroethane. For example, bromofluoroethane was readily converted by means of potassium thiocyanate into 2-fluoroethyl thiocyanate. As a lethal inhalant the toxicity of the thiocyanate was inferior to that of M.F.A. Toxicity by injection, however, appeared to be higher. 

The synthesis of a lethal or toxic substance from a less toxic or non-toxic substance in vivo is also observed among esters of phosphorus (see p. 173). 

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