Phosphorus smoke from

This statement was prepared to give you information about white phosphorus and white phosphorus smoke and to emphasize the human health effects that may result from exposure to it. The Environmental Protection Agency (EPA) identifies the most serious hazardous waste sites as in the nation. These sites make up the National Priorities List (NPL) and are the sites targeted for long-term federal clean-up activities. White phosphorus has been found in at least 77 of 1,430 current or former NPL sites. However, the total number of NPL sites evaluated is not known. As more sites are evaluated, the number of sites at which white phosphorus is found may increase. This is important because exposure to white phosphorus may harm you and because these sites are sources of human exposure to white phosphorus. 

In water with low oxygen, white phosphorus may react with water to form a compound called phosphine. Phosphine is a highly toxic gas and quickly moves from water to air. Phosphine in air is changed to less harmful chemicals in less than a day. In water, white phosphorus builds up slightly in the bodies of fish. The other chemicals in white phosphorus smoke are mainly changed to relatively harmless chemicals in water and soil. White phosphorus may stay in soil for a few days before it is changed to less harmful chemicals. However, in deeper soil and the... 

The toxicokinetics of white phosphorus smoke are likewise unknown. White phosphorus smoke is primarily oxides and acids of phosphorus, with some residual unbumt white phosphorus (refer to Chapter 3 for a detailed description of the composition of white phosphorus smoke). The fates of airborne white phosphorus, and the phosphorus oxides and phosphorus-containing acids originating from the combustion of white phosphorus, are largely unknown. 

White Phosphorus Smoke. There is limited information on the toxicity of white phosphoms smoke. Based on this information, the respiratory tract appears to be the most sensitive target. Because white phosphoms smoke contains a number of phosphoms compounds and a small amount of white phosphoms, the toxicity of white phosphoms smoke cannot be extrapolated from human and animal studies involving exposure to white phosphoms. 

Other additional studies or pertinent information which lend support to this MRL Although a 5-minute exposure duration is usually too brief to consider for MRLs and expanding over a 24-hour period would result in an exposure level of 0.6 mg/m3, further experiments indicated that exposure for longer durations would result in more severe effects. In the field, white phosphorus smoke was generated at 0.1 mg/m3 to protect soldiers from detection. In addition the OSHA PEL is 0.1 mg/m3. Therefore, expanding the 5-minute duration over 24 hours is reasonable. 

While the vapors of white pliosphonis are 4 xceedingly toxi<, these apors are so quickly oxidized to phosphoru. jKuitoxide and phosphoric acid as to be harmless to men atid animals in ordinaiy 6 4d ro < cntra-(itms. There is some difference of opinion as to the physiological effect of fihosphorus smoke because of the possibility of the continued presence of phosphorus t apors therein. Fbetensive field tests, however, liave. liown no injurious effects from phosphorus smoke luider conditions which obtain in the field. 

Since organophosphorus PR s primarily work in the condensed or solid phase, development of less volatile molecules (either higher MW or reactive) will most likely reduce the risk of toxic phosphorus containing species in the smoke from burning materials such as plastics, fabrics and other combustible substrates.The effective inhibition of combustion, though, may cause an increase in the relative amount of carbon monoxide formed. But because less material is consumed, the total amount of toxicants and, therefore, the toxic hazard produced should be less than in uninhibited or poorly-inhibited combustion. 

In moist air, the phosphorus pentoxide produces phosphoric acid. This acid, depending on concentration and duration of exposure, may produce a variety of topically irritative injuries. Irritation of the eyes and irritation of the mucous membranes are the most commonly seen injuries. These complaints remit spontaneously with the soldier s removal from the exposure site. With intense exposures, a very explosive cough may occur, which renders gas mask adjustment difficult. There are no reported deaths resulting from exposure to phosphorus smokes. 

Because of the toxicity associated with the manufacture of white phosphorus and because of its field risks, a gradual shift to red phosphorus (95% phosphorus in a 5% butyl rubber base) was undertaken after World War II. The British smoke grenade (L8-Al-3), which used red phosphorus, produced adequate field concentrations of smoke and functioned as an effective tank screen. Oxidation of red phosphorus produces a variety of phosphorus acids that, on exposure to water vapor, produce polyphosphoric acids. These acids may produce mild toxic injuries to the upper airways that result in a cough and irritation. There are no reported deaths resulting from exposure to red phosphorus smokes. Therapy... 

Although some examples are known where speciflc phosphorus flame retardants increased visible smoke in small-scale tests, other instances are reported where the presence of the retardant reduced smoke. The effect appears to be a complex function of burning conditions and of other ingredients in the formulation (204,205). In one careful study, ammonium phosphate was foimd to raise or lower visible smoke from wood depending on the p5Tolysis temperatime (206). Where the phosphorus flame retardant functions by char enhancement, lower smoke levels are likely to be observed. 

A third screening smoke-type is white phosphoms [7723-14-0] (WP), P (see Phosphorus and THE phosphides), which reacts spontaneously with air and water vapor to produce a dense cloud of phosphoms pentoxide [1314-56-3]. An effective screen is obtained as the P2O5 hydrolyzes to form droplets of dilute phosphoric acid aerosol. WP produces smoke in great quantity, but it has certain disadvantages. Because WP has such a high heat of combustion, the smoke it produces from bulk-filled munitions has a tendency to rise in pillarlike mass. This behavior too often nullifies the screening effect, particularly in stiU air. Also, WP is very brittle, and the exploding munitions in which it is used break it into very small particles that bum rapidly. 

Red phosphors are formed either by heating white phosphorus or by exposing white phosphorus to sunlight. It is quite different from the explosive white phosphorus. For instance, when scratched on a surface, the heads of safety matches made of red phosphorus convert back to white phosphorus and ignite due to the heat of the shght friction of the match on a rough surface. Red phosphorus is also used in fireworks, smoke bombs, and pesticides and to make phosphoric acid, electroluminescent paints, and fertilizers. 

When phosphorus is burned with oxygen, phosphoms pentoxide (P4O10) is formed. P4O10 immediately absorbs humidity from the air to form phosphoric acid, 0P(0H)3, which gives rise to a white fog or smoke. A mixture of C2CI6, Zn, and ZnO reacts to produce zinc chloride (ZnCl2) according to ... 

Phosphine can be analyzed by GC using a NPD detector in phosphorus mode or by GC/MS. The mass ion for its identification is 34. It can be identified also from its odor and formation of smoke ring and other chemical reactions (see Reactions). 

The combustion of white phosphorus felt or red phosphorus butyl rubber will produce smoke. Smoke is an aerosol comprised of oxides of phosphorus (phosphorus pentoxide and phosphorus trioxide), some of their transformation products (see Section 3.2), and a small amount of unburnt phosphorus. The aerosol components in the smoke will undergo dispersion and chemical transformation in air to form acids or phosphorus, and will ultimately deposit from air to the hydrosphere and the lithosphere. The main components of the aerosol deposited over water and soil are acids of phosphorus. Under oxidizing conditions in soil and water, phosphorus acids will be transformed to phosphate or polyphosphates. Under reducing conditions, the disproportionation reaction of phosphorus acid can produce phosphine, and the gas may be released to the atmosphere. The fate of deposited unbumt phosphorus in water and soil has already been discussed in the preceding paragraph. 

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