Phosphorus poisoning

The relatively non-poisonous red phosphorus was discovered in 1845 (Anton Schrotter in Vienna) and had been used since 1851-1852 (some sources say the Paris Exhibition of 1855), either in the match itself or within the material of the surface upon which the match was rubbed ("safety matches"). However, "friction matches" incorporating white phosphorus continued to be made for a least another half-century and it wasn t until the reatisation, in 1898 (Sevene and Cahen in France), that the non-poisonous phosphorus sesquisulphide (P4S3 previously discovered by Berzelius) could be used successfully as a substitute, that an agreement (eventually in Europe, the "Berne Convention 1906" in USA, the "Esch" law and "Match Act" of 1912) finally put an end to the use of white phosphorus in the match industry. 

Phosphine is a colourless gas at room temperature, boiling point 183K. with an unpleasant odour it is extremely poisonous. Like ammonia, phosphine has an essentially tetrahedral structure with one position occupied by a lone pair of electrons. Phosphorus, however, is a larger atom than nitrogen and the lone pair of electrons on the phosphorus are much less concentrated in space. Thus phosphine has a very much smaller dipole moment than ammonia. Hence phosphine is not associated (like ammonia) in the liquid state (see data in Table 9.2) and it is only sparingly soluble in water. 

It is very poisonous, 50 mg constituting an approximate fatal dose. Exposure to white phosphorus should not exceed 0.1 mg/ms (8-hour time-weighted average - 40-hour work week). White phosphorus should be kept under water, as it is dangerously reactive in air, and it should be handled with forceps, as contact with the skin may cause severe burns. 

Rhenium catalysts are exceptionally resistant to poisoning from nitrogen, sulfur, and phosphorus, and are used for hydrogenation of fine chemicals. 

Phosphorus(III) Oxide. Phosphoms(III) oxide [12440-00-5] the anhydride of phosphonic acid, is formed along with by-products such as phosphoms pentoxide and red phosphoms when phosphoms is burned with less than stoichiometric amounts of oxygen (62). Phosphoms(III) oxide is a poisonous, white, wax-like, crystalline material, which has a melting point of 23.8°C and a boiling point of 175.3°C. When added to hot water, phosphoms(III) oxide reacts violentiy and forms phosphine, phosphoric acid, and red phosphoms. Even in cold water, disproportionation maybe observed if the oxide is not well agitated, resulting in the formation of phosphoric acid and yellow or orange poorly defined polymeric lower oxides of phosphoms (LOOP). 

White phosphorus. This element burns in air and can produce severe thermal and chemical burns. It may reignite on drying. After washing, rapid but brief treatment with copper sulphate (to avoid systemic absorption and copper poisoning) is used to convert the phosphorus to copper phosphide which is then removed Hydrogen fluoride. This can form painful but delayed necrosis. Treat with calcium gluconate locally and monitoring of serum calcium levels, with administration of calcium where necessary... 

In catalytic incineration, there are limitations concerning the effluent streams to be treated. Waste gases with organic compound contents higher than 20% of LET (lower explosion limit) are not suitable, as the heat content released in the oxidation process increases the catalyst bed temperature above 650 °C. This is normally the maximum permissible temperature to which a catalyst bed can be continuously exposed. The problem is solved by dilution-, this method increases the furnace volume and hence the investment and operation costs. Concentrations between 2% and 20% of LET are optimal, The catalytic incinerator is not recommended without prefiltration for waste gases containing particulate matter or liquids which cannot be vaporized. The waste gas must not contain catalyst poisons, such as phosphorus, arsenic, antimony, lead, zinc, mercury, tin, sulfur, or iron oxide.(see Table 1.3.111... 

Rokosz, M.J., Chen, A.E., Lowe-Ma, C.K. et al. (2001) Characterization of phosphorus-poisoned automotive exhaust catalysts, Appl. Catal. B Environ., 33, 205. 

Degradation of poisoning phosphite [27] may lead to the formation of an aldehyde acid, as shown in Equation 2.8. The concentration of aldehyde acid and phosphorus or phosphoric acids should be monitored and controlled to minimize losses of the desired catalyst modifying ligand. 

But arsenic is more subtle a poison than simply a reducing or oxidizing agent. Arsenic is a metalloid from Group V(B) of the periodic table, immediately below the elements nitrogen and phosphorus, both of which are vital for health. 

The first time the body realizes that arsenic has been incorporated is when the redox activity (as above) proceeds at potentials when nitrogen or phosphorus are inert. By the time we detect the arsenic poisoning (i.e. we feel unwell), it is generally too late, since atoms of arsenic are covalently bound within body tissue and cannot just be flushed out or treated with an antidote. The arsenic sequesters electrons that might otherwise be involved in other relay cycles, which is a concurrent kinetic process see Figure 8.16. 

As can be seen from the results in Table V, fluoride levels in plasma, liver and kidney increased 3 to 8 times but there was no significant effect on the calcium or phosphorus content, although the kidney Ca level in fluoride treated rats was 40 higher than in the controls. Whereas the normal exposure to fluoride from air, food and water did not cause any increase in soft tissue levels, more than ten times the normal levels in soft tissues, including liver and kidney, were found in human fatalities due to fluoride poisoning (15). 

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