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AIR POLLUTION ASPECTS
OF
PHOSPHORUS AND ITS COMPOUNDS
Prepared for the
National Air Pollution Control Administration
Consumer Protection & Environmental Health Service
Department of Health, Education, and Welfare
(Contract No. PH-22-68-25)
Compiled by Yanis C. Athanassiadis
Litton Systems, Inc.
Environmental Systems Division
7300 Pearl Street
Bethesda, Maryland 20014
September 1969
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FOREWORD
As the concern for air quality grows, so does the con-
cern over the less ubiquitous but potentially harmful contami-
nants that are in our atmosphere. Thirty such pollutants have
been identified, and available information has been summarized
in a series of reports describing their sources, distribution,
effects, and control technology for their abatement.
A total of 27 reports have been prepared covering the
30 pollutants. These reports were developed under contract
for the National Air Pollution Control Administration (NAPCA) by
Litton Systems, Inc. The complete listing is as follows:
Aeroallergens (pollens) Ethylene
Aldehydes (includes acrolein Hydrochloric Acid
and formaldehyde) Hydrogen Sulfide
Ammonia Iron and Its Compounds
Arsenic and Its Compounds Manganese and Its Compounds
Asbestos Mercury and Its Compounds
Barium and. Its Compounds Nickel and Its Compounds
Beryllium and Its Compounds Odorous Compounds
Biological Aerosols Organic Carcinogens
(microorganisms) Pesticides
Boron and Its Compounds Phosphorus and Its Compounds
Cadmium and Its Compound.s Radioactive Substances
Chlorine Gas Selenium and Its Compounds
Chromium and Its Compounds Vanadium and Its Compounds
(includes chromic acid) Zinc and Its Compounds
These reports represent current state-of-the-art
literature reviews supplemented by discussions with selected
knowledgeable individuals both within and outside the Federal
Government. They do not however presume to be a synthesis of
available information but rather a summary without an attempt
to interpret or reconcile conflicting data. The reports are
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necessarily limited in their discussion of health effects for
some pollutants to descriptions of occupational health expo-
sures and animal laboratory studies since only a few epidemio-
logic studies were available.
Initially these reports were generally intended as
internal documents within NAPCA to provide a basis for sound
decision-making on program guidance for future research
activities and to allow ranking of future activities relating
to the development of criteria and control technology docu-
ments. However, it is apparent that these reports may also
be of significant value to many others in air pollution control,
such as State or local air pollution control officials, as a
library of information on which to base informed decisions on
pollutants to be controlled in their geographic areas. Addi-
tionally, these reports may stimulate scientific investigators
to pursue research in needed areas. They also provide for the
interested citizen readily available information about a given
pollutant. Therefore, they are being given wide distribution
with the assumption that they will be used with full knowledge
of their value and limitations.
This series of reports was compiled and prepared by the
Litton personnel listed below:
Ralph J. Sullivan
Quade R. Stahl, Ph.D.
Norman L. Durocher
Yanis C. Athanassiadis
Sydney Miner
Harold Finkelstein, Ph.D.
Douglas A. Olsen, Ph0D.
James L. Haynes
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The NAPCA project officer for the contract was Ronald C.
Campbell, assisted by Dr. Emanuel Landau and Gerald Chapman.
Appreciation is expressed to the many individuals both
outside and within NAPCA who provided information and reviewed
draft copies of these reports. Appreciation is also expressed
to the NAPCA Office of Technical Information and Publications
for their support in providing a significant portion of the
technical literature.
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ABSTRACT
High concentrations of phosphorus and its compounds,
especially yellow elemental phosphorus, may cause adverse
physiological effects ranging from skin irritation to systemic
poisoning. In very low concentrations, many of the organic
and some of the inorganic compounds of phosphorus inhibit
basic metabolic processes in mammals, especially the enzymatic
activity of cholinesterases.
In vegetation, high concentrations of phosphorus in-
duce a deficiency of zinc, copper, and molybdenum, resulting
in reduced growth.
Certain phosphorus compounds—for example, phosphoric
acid—are also quite corrosive to materials.
The major sources of phosphorus air pollution are the
industries engaged in the production of phosphate fertilizers,
phosphoric acid, phosphorus pentoxide, and phosphorus chemicals
for industrial uses. The application of organophosphorus
pesticides may also result in environmental air pollution.
This is discussed in the companion report, "Air Pollution
Aspects of Pesticides . "
Recently, various organic phosphorus compounds have been
used as combustion chamber deposit modifiers as well as corro-
sion inhibitors for motor gasolines and aviation fuels. Thus
there is a possibility that automobile emissions may contain
toxic phosphorus compounds.
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Phosphorus concentrations in the ambient air of Los
Angeles (1954) and Cincinnati (1966) were found to average
1.43 |J,g/m3 , and 0.22 |ag/m3 , respectively. Measurements on
national or regional scales are not available.
No information has been found on economic costs of
phosphorus air pollution. Investment in air pollution control
equipment within the phosphate industry has been relatively
high, especially in Florida, where the phosphate fertilizer
industry is concentrated. Operating costs of control equip-
ment in this section of the fertilizer industry have been
estimated at $6 million annually; this also includes the
control of fluoride emissions.
Most of the abatement systems used in the phosphorus
industry are not specific for phosphorus, since often the
major pollutant is fluoride emissions (in the phosphate fer-
tilizer industry). Those systems which are used include
combinations of scrubbers; cyclones; mist eliminators; high-
energy, wire-mesh contactors; and electrostatic precipitators.
Methods available for quantitative analysis of
phosphorus in the atmosphere include colorimetric (molybdenum
blue method), fluorescent, and spectrophotometric methods.
Some of these methods permit determinations down to the micro-
gram level.
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CONTENTS
FOREWORD
ABSTRACT
1. INTRODUCTION 1
2. EFFECTS 3
2.1 Effects on Humans 3
2.1.1 Elemental Phosphorus 4
2.1.2 Inorganic Compounds 5
2.1.3 Organic Compounds 7
2.2 Effects on Animals 11
2.2.1 Commercial and Domestic Animals .... 11
2.2.2 Experimental Animals 12
2.2.2.1 Inorganic Compounds 12
2.2.2.2 Organic Compounds 14
2.3 Effects on Plants 15
2.4 Effects on Materials 18
2.5 Environmental Air Standards 18
3. SOURCES 20
3.1 Natural Occurrence 20
3.2 Production Sources 20
3.3 Product Sources 23
3.3.1 Phosphoric Acids 23
3.3.2 Phosphate Fertilizers 24
3.3.3 Phosphine 25
3.4 Other Sources 26
3.4.1 Oil-Fired Boilers 26
3.4.2 Iron and Steel Industry 26
3.4.3 Transportation Sources 27
3.5 Environmental Air Concentrations 28
4. ABATEMENT 30
5. ECONOMICS 32
6. METHODS OF ANALYSIS 34
6.1 Sampling Methods . . . 34
6.1.1 Free Phosphorus in Air 34
6.1.2 Phosphoric Acid (Plants, Stack Gasses) . 34
6.1.3 Phosphine 35
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CONTENTS (Continued)
6.2 Quantitative Methods 35
6.2.1 Phosphorus and Phosphoric Acid 35
6.2.2 Phosphine 37
6.2.3 Organophosphorus Pesticides 37
7. SUMMARY AND CONCLUSIONS 38
REFERENCES
APPENDIX
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LIST OF FIGURES
1. Marketed Production, Apparent Consumption, and
Exports of Phosphate Rock, 1900-66 49
2. Flow Diagram of Phosphate Rock Storage and
Grinding Facilities 50
3. Flow Diagram of Process for Production of Super-
phosphoric Acid „ . 51
40 Flow Diagram of Wet Process Phosphoric Acid
Plant 52
5. Flow Diagram of Furnace Phosphoric Acid Plant ... 53
6. Flow Diagram: Production of Run of Pile and
Granular Triple Superphosphate 54
7. Flow Diagram of Normal Superphosphate Plant . « 8 • '55
8. Cumulative Particle Size Distribution of Phosphate in
Cincinnati and Fairfax, Ohio 56
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LIST OF TABLES
1. Effects of Excessive Application of Phosphate on
Sour-Orange Seedlings 16
2. Threshold Limit Values for Phosphorus and Certain
Compounds 19
3. Emissions and Abatement Devices Used in Seven
Phosphate Fertilizer Plants 31
4. Properties/ Toxicity, and Uses of Phosphorus and Some
Phosphorus Compounds 57
5. Comparative Acute Toxicity of Cholinergic
Organophosphous Insecticides in Normal Male and Female
Rats 68
6. Comparative Toxicities of Some Phosphorus Compounds
for Experimental Animals 69
7. Production of Phosphorus Chemicals 72
8. Growth of Phosphoric Acid Industry in United States . . 73
9. Thermal-Process Phosphoric Acid Establishments in
United States 74
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1. INTRODUCTION
Phosphorus and its compounds have varying effects
depending upon the chemistry and concentration. For example,
yellow (white) phosphorus is a protoplasmic poison, while
red phosphorus is not; and some of the organic and inorganic
compounds of the element are comparatively nontoxic even at
the gram level, while some others are highly toxic in con-
centrations at the microgram level. Very few of the known
phosphorus compounds have been investigated with respect to
their toxic effects.
The adverse effects on humans and animals exposed to
concentrations of phosphorus vary from a slow, cumulative and
mostly irreversible inhibition of cholinesterase activity to
death from poisoning, depending basically on the physico-
chemical form of the elements and its concentration. The
human nervous system is the most affected by high concentra-
tions of phosphorus.
The compounds known to be emitted in appreciable
quantities into the ambient air are phosphorus oxides, phos-
phoric acid, and the organophosphorus compounds, found mostly
in agricultural chemicals. Other organic phosphorus compounds
are very probably emitted into the ambient air by the
chemical industry from processes in which phosphorus products
are intermediate and/or final outputs.
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The potential of phosphorus and its compounds as air
pollutants may possibly be increasing, since production of
phosphate rock has increased by more than 200 percent since
1950. This may pose a pollution problem in the areas where
industrial emission sources are concentrated. Also, the use
of phosphorus compounds as additives in gasoline and aviation
fuels may pose a problem.
In this report the phosphorus compounds will be
divided into two main groups for discussion—the inorganic
phosphorus compounds and the organic phosphorus compounds.
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2. EFFECTS
Elemental phosphorus (yellow) is a protoplasmic
poison. Some of its compounds, especially organic phosphates,
can also be lethal to man and animals in the case of exposure
to high air concentrations. Exposure to relatively low con-
centrations can produce serious disturbances of basic meta-
bolic processes. Acute or chronic effects from ambient air
concentrations have been studied only with respect to
organophosphorus pesticides. Such studies are few and do
not provide data on concentrations; however, they have
established that the symptoms observed are specific for and
quite similar to those found in experimental studies on the
toxicity of organophosphorus compounds.
2.1 Effects on Humans
The adverse effects of human exposure to high concen-
trations of phosphorus and its compounds vary widely both
in intensity and type, depending on the physicochemical form
of phosphorus. Some of the organic compounds of phosphorus
are known to be harmless to humans, while others have been
shown to be highly toxic. The known adverse bioeffects of
phosphates at the molecular level include inhibition of a
number of important enzymatic activities. The properties,
toxicity, and uses of phosphorus and certain of its compounds
are given in Table 4 in the Appendix.
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2.1.1 Elemental Phosphorus
There are three different types of elemental phospho-
rus: yellow (white), red, and black; each has substantially
different physicochemical and biological properties, some of
which are not yet well understood.
Elemental yellow phosphorus is an extremely toxic
substance considered to be a protoplasmic poison. Its toxic
effect is apparently due to its potent reducing properties,
which cause disturbances of intracellular oxidation pro-
47
cessess. Chronic exposure to small quantities of phospho-
rus causes epithelial damage of the bone capillaries with
47
thrombosis and bone necrosis.
The heart is one of the organs affected by phosphorus,
and several electrocardiographic anomalies have been reported
after exposure to phosphorus.12'14'15'50 In a total of 115
patients who attempted suicide with "electric paste" (rat
poison containing 2.5 percent phosphorus), 35 (30 percent)
14 15
; died, mostly from acute cardiovascular collapse. '
Red phosphorus is considered comparatively harmless;
however, inhalation of its dust has been reported to cause
i . 47
pneumonia.
Black phosphorus is an allotropic form that is synthe-
sized under high laboratory pressures and is not found under
normal conditions of temperature or pressure.
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2.1.2 Inorganic Compounds
Phosphine (PHs) is a very toxic gas which ignites
spontaneously in air. This gas produces chronic effects
similar to that observed with phosphorus.52 Acute effects
of phosphine inhalation include dyspnea, weakness, vertigo,
bronchitis, edema, convulsions, and death. The odor thresh-
old is 2 ppm (2.6 |J.g/m3 by volume).29 Phosphine acts on the
central nervous system and the blood. A concentration of
2,000 ppm (2,860,000 p.g/m3 ) is lethal to man in a few minutes.
Concentrations from 400 to 600 ppm (572,000 to 878,000
|jg/m3 ) are dangerous to life after exposures of 30 to 60
minutes. The maximum concentration tolerated for a 1-hour
exposure is in the range of 100 to 190 ppm (143,000 to 271,000
l_ig/m3 ), and the maximum that can be tolerated for several
hours without appearance of symptoms is 7 ppm (10,010 |ag/m )-27
Phosphorus trichloride (PC13) enters the body as a
vapor through the respiratory tract, causing suffocation,
bronchitis, edema, and inflammation of the lungs. The
vapors of PCla are irritating to skin, mucous membranes/
and the respiratory tract.27'31'51 Exposure to the vapors
may result in cough, painful inflammation of the eyes,
burning in nose and throat, bronchial catarrh, dyspnea, and
after severe exposure, death.23'52'62 A concentration of
600 ppm (3,600,000 |-ig/m3 ) is lethal within a few minutes.
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Concentrations of 50 to 80 ppm (300,000 to 480,000 Ug/m3)
are injurious after an exposure of 30 to 60 minutes. The
range of concentrations from 2 to 4 ppm (12,000 to 24,000
Ug/m"3 ) can be tolerated for exposures of as long as 60
minutes without serious symptoms.2^
Phosphorus pentachloride (PCls) is also poisonous,
causing adverse physiological effects similar to those
described for phosphorus trichloride.2?
Phosphorus oxychloride (POCls) is also poisonous
and causes symptoms similar to those described for phosphorus
trichloride. In the same manner, the vapors of POC13 are
irritating to skin, mucous membrances, and the respiratory
tract.26'2^ Exposure to vapors may again result in cough,
painful inflammation of the eyes, burning in nose and
throat, bronchial catarrh, dyspnea, and after severe exposure,
death.23'52'62
Zinc phosphide (Zn3?2), which is extremely toxic,
may give off phosphine and accidentally cause fatalities.
Tricalcium phosphate (Ca3(PC>4)2) is used in the
production of some dentifrices and may cause a problem
because of its low solubility (0.002 percent). Crystals of
tricalcium phosphate were found in the viscera, lymph nodes,
and enteric mucosa of a patient who died from carcinomatosis.
The presence of these crystals was explained as the result
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of excessive and careless use of a "shake-out" denture
cleaner powder. Most of the particles of this powder were
smaller than 5 u* and probably were inhaled. To test the
hypothesis that tricalcium phosphate crystals were associated
with the observed systemic lesions and cancer, experiments
were condudted with white rats63 (see Section 2.2).
Inhalation of the dust of calcium phosphate rock has
been found to affect the respiratory system adversely- Com-
parison of the ventilatory capacity of 18 men before and
after exposure to dust revealed that there was a significant
decrease in the forced expiratory volume after exposure to
the dust over several hours; greater and more consistent
decreases were observed in those men who had a history of
persistent cough accompanied by sputum.21 Phosphate rock
dust may also be emitted in significant quantities from
fertilizer manufacturing plants.
2.1.3 Organic Compounds
The effects of exposure to organic phosphorus com-
pounds through inhalation vary from acute systemic poisoning
to slow and cumulative inhibition of basic metabolic processes.
The most well-studied effect is the inhibition of cholines-
terase activity. Cholinesterase (specific, true, or acetyl-
cholinesterase) is an enzyme located in most tissues, especially
conductive tissues (brain and nerves), erythrocytes, skeletal
*ia=micron.
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8
muscles, adrenal and salivary glands, lungs, liver, and
stomach. The enzyme hydrolyzes acetycholine to acetate plus
choline, and in addition, splits other choline esters.
Organophosphorus compounds also inhibit pseudocholinesterases
(nonspecific), and some compounds are effective in extremely
low concentrations. For example, tetraethyl pyrophosphate is
an effective inhibitor at a molar concentration of 10~16, and
this effect appears to be irreversible.37
Analysis of the enzymatic action of cholinesterase has
shown that when the enzyme reacts with alkylphosphate, it be-
comes phosphorylated. The result is a phosphorylated enzyme
which, in contrast to cholinesterase, does not react with
water. Since its active side is thus blocked, it becomes
deactivated.
The inhibition of cholinesterase by alkylphosphates
may lead to accumulation of acetylcholine in synaptic junctions
and thus lead to hypersensitivity- Acetylcholine also accu-
mulates at the endings of the postganglionic cholinergic
nerves; at muscular end-plates; and in the brain. The toxicity
in man and warm-blooded animals is extraordinarily high. The
acetylcholine at the end-plates of skeletal muscles leads to
muscular weakness and possibly tonic-clonic convulsions. In
acute poisoning, cholinesterase is distinctly reduced (by more1
than 20 percent) but falls more rapidly in the plasma than in
the erythrocytes. In chronic poisoning, the determination
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of erythrocyte cholinesterase is considered a more reliable
indicator than the determination of plasma cholinesterase.
72
A follow-up study in California (1963-1964) investi-
gated the cases of 235 individuals who reportedly were occu-
pationally exposed to organic phosphates in 1960. About two-
thirds of these cases occurred in agricultural workers, and
the remaining third among workers in chemical companies, State
and local governments, nurseries, packing houses, and pest
control operations. The study was based on personal interviews
by a physician, limited physical examination, and laboratory
measurements, including determination of blood cholinester-
ase activity in two 5-ml samples of blood and in a number of
samples, measurements of serum glutamine oxaloacetic trans-
aminase, serum glutamic pyruvic transaminase, thymol turbidity,
and packed red blood cell volumes (hematocrits). The effects
of acute, systemic insecticide poisoning varied, and the
cases were divided into the following categories:
In Group 1 (87 cases), the symptoms included effects of
parasympathetic stimulation such as headache, nausea, weakness,
chest pain, vertigo, vomiting, nervousness, sweating, disturbed
vision, shortness of breath, and excessive salivation. These
symptoms were confirmed by depressed blood cholinesterase
levels.
In Group 2 (91 cases) the above described symptoms of
parasympathetic stimulation were also observed, but without
laboratory confirmation.
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10
In Group 3 (57 cases), no information on symptoms and
laboratory findings was provided. However, organic phosphate
poisoning was reported.
Of the total 235 cases originally reported, only
114 individuals stricken with acute organic phosphate
poisoning were located and interviewed. The insecticides
implicated were as follows:
Parathion 36 cases
Phosdrin 30 cases
Thimet 12 cases
Systox 5 cases
TEPP 2 cases
Trithion 2 cases
Malathion 3 cases
Phosphamidon 1 case
Combinations 23 cases
Exposure to these compounds varied. The majority of
persons studied (74.6 percent) were directly exposed through
mixing and loading of aerial sprays, ground spraying, and
work in chemical plants. Another group (22.8 percent) was
indirectly exposed as a result of picking fruits and vete-
tables, planting, irrigating, cultivating, and walking
through the fields. The remainder (2.6 percent) were exposed
by incidental contact. For the 114 cases traced, 72 blood
analyses were made, and 57 of these showed low cholinesterase
activity. Of the 114 individuals, 20 could no longer tol-
erate smelling or contact with insecticides: 12 persons
experienced nausea and/or vomiting after even a whiff of these
substances, and five others developed headache. Many indivi-
duals had avoided reexposure by shifting to other work.
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11
However, two-thirds returned to work, and 10 of these
experienced subsequent attacks of acute poisoning.
A study was made of a group of patients with chronic
trieresyl orthophosphate (C2iH21O4P) poisoning who had been
taking this organophosphorus drug orally in doses of 200 |ig.
Six of the patients showed symptoms of central and peripheral
nervous system damage in the form of a psychoorganic syndrome
accompanied by sexual and various nervous disorders. The
symptoms of mental disorders were at onset similar to those
of neurasthenia; however, the full clinical picture developed
only after 4 years. Sexual disorders consisted of an increase
in libido, which gradually developed into complete impotence.
More detailed information on the effects of organo-
phosphate compounds can be found in the companion report on
pesticides.
2.2 Effects on Animals
2.2.1 Commercial and Domestic Animals
I O
Einbrodt studied the effects on horses of mine dust
containing phosphorus pentoxide. Analysis of the lungs of
three mine horses (in Germany) showed average concentrations
of phosphorus pentoxide amounting to about 20 percent of the
total dust content of the lungs. The highest concentration
of phosphorus pentoxide was found in the bronchi (23 to 29
4.\ 18
percent).
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12
2-2.2 Experimental Animals
2-2.2.1 Inorganic Compounds
Phosphorus trichloride (PC13) hydrolyzes rather rapidly,
producing hydrogen chloride and phosphorus acid (H3PO3). When
the hydrolysis takes place in the presence of moist air, fumes
are produced.
Experiments in which 10 rats and 10 guinea pigs inhaled
dispersed PC13 vapors at concentrations of 300,000 to 600,000
Hg/m3 (total particulate) gave the following results. During
exposure, the animals were restless and nervous, and porphyrin
secretions developed around their eyes. The nostrils and paws
were swollen and edematous shortly after exposure and necrosis
was observed in the nasal epithelium and its substructure.
The major histological alterations observed consisted of
nephrosis of the kidney tubules in the corticomedullary region.
All animals died within a 10-day period after exposure. In
the case of animals exposed to ammoniated PC1_ at concentra-
. o
tions of 1,100,000 to 2,500,000 ng/m , some animals died within
3 days after exposure. All animals developed severe pulmonary
edema while the lungs of the animals which survived exposure
79
showed extensive areas of fibrosis in the alveolar walls.
The hydrolysis of phosphorus oxvchloride (POC13) occurs
rapidly in water, and quickly enough on contact with moist air
to cause fuming. The hydrolysis results in the formation of
79
hydrogen chloride (HCl) and phosphoric acid (H3PO4).
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13
Other experiments in which 10 rats and 10 guinea pigs
inhaled POC13 vapors at concentrations of 30,000 \J.g/m3 (total
particulate) gave the following results. During exposure,
the animals were restless and nervous, and porphyrin secre-
tions developed around the eyes. All deaths occurred within
48 hours after exposure. The signs of toxicity gradually
abated in surviving animals and disappeared by the end of the
14-day experimental period. The lungs of the dead animals
were dark red and showed plugs in the lumen of bronchi and
bronchioles, while the alveolar spaces around the lumen plugs
were edematous and hemorrhagic. Animals exposed to aerosols
from the dispersion of ammonia-neutralized POC1., showed the
same pattern of survival times and histological changes as
the animals exposed to pure vapors of POC13.
Tricalcium phosphate, of the type and particle size
(0.1 to 5 |~i) contained in some toothpastes, was fed to 12
white rats for periods of 3 days to 7 weeks; another 21 rats
were injected with 50,000 |_ig of a denture cleanser that con-
tained tricalcium phosphate. Examinations showed that crystals
of the phosphate had entered the intestinal mucosa of the rats
after ingestion and the lungs after injection. These crystals
were deposited in tissues and caused mild or severe inflamma-
tion and granulomas. However, the results of these experi-
ments were inconclusive with respect to a possible causal
relation between cancer and the tricalcium phosphate crystals.57
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14
2.2.2.2 Organic Compounds
The toxicity of the organic phosphorus derivatives to
mammals is directly proportional to the inhibition of acetyl-
cholinesterase produced. The phosphorus insecticides act by
deactivating (phosphorylating) the enzymes they attack. A
lowering of mammalian toxicity was achieved in recent years
by using pesticides which are toxic to insects but not to
mammals. (See companion report on Pesticides.)
The comparative toxicity of a number of organophosphorus
insecticides is given in Table 5 in the Appendix.
Experiments with mice exposed to inhalation of ethylo-
mercuric phosphate at concentrations equivalent to 0.03 to
0.04 iag/m3 of mercury was fatal to some mice after the 3rd
and 4th hour of exposure. Concentrations of ethylomercuric
phosphate above 0.04 ug/m"3 killed the mice within 1 hour,
while 0.03 to 0.04 |jg/m3 of metallic mercury failed to cause
death of the experimental animals even after 8 hours exposure.
Mice died 6 to 15 hours after exposure to ethylomercuric
phosphate vapor at concentrations equivalent to 0.006 to 0.009
|ag/m3 of mercury, while mice exposed to identical concentra-
tions of metallic mercury vapor did not die. (See companion
report on Mercury-)
Methyl phosphonic dichloride hydrolyzes rapidly
enough in the presence of moist air to produce fumes. The
products of its hydrolysis are hydrogen chloride and
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15
methyl phosphonic acid (CH3PO(OH)2),69 The vapors are
irritating to the skin, the mucous membranes, and the respira-
26,28,51
tory tract„
Experiments with rats which inhaled vapors of CH3POClo
for a 4-hour period at an average concentration of 360,000
2
Hg/m showed the following results. During exposure the
animals were restless and nervous, and the skin around the
eyes was swollen with porphyrin secretions. Breathing became
slow and difficult, necrosis was observed on paws and nostrils,
and the stomach was distended. In addition to necrotic tissues,
there were hemorrhagic edemata, areas of ulceration in the
stomach walls, hemorrhage in the pancreas and thymus, tubular
nephrosis, and excessive fat deposits in the liver, kidney,
heart, and skeletal muscles. In rats exposed to ammonia-
o
neutralized CH POC1- at a concentration of 3,600,000 i-ig/m ,
J ^
hemorrhagic edema was observed in the lungs, and death
79 ...
occurred within a day after exposure. Comparative toxici-
ties for experimental animals of certain phosphorus compounds
are presented in Table 6 in the Appendix.
2.3 Effects on Plants
Phosphorus is an essential element of plant tissues,
but excessive concentrations produce adverse effects. Most of
these types of effects result from antagonism among trace
elements. The majority of the studies have been concerned with
excessive applications of phosphates in fertilizers.
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.re
Heavy applications of phosphates can induce marked
deficiencies of trace elements—especially zinc and copper-
as shown in Table 1.
TABLE 1
EFFECTS OF EXCESSIVE APPLICATION OF PHOSPHATE ON
SOUR-ORANGE SEEDLINGS6
Phosphate
(Ib/per acre)
0
76
360
900
1,800
Shoot Weight
(qrams)
31
34
26
22
14
Leaf Composition (ppm)
Copper
5.3
4.5
2.0
1.0
1.4
Zinc
28
30
20
21
12
Phosphate-induced zinc deficiency is very common in
greenhouse crops, such as tomatoes. It has also been demon-
strated that adding phosphates to the soil where citrus
plants are grown results in decreased absorption of boron,
copper, and zinc, even though the phosphates decrease the
fi 7 TO "3^ 44
soil pH. '-LW'-'-''rrrr Moreover, the induced acute copper
deficiency is not influenced by the type of soil. In acid
soils, the uptake of zinc and boron is usually retarded,
while in alkaline soils excess phosphate decreases molybdenum
uptake. Application of heavy doses of superphosphate result
58 35 40
in a marked decrease in the zinc content of oats and flax. '
Heavy applications of phosphate in certain soils may increase
69
the molybdenum content of the vegetation as much as tenfold.
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17
In some parts of Great Britain, where the copper dificiency
in cattle is largely induced by high levels of molybdenum in
the diet, excessive concentrations of phosphates in pastures
contribute to copper deficiency by both decreasing the avail-
able copper and increasing the molybdenum content of the grass,
Even though the adverse effects of excess phosphates
are usually indirect, they are nevertheless serious enough to
be taken into account. For example, phosphate-induced zinc
deficiencies are very extensive, being found in this country
in Wisconsin, throughout the Cotton Belt, and on the Pacific
5,74,75
Coast. The extent to which industrial sources of
phosphorus air pollution contribute to the excessive concen-
tration of phosphates in soils is not known.
Two recent studies have shown that some phosphorylated
compounds—mainly sugar phosphates—inhibit carbon dioxide
2
fixation by inert spinach chloroplasts, and that addition of
phosphorus increases the severity of spinach injury produced
Q
by fumigation with ozonated hexene.
Studies of the effect of fluoride on the succinic
oxidase system in cauliflower mitochondria showed that in the
presence of phosphate, fluoride caused marked inhibition of
the succinic 2,6-dichlorophenolindophenol reductase. It is
believed that this inhibition results from the formation of
an enzyme-fluorophosphate complex- An oxidative phosphoryla-
tion were inhibited. It has also been shown that concentra-
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18
tions of phosphate in plant tissue of 0.001 |ag and greater
definitely inhibit the acitivity of succinic dehydrogenase,
and that inhibition increases with higher concentrations.
2.4 Effects on Materials
Very limited information has been found regarding
adverse effects of ambient air concentrations of phosphorus
and its compounds on materials. It is known that phosphorus
pentabromide, pentachloride, and pentoxide, are corrosive, as
38
well as phosphorus tribromide. Phosphoric acid (in solution)
is very corrosive to ordinary ferrous metals and alloys,
n 54
particularly at temperatures above 85 C. Wet phosphoric
acid is much more corrosive to metals than is phosphoric
acid made from elemental phosphorus because of the impurities
(including fluoride) contained in the wet-process acid.
2.5 Environmental Air Standards
The threshold limit values adopted and recommended in
1967 by the American Conference of Governmental Industrial
Hygienists for phosphorus and some of its compounds are shown
in Table 2.
The hygienic norms established in U.S.S.R. for ground-
level concentrations in the ambient air of phosphorus
pentoxide are as follows:
Single maximum concentration: 150 t-ig/m
Average 24-hour concentration: 50 |~ig/m
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19
TABLE 2
THRESHOLD LIMIT VALUES FOR PHOSPHORUS
AND CERTAIN COMPOUNDS60
Substance
Threshold Limit Value
(PPm)
Phosdrin (Mevinphos)—skin*
Phosphine
Phosphoric acid
Phosphorus (yellow)
Phosphorus pentachloride
Phosphorus pentasulfide
Phosphorus trichloride
0.3
0.5
100
400
1,000
100
1,000
1,000
3,000
*Potential contribution to the overall exposure by
the cutaneous route, including mucous membranes and eye,
either by airborne or direct contact with the substance.
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20
SOURCES
3 .1 Natural Occurrence
Natural phosphates are divided into three classes on
the basis of the metal or metals to which the phosphorus is
bound. The three major classes are aluminum (iron) phosphates,
calcium-aluminum (iron) phosphates, and calcium phosphates.
The last class is the most important one for the phosphate
fertilizer industry; its principal members are bone and apatite
found in phosphate rock. Since the discovery in 1867 of de-
posits in South Carolina, phosphate rock has become increasingly
important and is now practically the only source of Phosphorus.
The average concentrations of phosphorus pentoxide (P_O5) were
estimated (1961) as 33.4 percent in phosphate rock from the
mines of Florida (land pebbles), 32.0 percent in that from
Tennessee, and 31.2 percent in phosphate rock from the
Western States. The major constituents of phosphate rock are
P2O5 (27.5 to 33.0 percent); calcium oxide (41.9 to 46.1 per-
cent); volatile matter (1.9 to 7.0 percent); fluorine (2.9 to
4.4 percent); carbon dioxide; and oxides of silica, iron,
aluminum, sulfur, potassium, and magnesium.
3.2 Production Sources '
The major portion of all phosphorus produced comes from
phosphate rock. Domestic marketable production of phosphate
rock displays a very fast rate of growth, as shown in Table 7
and Figure 1, Appendix. Starting with less than 2 million
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21
long tons in 1900, marketable production reached 4 million
tons in 1940, 10 million tons in 1950, approached 20 million
tons in 1960, and reached 35 million tons in 1966. A total
of 100 million long tons of rock with a phosphorus pentoxide
^P2°5^ cont-ent of 16.43 percent was mined in 1966.
In 1965, about 73 percent of the total domestic output
was produced in Florida, 10 percent in Tennessee, and most of
the remaining 17 percent in Idaho, Montana, Arkansas, Utah,
and Wyoming, in the order listed. Florida's phosphate rock
contains from 20 to 35 percent phosphorus pentoxide.
Most phosphate rock is used for the production of
fertilizers. The distribution of phosphate rock sold or used
by producers during the period 1965-1967 was as follows:
Percent
19654q: 1966^ 19674b
Phosphoric acid (wet process) 21.0 28.5 41.0
Triple superphosphate 21.5 27.6 16.0
Electric furnace phosphorus 29.0 23.7 21.5
Oridnary superphosphate 25.0 17.9 18.3
Other (mostly for agriculture) 3.5 2.3 3.2
Emission sources of particulates in storing and grinding
phosphate rock are shown in Figure 2 in the Appendix.
Crude phosphates and phosphate fertilizers imported into
the United States represent less than 1 percent of the total
domestic consumption. Thus in 1966, the imports of crude
phosphates amounted to 178 short tons or about 0.7 percent of
the domestic apparent consumption, while imports of phosphate
fertilizers and fertilizer materials amounted to 268 short
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22
tons. Most of the small amounts of phosphate rock imported
is used as animal feed supplement because of the rock's low
fluorine content.45
Elemental phosphorus is produced as a final product
for the chemical industry and as an intermediate product in
the production of phosphoric acid and fertilizers.
Analysis of the flue dust samples obtained from the
phosphorus furnace operations of the Monsanto Chemical Company
(Monsanto, Tenn. ) showed that phosphorus pentoxide (P2C>5) as
particulate constituted 18.89 percent of the flue dust. Data
on gases evolved from the flue dust during heating showed
that phosphine and phosphorus pentoxide fumes (collected in
water) amount to 0.09 and 0.67 percent by weight of the total
78
charge. Flue dust is carried by the furnace gases along with
the vaporized elemental phophorus and is collected, while
hot, by an electrostatic precipitator before the gases reach
the phosphorus condenser.
It should be noted that during the industrial produc-
tion of phosphorus, it is possible that particles of elemental
phosphorus may be emitted. Free phosphorus can exist in air
as a vapor because there are upper and lower limits on the
ratios in which oxygen and phosphorus react. Consequently,
it cannot be assumed that all of the free phosphorus reacts
f\ "7
to form phosphorus oxides and suboxides.
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23
3.3 Product Sources
3.3.1 Phosphoric Acids
The types of phosphoric acids produced are ortho- and
superphosphoric acids. In the production of orthophosphoric
acid, the primary pollutant is phosphoric acid mist. Emission
of P2°5 is ^n the range of °-3 to 5-° pounds per thousand
2
pounds of elemental phosphorus (P4) burned. Superphosphoric
acid (containing more than 70 percent P2°5^ i-s made bY
dehydrating wet-process acid or by burning elemental phosphorus
with air as in the furnace process, except that in the hydrator,
the cooling of the combustion gas is done with water or diluted
acid sprays. About half of the P2C>5 drops out of the vessel
as superphosphoric acid, while the rest leaves as acid mist
at 200° F and is collected as less concentrated acid in an
electrostatic precipitator. The diluted acid is sprayed back
into the hydrator, and the effluent gas from the precipitator
is vented to the stack. Superphosphoric acid is also made
from the normal 50 to 55 percent acid. The primary pollutant
is the phosphoric acid mist that is not removed by the mist
eliminator. The quantity of acid mist can be assumed to be
about equal to or less than that vented in the furnace process
and is related to the efficiency of the precipitator. Pro-
ducing phosphoric acid from the wet-process acid is carried
out in a high vacuum, which tends to limit emissions. More
information can be found in reference 21. In 1967 there were
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24
about 44 plants using the wet process and new plants are
being built.2'68'71
Flow diagrams of processes used for the manufacture of
superphosphoric, wet-process phosphoric, and furnace phosphoric
acids are shown in Figures 3, 4, and 5 in the Appendix.
Phosphoric acid ranked second in production value
(after ammonia) among the top 73 inorganic chemicals pro-
duced in 1965 and ninth in terms of production amount.9
Table 8 in the Appendix shows the growth of the phosphoric
acid industry in the United States.2
The location of thermal process phosphoric acid
plants in the United States is given in Table 9 in the
Appendix.
Phosphoric acids are used for the production of ferti-
lizers, animal feed supplements (mono- and dibasic calcium
phosphates), and detergents (sodium and potassium polyphos-
phates).
3.3.2 Phosphate Fertilizers
Phosphate fertilizers are produced from phosphoric
acid and phosphate rocks.
The major types of phosphate fertilizers are:
Diammonium phosphate
Triple superphosphate
Normal superphosphate
Monoammonium phosphate
Ammonium phosphate sulfate
Ammonium phosphate nitrate
Ammonium polyphosphates (solid and liquid)
Nitric phosphates
Other mixed fertilizers
Phosphoric acid applied directly to soil
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25
In the above list, the first three fertilizers are the most
important in the order shown. Diammonium phosphate production
(48 percent P2°5) has been replacing or reducing production
of triple superphosphate. In 1965 there were about 48 plants
producing Diammonium phosphate.68 Emission points are shown
in Figure 6 in the Appendix.
Triple superphosphate is produced in large plants near
phosphate rock deposits. In 1965, there were 16 plants in
the United States producing 5.3 million tons per year.68
Normal (ordinary) superphosphate fertilizers are pro-
duced by reacting sulfuric acid with phosphate rock. In
1965 there were over 200 plants involved in this process, but
production is declining as more concentrated ^2^5 Pr°ducts
(triple superphosphate) are being produced. The gases
released from acidulation of phosphate rock are the major
emissions. Emission points are shown in Figure 7 in the
Appendix.
3.3.3 Phosphine
Phosphine is an industrial hazard in (l) the manufac-
ture of acetyleine, where calcium phosphide is an impurity
in the calcium carbide used in the process, (2) phosphorus
extraction, (3) manufacturing of phosphorus sesquisulfide,
and (4) industrial operations with phosphorus-bearing ferro-
silicon. Phosphine may, under low pH conditions, be evolved
from ferrophosphorus in the production of elemental phosphorus
-------
26
by the electric furnace process. Phosphine is also generated
during the acid pickling of steel which contains small amounts
of iron phosphide.
3.4 Other Sources
3.4.1 Oil-Fired Boilers
The fuel oil used most in boilers that produce steam
at a rate of 1,000 hp/hr (approximately 34,500 Ib/hr) or more
is designated as Bunker C, residual, high viscosity, heavy,
grade 6, or Pacific Standard 400. Elemental analyses of
total particulates in the fly ash from the combustion of
residual oil showed in one test that phosphorus (as phosphorus
pentoxide) amounted to 0.9 percent of the total solids collected
in a laboratory electrical precipitator at 230° F.6^ In small
emission sources (less than 1,000 hp/hr), the fly ash loadings
f\ ^
are higher than for large sources. 3
The concentration of total phosphorus in the fly ash
from residual-oil-fired boilers has not been measured, nor
has the variation in phosphorus emission rates with respect
to the variation in other operating parameters been determined.
3.4.2 Iron and Steel Industry
64
Schueneman et al. reported that phosphorus pentoxide
accounted for an average of 0.2 percent of the total weight of
fume produced during an entire melting cycle in an electric-
arc steel furnace. In a 15-ton-arc steel furnace in which
dust collection of about 7 Ib/ton of melted steel was obtained,
-------
27
a typical analysis made in 1959 showed that the dust contained
0.4 percent phosphorus (as phosphorus pentoxide).16
A typical analysis of the precipitator dust collected
during high-purity oxygen injection from an open-hearth steel
furnace (U.S. Steel Corporation, Allegheny County, Pa.) showed
a phosphorus pentoxide content of 1.18 percent,63 while in
basic oxygen furnaces, chemical analysis showed that phosphorus
pentoxide amounted to 0.3 percent of the dust and fume.
In a recent analysis of oxygen-lanced open-hearth
furnace fume, phosphorus pentoxide amounted to 0.5 percent.
In a study-* of the efficiency of mineral wool filters
in collecting acid mists from open-hearth furnaces and other
steel producing operations, the concentration of phosphoric
acid mist was found to range from 45,000 to 110,000 |jg/m3 .
3.4.3 Transportation Sources
Many organophosphorus derivatives have been widely
used to reduce corrosion resulting from the combustion of
gasolines and aviation fuels. Approved inhibitors for avia-
tion fuels include alkylamiphosphate and 25 percent octyl
phosphate esters, and 25 percent octyl phosphate and 50 per-
cent ammonium alkyl phosphates for gasoline. Ammonium alkyl
phosphate is also used an an anti-icing agent. Concentrations
of these additives range from 5 to 20 pounds per 1,000 barrels
(2.3 to 9 grams per barrel) of aviation fuel.
Phosphorus-containing additives (organophosphorus com-
pounds) are also used as modifiers of combustion chamber
-------
28
deposits resulting from surface ignition in motor gasolines,
as well as inhibitors of spark-plug fouling. The list of
such phosphorus compounds commercially available for use in
gasoline includes tri-isopropyl phosphite, tri-cresyl phos-
phate, tri-chloropropyl thionophosphate, dimethyl xylyl
phosphate, dimethyl phenyl phosphate, trimethyl phosphate,
mixed cresyl phenyl phosphate, and alkyl aryl phosphate.
It is possible that part of the phosphorus in fuel
additives is emitted into the ambient air as part of the
exhaust gases, and an investigation into this matter appears
to be desirable.
3.5 Environmental Air Concentrations
The National Air Sampling Network has not been measuring
concentrations of phosphorus and its compounds in the ambient
air, and very limited data are available.
Measurements of aerosol and vapor phase phosphates in
the Los Angeles atmosphere (1954) indicated that concentration
values range from less than detectable limits to 4.23 i-ig/m3
(the average being 1.43 ng/m3).
q o
Measurements were made during the period February 14
to April 21, 1966 of air samples from Cincinnati and Fairfax
(a suburb of Cincinnati). Single cascade impactors operated
for 24-hour periods were used to collect particulates for
colorimetric analysis, and both organic and inorganic phos-
phates in the form of orthophosphate were found. The average
phosphate concentrations were 0.22 |_ig/m in Cincinnati and
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29
0.31 p.g/m3 in Fairfax; the corresponding median particle dia-
meters were 2.7 and 3.9 ^ respectively. The average particle-
size distribution curves for phosphates in Cincinnati and
Fairfax are shown in Figure 8 in the Appendix. It can be
seen that while the median diameter is in the micron range,
about 20 percent of the total mass is in the submicron range.
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4. ABATEMENT
In the production of phosphoric acid by the thermal
process, the major pollutant is phosphoric acid mist. There
are several pollution control devices used which are discussed
below; one of the most important factors influencing emission
rates is maintenance of the collection equipment.
Scrubbers. The use of packed and open tower scrubbers
is a simple and low-cost abatement technique. Collection
efficiencies vary from 40 to 95 percent for gas velocities
of 2 to 7 ft/sec. Improved efficiency has been achieved by
installing wire-mesh mist eliminators after the scrubber.
Venturi scrubbers are also used and have higher collection
efficiency, ranging from 78 to 98 percent for particle sizes
of from 0.5 to 1 [a, respectively.
Cyclones. Cyclones have comparatively low collection
efficiencies since they are effective only in the particle-
size range of 10 |~i and above. In some plants they are
compelemented with wire-mesh mist eliminators or used in
series with venturi scrubbers. In this case a collection
efficiency of up to 99.9 percent of the acid mist can be
achieved.
Fiber Mist Eliminators. Plants using glass-fiber mist
eliminators operating with gas velocities ranging from 0.4 to
13 ft/sec provide collection efficiencies of 96 to 99.9 percent.
High-Energy Wire-Mesh Contactors. High-energy wire-
mesh contactors can operate at high vapor velocities of 20 to
-------
31
30 ft/sec and provide collection efficiencies that exceed
99.9 percent.70
jElectrostatic Precipitators. Electrostatic precipita-
tors show high collection efficiencies of 98 to 99 percent,
but also high maintenance costs. The factors affecting their
performance are the rate of gas flow or temperature and the
electrical conditions during their operation.
24
In a study made by the International Minerals and
Chemicals Corporation, it was found that the optimum type of
equipment (in the farm chemicals industry) for the control of
phosphorus pentoxide (P2C>5) losses in the fumes is a modified
single-stage venturi scrubber followed by an impingement
basin. The data reported on emissions from seven plants,
together with abatement devices used, are shown in Table 3.
TABLE 3
EMISSIONS AND ABATEMENT DEVICES USED
IN SEVEN PHOSPHATE FERTILIZER PLANTS24
Grade manufacturing: 5-10-10 to
10-20-10 production rate, tons/hr
Emission rates
Solids, Ib/hr
Fume , Ib/hr
Number of Cyclones*
Average
21
36
110
3
Range
15-32
13-138
31-241
2-4
*Scrubbers used in five out of the seven plants in
conjunction with cyclones.
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32
5. ECONOMICS
In the production of phosphoric acid by the thermal
process, capital cost of wire-mesh mist eliminators (a recent
and effective abatement device) is reported to be approxi-
mately $1.50/ft3/min of stack gas.11 Except for electrostatic
precipitators, maintenance costs of collection equipment are
not high. When a continuous emission monitor is used, ex-
cessive emissions can be easily detected. Since the pollutant
is also the final output (product) of the process, attempts
2
are usually made to minimize losses from the collection system.
In the farm chemicals industry (phosphate fertilizers,
insecticides, etc.) investment in pollution abatement equip-
ment during the last few years have been quite large. Most
of this equipment is also used to reduce emissions of other
pollutants, such as fluorine and ammonia. For example, Agrico
Chemical Company has added a large exhaust and scrubber system
costing $581,000 to the control equipment at its phosphate
complex in Pierce, Fla., and about $400,000 worth of scrubber
systems at several of its phosphate fertilizer plants in
other areas. Other companies have been spending comparable
24
amounts for installation of abatement equipment.
There have been large investments in the field of
research and development as well as in monitoring systems.
According to statistics by the Florida Phosphate Council, the
phosphate companies operating in the Polk-East Hillsborough
area have spent $48 million to date in research, development,
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33
and installation of air pollution control systems for all air
pollutants. Cost of operation and maintenance has been esti-
mated at more than $6 million annually. Cost of installed
air pollution equipment varies from 20£ to $3.50 per cubic
foot per minute (cfm).
A study24 made by the International Minerals and
Chemicals Corporation showed that phosphorus pentoxide (P2°5)
losses varied from 3 to 53 Ib/hr. The value of these losses
—including those of nitrogen and potassium—varies from $3.63
to $10.66/hr.
55
It has been estimated that by 1980, the U.S. electric
utility industry alone will produce some 45 million tons of
fly ash per year, containing 400,000 tons of phosphorus
pentoxide. Utilized fly ash represents only 6 percent of the
current annual production, while the rest is dumped.
Disposal for this type of waste costs about $2 per ton and
creates a nuisance as well.
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34
METHODS OF ANALYSIS
6.1 Sampling Methods
6.1.1 Free Phosphorus in Air
One of the problems in phosphorus determination is
separating free phosphorus from the many phosphorus compounds
found in the urban air. A recently developed sampling method
draws air through a macro impinger containing 100 ml of
xylene at a rate of 1 cfm for 15 minutes. A filter paper
attached to the exit catches any fumes which pass through the
, 60
xylene.
6.1.2 Phosphoric Acid (Plants, Stack Gases)
Sampling of phosphoric acid mist in gas effluents from
stacks of phosphoric acid plants (thermal process) can be
done by a method based on that used by the U.S. Public Health
Service for particulate sampling. The sampling train consists
of a probe, cyclone, filter, four impingers, pump, dry-gas
2
meter, calibrated orifice, and manometer, in the order listed.
The cyclone is designed so that particulate samples can be
separated into two fractions, one having particle diameters
less and the other having particles greater than 5 M.. The
first two impingers contain water, the third one is dry, and
the fourth contains silica gel. When phosphoric acid mist is
sampled/ the fritted-glass and paper filters are removed, so
that all particles passing through the cyclone are collected in
the imp in ge r s.
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35
6.1.3 Phosphine
In a spectrographic method developed recently for the
rapid determination of phosphine, air samples are collected
at the rate of 0.5 liter per minute (for about 10 minutes) in
a fritted-glass bubbler. The bubbler has a collection effi-
ciency of 86,2 percent at 0.5 liter per minute (75 percent at
1 liter per minute) and contains silver diethyldiocarbamate.
6.2 Quantitative Methods
6.2.1 Phosphorus and Phosphoric Acid
Phosphorus is usually determined and estimated as
phosphoric acid expressed as phosphorus pentoxide (^2°5^ '
This determination may be done gravimetrically by forming a
magnesium pyrophosphate (Mg^P-Oy ) precipitate, titrimetrically,
£» £
27
or colorimetrically .
32
A number of colorimetric methods are available, most
of which are based on the development of a blue color when
molybdate is treated with a reducing agent. The ring-oven
colorimetric method66 uses as a reagent orthodianisidine molybdate
dissolved in glacial acetic acid which contains sodium molybdate.
The limit of identification is 0.002 tag and the range 0.05 to
2.0 |jg.
The interference of phosphate in fluorimetric procedures
became the basis of various studies aimed at developing a
highly sensitive method of determining trace amounts of phos-
phate.32 One such method, based upon fluorescence quenching
-------
36
by phosphate of aluminium-morin chelate, permits the deter-
mination of 0.5 to 10 Lig of phosphate, or 0.5 to 0.1 |j.g/ml
in solution. Ions of a number of elements, especially metals,
were found to interfere; and for the method to be specific,
phosphate is separated from such ions.32
Recently, a method has been developed for the deter-
mination of free phosphorus and phosphorus vapor in air that
depends on trapping the element and its compounds in xylene.
Separation of phosphorus compounds from free phosphorus is
done by dissolving the compounds in water and separating the
phases, converting the free phosphorus to silver phosphide,
oxidizing the phosphide to phosphate, and estimating the phos-
phate by the molybdenum blue method. Standards are prepared
in the range of 0 to 35 |ag of phosphorus, and the colorimetric
60
portion of the procedure is carried out with each standard.
Determination of phosphorus in phosphoric acid emitted
from stacks of phosphoric acid plants can be made with the
ammonium phosphomolybdate colorimetric method, which is based
on the spectrophotometric determination of the yellow
ammonium phosphomolybdovanadate complex formed when ortho-
phosphate reacts with the reagent in an acid medium. The
method is applicable to materials in which phosphorus com-
pounds can be quantitatively oxidized to the orthophosphate
9 9 59 73
form. ' Interference comes from (1) certain ions which
reduce the color to molybdenum blue, (2) oxalates, tatrates,
-------
37
and citrates which tend to bleach the color, (3) high concen-
trations of iron and (4) of dichromate, resulting from the
close resemblance of the color of the dichromate ion to the
yellow complex ammonium phosphomolybdovanadate. This method
is applicable to the determination of total phosphates in the
concentration range of about 50 |_ig to 2,000 |Jg, with a repli-
cation precision of - 1.0 percent. Another method used
for the determination of phosphoric acid in stack gas samples
is acid-base titration.
6.2.2 Phosphine
Phosphine in air can be determined by colorimetric
13
methods. Recently a spectrographic method has been developed
for the rapid determination of phosphine in the range of 0.1
to 1 ppm. The method uses silver diethyldiocarbamate as
reagent and depends on the formation of a complex of phos-
phine and the reagent with an absorption maximum at 465 m|a.
It is necessary to calibrate the procedure by a second method
analyzing phosphine as phosphate, since no primary phosphine
standards are presently available.
6.2.3 Organophosphorus Pesticides
For the detection of organophosphorus pesticides, gas
chromatography has been used in conjunction with a flame-
39 25
photometric, thermionic, or electron-capture detector. See
companion report on pesticides for more details on analytical
methods of organophosphorus pesticides.
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38
7. SUMMARY AND CONCLUSIONS
Some forms of phosphorus are toxic to humans and
animals. Yellow phosphorus is a protoplasmic poison, while
red phosphorus is comparitively nontoxic. Some of the phos-
phorus inorganic compounds, such as phosphine gas, are highly
toxic at concentrations of 400 to 600 ppm, while others—such
as tricalcium phosphate—are only mildly so. Many of the
organic compounds of phosphorus are extremely toxic. However,
very few of the known phosphorus compounds have been investi-
gated with respect to their toxic effects on humans, animals,
and plants.
The effect of some phosphorus compounds is the inhibi-
tion of cholinesterase, a process which is slow and sometimes
cumulative and irreversible. The nervous system is affected
by this type of adverse action. Nevertheless, the potential
hazard represented by the ambient air concentrations of phos-
phorus and its compounds is unknown.
The source of almost all phosphorus and phosphorus
products is phosphate rock. The major uses of phosphorus com-
pounds are the manufacturing of fertilizers, pesticides, and
industrial chemicals. These processes are the major sources
of phosphorus emissions in the ambient air. Boilers and
furnaces burning some crude oils and coals which contain phos-
phorus represent secondary emission sources of phosphorus com-
pounds. The production of phosphorus and its primary products
-------
39
has been increasing annually. Production of phosphate rock
in 1966 was more than three times the 1950 level (approximately
100 million long tons), while the production of phosphoric acid
shows the highest rate of increase among major industrial acids.
No national data exist on the ambient air concentrations
of phosphorus. The few local data available from special
studies indicate an average ambient air concentration, in
1954, of 1.43 Lig/m3.
Abatement of phosphorus emissions includes the use of
scrubbers, fiber mist eliminators, high-energy wire-mesh con-
tactors, and electrostatic precipitators.
No information has been found on economic costs of
phosphorus air pollution. Investment in air pollution control
equipment within the phosphate industry has been relatively
high, especially in Florida, where the phosphate fertilizer
industry is concentrated. Operating costs of control equip-
ment in this section of the fertilizer industry have been
estimated at $6 million annually; this also includes the
control of fluoride emissions.
The quantitative determination of phosphorus and its
compounds in the environmental air is made by colorimetric
and spectrographic mathods. The most frequently used is the
molybdenum blue method (colorimetric). Specific methods have
been or are being developed for the determination of elemental
phosphorus, phosphoric acid, phosphine, and organophosphorus
-------
pesticides. Maximum sensitivities are in the microgram level
or below.
Based on the material presented in this report, further
studies are suggested in the following areas:
(1) Determination of the long-term exposure effects
on man, animals, and plants of phosphorus and its inorganic
and organic compounds.
(2) Determination of the concentration of phosphorus
in the ambient air, by type of compounds wherever feasible,
in the stations monitored by the National Air Sampling Network.
(3) Evaluation of the pollution contribution by
phosphorus from selected stationary emission sources,
particularly significant local sources, such as the fertilizer
industry.
(4) Evaluation of the pollution contribution by
phosphorus compounds emitted from transportation sources.
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41
REFERENCES
1. Aldridge, W. N., and J. M. Barnes, Some Problems in
Assessing the Toxicity of the "Organophosphorus" Insecti-
cides Towards Mammals, Nature 169:345 (1952).
2. Atmospheric Emissions from Thermal-Process Phosphoric
Acid Manufacture, U.S. Dept. of Health, Education, and
Welfare, Public Health Service, U.S. Govt. Printing
Office, Washington, B.C. (Oct. 1968).
3. Bamberger, E. S. , et ail. , Effect of Phosphorylated Com-
pounds and Inhibitors on CO2 Fixation by Intact Spinach
Chloroplasts, Plant Physiol. 40(5):919 (1965).
4. Bear, F. E., Trace Elements—Progress Report on Research,
Aqri. and Food Chem. _2_:244 (1954).
5. Billings, C. E. , _et ai_. , Simultaneous Removal of Acid
Gases, Mists, and Fumes with Mineral Wool Filters, .J.
Air Pollution Control Assoc. 8.(3):185 (1958).
6. Bingham, F. T. , et_ al_. , Effect of Phosphorus Fertiliza-
tion of California Soils on Minor Element Nutrition of
Citrus, Soil Sci. J36.:24 (1958).
7. Bingham, F. T., et al., Solubility and Availability of
Micronutrients in Relation to Phosphorus Fertilization,
Soil Sci. Soc. Amer. Proc. 24.:209 (1960).
8. Brewer, R. F. , _et_ aJL.. , Influence of N-P-K Fertilization
on Incidence and Severity of Oxidant Injury to Mangels
and Spinach, Soil Sci. 92.(5)-.298 (1961).
9. Chemical Origins and Markets, Stanford Research Institute,
Menlo Park, Calif„ (1967).
10. Chester, C. G. C. , et .al.. , The Role of Zinc in Plant Meta-
bolism, Biol. Rev. 26,1239 (1951).
11. Collector 99.9% Efficient: Pressure Drop Moderate, Chem.
Processing (Chicago), p. 48 (1966).
12. Dathe, R. A., _et al., Electrocardiographic Changes
Resulting from Phosphorus Poisoning, Am0 Heart J. 31:98
(1946).
13. Dechant, R. , et a.1. , Determination of Phosphine in Air,
Am. Ind. Hyg. Assoc. J. .27:75 (1966).
14. Diaz-Rivera, R. S. , et aj... , Acute Phosphorus Poisoning
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-------
42
15. Diaz-Rivera, R. S., et al., The Electrocardiographic
Changes in Acute Phosphorus Poisoning in Man, Am. J.
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17. DuBois, K. P., _et .al. , Influence of Induction of Hepatic
Microsomal Enzymes by Phenobarbital on Toxicity of Organic
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18. Einbrodt, H. J. , est. al,. , Die chemische Zusammensetzung
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20. Fedor, W. S. , Inorganics Steady in a Slowdown, Chem. Enq.
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21. Gandevia, B. , _e_t .§_!„ , Relevance of Respiratory Symptoms
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22. Guinland, K. P., &t jJ., Spectrophotometric Determination
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25. Ives, N. F., et.. al.. , Pesticide Residues, Investigation
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27. Jacobs, M. B., The Analytical Toxicology of Industrial
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-------
43
28. Jacobson, K. H., The Acute Toxicities of Some Intermediates
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29. Kloos, E. J., Gas Masks for Respiratory Protection Against
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Wiley, 1950).
32. Land, D. B., _et aJL.. , A Fluoremetric Method for Determining
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40. Millikan, C. R., Effects of Phosphates on the Development
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41. Minerals Yearbook, Bureau of Mines, U.S. Govt. Printing
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-------
44
43• Minerals Yearbook. Bureau of Mines, U.S. Govt. Printing
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-------
45
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-------
46
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-------
47
OTHER REFERENCES
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Containing Compounds in Biological Materials. II. Acid-
Soluble Nucleotides, Short Communications, Anal. Biochem. 2.
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Wett, T. W. (Ed.), Competitors Collaborate to Choke Off Air
Pollution, Chem. Processing 31(1):27 (1968).
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Fla.) 77:516 (1964).
-------
APPENDIX
-------
49
Long Tons
X 106
' (2)
/ Consumption
1900
1910
1920
1930
1940
1950
c
1960 1965
1980
(1) Marketed production (sold or used)
(2) Apparent consumption (=production + imports-exports)
FIGURE 1
Marketed Production, Apparent Consumption, and
Exports of Phosphate Rock, igoO-GG^1"45-71
-------
Wet
Phosphate
Rock
Exit (Particulate SO2]
Dryer
Storage Silo
Exit (Particulate)
Grinding Mill
Phosphate Rock
Dust Silo
Exit (Particulate)
Storage Bins
Fuel Natural Gas or Fuel Oil
FIGURE 2
Flow Diagram of Phosphate Rock Storage and Grinding Facilities
68
Ul
o
-------
Liquid Phosphorus
St63rn
^
Phosphorus Tank
Cooling
Water
Water
->
CD
-O
C
o
u
u
CO
C
P205
Acid Mist Vent 'Gas
o
CO
•O
Dilute Acid
<-
Water
Recycle Superacid
76% P2O5
-^
Exjt^
•Exhaust Gases, Acid Mist
Precipitator
Agitated
Cooling Tank
A
CD
V
Storage
en
FIGURE 3
Flow Diagram of Process for Production of Superphosphoric Acid
68
-------
Sulfuric Acid
W
Reactor
Phosphate Rock
Exit
Si F- and HF to Wet Scrubber
A
Weak Acid
Recycle
Filter
V
-^
A
30-32% P^05
Acid Storage
Gypsum to Waste
Water
Exit to
Condenser
A
Vacuum Source
(Fluorides)
Hj2SiF6 to Recovery
or Waste
->
Vacuum
Evaporator
v
Product
54% RO Acid
2 o
FIGURE 4
Flow Diagram of Wet Process Phosphoric Acid Plant
68
ui
-------
Dilute Phosphoric Acid
Water
Phosphorus
Air
Combustion
Chamber
V
Hydration
Tower
Absorber
Tower
o
TO
>
i-
CD
NaHS
Treating
Raw Acid
To Spray Chamber
Demister or Venturi
Collector
HS
To Storage
Food Grade
phosphoric Acid
FIGURE 5
Flow Diagram of Furnace Phosphoric Acid Plant
68
u-
u;
-------
Exit
(Fluoride)
Exit
(Ammonia, Fluoride & Particulate)
Phosphoric Acid
Phosphate Rock
•^
\
f
Mixer
/
\
/
\
"^^
Belt Den
X
s
/\ '
Exit
(Fluoride) (Particulate and Fluoride)
/
\ A
NH
3
V
Granulated
Curing
S
Product
/ Run of Pile Product
Exit
Exit (Fluoride)^
Phosphoric Acid ^
Phosphate Roc
s
\
t
Mixer
/
k
\
1
\
•^
Blunger
N
/
Dr
(Particulate, Fluoride & Sulfur Oxide) ^
Exit (Particulate)
A >
Granulated Product
vpr . T Sprr*pn _ ^
FIGURE 6
Flow Diagram: Production of Run of Pi
and Granular Triple Superphosphate
-------
Gaseous Fluoride Particulate and
Sulfur Dioxide
Exit (Gaseous Fluoride)
(Ammonia Particulate) Exit
(Ammonia Particulate)
Exit (Gaseous Fluoride)
Ammoniator
Granulator
Run of Pile Product
Grinding
(Particulate) Exit
Bagging Product
•a
CD
D
C
2
i O
FIGURE 7
Flow Diagram of Normal Superphosphate Plant"
68
Ul
Ul
-------
56
o
u
1
6.0
5.0
4.0
3.0
2.0
U
t
fO
Q-
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2 -
0.1
Fairfax
o-
Cincinnati
J L
_L
J L
0.01 0.05 0.2 0.5 1 2 5 10
% Mass ^ Diameter
20 30 40 50
FIGURE 8
Cumulative Particle Size Distribution of
Phosphate in Cincinnati and Fairfax,
-------
TABLE 4
PROPERTIES, TOXICITY, AND USES OF PHOSPHORUS AND SOME PHOSPHORUS COMPOUNDS38
Compound
Phosphorus
P
Pho sphamidon
C10H19C1N05P
Properties
White phospho-
rus: colorless
or yellowish
cry-s trail ine
solid
mp 44.1°
bp 280°
volatile
Black phospho-
rus: crystals
Red phosplio-
rus t red to
violet powder
Sublimes at
416°
Oil
bp 162°
Toxic itv
White phosphorus: inges-
tion of even small amounts
may produce severe gastro-
intestinal irritation,
bloody diarrhea, liver
damage, skin eruptions,
oliguria, circulatory
collapse, coma, convul-
sions, death. The approx-
imate fatal dose of
white (also called yellow)
phosphorus is 50 mg. Ex-
ternal contact may cause
severe burns. Chronic
poisoning (from ingestion
or inhalation) produces
spontaneous fractures,
anemia, weight loss
Red phosphorus is rela-
tively nontoxic unless it
contains the white form as
an impurity
Cholinesterase inhibitor
Uses
Red phosphorus: in pyro-
technics, manufacture of
safety matches, organic syn-
thesis; in manufacture of
phosphoric acid, phosphine
phosphoric anhydride, phos-
phorus pen ta chloride, phos-
phorus trichloride; in manu-
facture of fertilizers, pes-
ticides, incendiary shells,
smoke bombs, tracer bullets.
Med. use: formerly in
rickets, other bone diseases,
and degenerative disorders
of central nervous system
Systemic insecticide
(continued)
en
-------
APPENDIX
TABLE 4 (Continued)
PROPERTIES, TOXICITY, AND USES OF PHOSPHORUS AND SOME PHOSPHORUS COMPOUNDS
Compound
Properties
Toxicitv
Uses
Phosphine
PH.,
Gas
Odor of decay-
ing fish
bp -87.7°
mp -133°
Inhalation causes pain in
region of diaphragm, a
feeling of coldness, ver-
tigo, dyspnea, bronchitis,
edema, lung damage, con-
vulsions, coma, death.
Lethal dose for rats in
air, 60 ppm
Phosphocreatine
C4H10N305P
Med. use: In sodium salt to
treat fatigue.
Pho s phomo1ybdi c
acid
20Mo 3•2H3-
P04-48H20
Bright yellow
crystals
In weighting silks; as rea-
gent for alkaloids, uric
acid, xanthine, creatinine,
some metals, with hema-
toxylin as nerve stain in
microscopy
Phosphonium
iodide
PH4I
Large trans-
parent color-
less crystals
Readily liberates phos-
phine, which is highly
toxic, and hydriodic acid,
which is a strong irritant
In laboratory preparation of
phosphine
(continued)
Ul
CO
-------
APPENDIX
TABLE 4 (Continued)
PROPERTIES, TOXICITY, AND USES OF PHOSPHORUS AND SOME PHOSPHORUS COMPOUNDS
Compound
Properties
Toxicity
Uses
Phosphoric acid
H3P04
Unstable
orthorhombic
crystals
mp 42.35°
Concentrated solutions are
irritating to the skin and
mucous membranes
In the manufacture of super-
phosphates for fertilizers,
other phosphate salts, poly-
phosphates, detergents; as
acid catalyst in making
ethylene, purifying hydrogen
peroxide; as acidulant and
flavor in beverages of the
soft drink type; in dental
cements; in process engraving
in rustproofing of metals be-
fore painting; in coagulating
rubber latex; as analytical
reagent.
Med. use: has been used
(dilute form) as gastric and
urinary acidifier; as dress-
ing for removal of necrotic
debris of burns. Vet. use:
diluted phosphoric acid has
been used in treating lead
poisoning
Phosphoric acid
(HP03)n
Colorless,
transparent,
glass-like
solid
In dentistry for making zinc
oxyphosphate cement; as
reagent in chemical analysis
Phosphorous acid
H3P03
White crystalline
mass, garlic-
like taste
(continued)
-------
I1 ABLE 4 (Continued)
PROPERTIES, TOXICITY, AND USES OF PHOSPHORUS AND SOME PHOSPHORUS COMPOUNDS
Compound
Properties
fToxicity
Uses
Phosphorus
hemitriselenide
Dark red mass
Decomposes by
heat
Phosphorus
oxybromide
POBr0
Thin plates
Faintly orange
mp 56°
bp 193°
Phosphorus
oxychloride
POC10
Colorless,
clear liquid
bp 107°
Intensely irritating to
eyes, skin, mucous mem-
branes. Inhalation may
cause pulmonary edema
As chlorinating agent, espe-
cially to replace oxygen in
organic compounds; as solvent
in cryoscopy
Phosphorus
pentabromide
PBrc
Yellow cry-
stalline mass
mp above 100°
Toxic and corrosive
Phosphorus
pentachloride
PC1C
White to pale
yellow
mp 148°
bp 160°
Toxic and corrosive
As catalyst in manufacture of
acetylcellulose; for replac-
ing hydroxyl groups by Cl,
particularly in converting
acids into acid chlorides
Phosphorus
pentafluoride
Colorless gas
mp -93.8°
bp -84.6°
Intensely irritating to
skin, eyes, mucous mem-
branes . Inhalation may
cause pulmonary edema
(continued)
-------
APPENDIX
TABLE 4 (Continued)
PROPERTIES, TOXICITY, AND USES OP PHOSPHORUS AND SOME PHOSPHORUS COMPOUNDS
Compound
Properties
Toxicity
Uses
Phosphorus penta-
selenide
P2Se5
Black needles
Decomposes in
steam and boil-
ing water
Phosphorus
pentasulfide
P2S5
Light yellow
crystalline
mass
mp 280°
bp 523°
On contact with water, de-
composes to form hydrogen
sulfide. In air, forms
phosphorus pentoxide,
which is a strong irritant
In manufacturing safety
matches, ignition compounds,
and for introducing sulfur
into organic compounds
Phosphorus pentoxide
P2°5
Very deliques-
cent crystals
mp 580-585°
Strong irritant, corrosive
As drying and dehydrating
agent, condensing agent in
organic synthesis
Phosphorus
sulfochloride
PSC13
Fuming liquid
bp 125°
Strong irritant
Phosphorus
tribromide
Colorless
liquid
bp 175°
Toxic and corrosive
Phosphorus
trichloride
Colorless
liquid
mp -112°
bp 76°
Highly irritating and
corrosive to skin, mucous
membranes
Same uses as phosphorus oxy-
chloride; in manufacturing of
POClg, PClg, and in producing
iridescent metallic deposits
(continued)
-------
APPENDIX
TABLE 4 (Continued)
PROPERTIES, TOXICITY, AND USES OF PHOSPHORUS AND SOME PHOSPHORUS COMPOUNDS
Compound
Phosphorus
trif luoride
PF3
Phosphorus
trioxide
P2°3
Phosphorus
triselenide
P4Se3
Phosphorylcholine
JTCH3)3 *NCH2-
CH2OP03-
H2C1
Phosphotungstic
acid
24W03'2H3-
P04 • 48H20
Properti es
Colorless gas
mp -151.5°
bp -101.8°
Transparent
monoclinic
crystals
mp 23.8°
bp 173.1°
Orange-red
crystals
mp 242°
bp 360-400°
White or
slightly
yellow- green
Toxic itv
Intensely irritating to
skin, eyes, mucous mem-
branes. Inhalation may
cause pulmonary edema
Uses
Med. use: As the magnesium
salt in hepatobiliary
dysfunction
As reagent for alkaloids and
many other nitrogen bases,
phenols, albumin, peptone,
aminoacids, uric acids, urea,
blood, carbohydrates
(continued)
-------
TABLE 4 (Continued)
PROPERTIES, TOXICITY, AND USES OP PHOSPHORUS AND SOME PHOSPHORUS COMPOUNDS
Compound
Properties
Toxicity
Uses
S'-Adenylic acid
(Phosaden)
C10H14N5°7P
mp 196-2000
Med. use: adenyl compounds
have been reported to produce
coronary dilation, bradycar-
dia, hypotension, leukocyto-
sis
Phosdrin
Yellow liquid
mixture
bp 106-107.5°
Cholinesterase inhibitor
g orally in mice:
9.0 mg/kg; in rats
4.0 mg/kg
As systemic insecticide
Alpha-Hydroxybenzyl-
phosphinic acid
(Phosilit)
C?H903P
mp 110
Med. use: to counteract
toxic effects of X-ray
therapy; the sodium salt as
nutritive in convalescence
Tonophosphan
CgH13NO2PNa-3H2O
Scales or
needles
Soluble in cold
water
Med. use: As tonic
Diethyl p-nitro-
phenyl phosphate
(phosphacol)
C10H14N06P
Oily liquid
Med. use: As a parasympa-
thomimetic and miotic
Aluminum
phosphate
A1P04
White infusi-
ble powder
mp above 1,460°
As cement in admixture with
calcium sulfate and sodium
silicate; as flux for cera-
mics; in dental cements; for
special glasses. Used in
pharmacy as the gel or dried
gel. Med. use: as gastric
antacid
(continued)
-------
APPENDIX
TABLE 4 (Continued)
.PROPERTIES, TOXICITY, AND USES OF PHOSPHORUS AND SOME PHOSPHORUS COMPOUNDS
Compound
Properties
Toxicity
Uses
Aluminum
phosphide
A1P
Dark gray or
dark yellow
Must be protected from
moist air since it reacts
readily to produce phos-
phine, which is highly
toxic
As source of phosphine:
semiconductor research
in
Sodium phosphate,
dibasic
Na2HPO4
Hygroscopic
powder
Anhydrous form may cause
mild irritation to skin,
mucous membranes; causes
purging when taken in-
ternally
As a mordant in dyeing; for
weighting silk, in tanning;
in manufacture of enamels,
ceramics, detergents, boiler
compounds; as fireproofing
agent; in soldering and braz-
ing instead of borax; as rea-
gent and buffer in analytical
chemistry. Med. use: As
mild saline cathartic; has
been used in phosphorus defi-
ciency and in lead poisoning.
Vet. use: As laxative for
foals, calves
Glycerophos-
phoric acid
C3H9°6P
Clear syrupy
liquid
mp -25°
Absolute acid used to manu-
facture certain glycerophos-
phates or to impart taste to
solutions of glycerophosphates
which are generally used
medicinally
(continued)
-------
APPENDIX
TABLE 4 (Continued)
PROPERTIES, TOXICITY, AND USES OF PHOSPHORUS AND SOME PHOSPHORUS COMPOUNDS
Compound
Properties
Toxicity
Uses
Lecithin
Waxy mass
Insoluble in
water
Is an edible and digestible
surfactant and emulsifier of
natural origin. Used in mar-
garine, chocolate, and in
the food industry in general;
in pharmacueticals and cos-
metics; and for other indus-
trial uses, such as treating
leather and textiles. Med.
use: as lipotropic agent
Phosphoric acid
2,2 dichloro-
vinyl dimethyl
ester (DDVP)
C4H7C12°4P
Nonflammable
liquid
A cholinesterase inhibi-
tor
in rats 70 mg/kg
As insecticide for the con-
trol of agricultural and
household pests. Used as
0.5% spray or 0.5% bait. Vet.
use: for gastrointentinal
worms in swine, ruminants,
horses
Phosphoric acid
dimethyl ester,
ester with cis-
3-hydroxy-N,N-
dimethylcrotona-
mide
(Bidrin)
|C8H16N05P
Brown liquid
Highly toxic
See Parathion
A cholinesterase
inhibitor
orally in rats
As insecticide
50
22 mgAg
(continued)
-------
APPENDIX
TABLE 4 (Continued)
PROPERTIES, TOXICITY, AND USES OF PHOSPHORUS AND SOME PHOSPHORUS COMPOUNDS
I Compound
Properties
Toxicity
Uses
Cupric phosphate
Cu3(P04)2
Blue or olive
orthorhombic
crystals
As fungicide; as catalyst
for organic reactions; in
fertilizer; as emulsifier;
as corrosion inhibitor for
H-jPO^; protectant for metal
surfaces against oxidation
Parathion O,
O-diethyl
O-p-nitriphenyl
phosphorothionate
Yellowish
liquid
Highly toxic
Acute: anorexia, nausea,
vomiting, diarrhea, ex-
cessive salivation, pupil-
lary constriction, bron-
choconstriction, muscle
twiching, convulsions,
coma, respiratory failure,
Effects are cumulative.
Special precautions
necessary to prevent in-
halation and skin conta-
mination
As agricultural insecticide
Ammonium sodium
phosphate
NaNH HP04
Odorless
crystals
Mp approx 80°
As a reagent for determina-
tion of Mg and Zn, and in
blowpipe analysis; for
standardizing uranium solu-
tions; in the preparation
of ammonium phosphate and
ammonium molybdate stock
solutions
(continued')
-------
TABLE 4 (Continued)
PROPERTIES, TOXICITY, AND USES OF PHOSPHORUS AND SOME PHOSPHORUS COMPOUNDS
Compound
Properties
Toxicity
Uses
Ferric phosphate
FePO,
White, gray, or
pink crystals
As food and feed supplement,
particularly in bread en-
richment; as fertilizer
Malathion
C10H19°6PS2
Deep brown to
yellow liquid
Produces symptoms similar
to those for parathion.
Malathion is, however,
considered to be less
toxic
As insecticide, particularly
effective against pear psylla,
red spider mites, and aphids;
appears to be about 100 times
less toxic to warm-blooded
animals than parathion, about
two to four times less toxic
to insects. Vet use:
ectoparasiticide for horn
fly, lice in dairy cattle;
horn fly, lice, ticks in
btef cattle; lice, sheep ked
ticks in sheep and goats;
lice, sarcoptic mange in
swine; lice, ticks, mites
in poultry
-------
68
APPENDIX
TABLE 5
COMPARATIVE ACUTE TOXICITY OF CHOLINERGIC
ORGANOPHOSPHORUS INSECTICIDES IN NORMAL MALE AND FEMALE RATS
52
Insecticide
Phosdrin
Systox
Guthion
Di-Syston
Parathion
Methyl
OMPA
Co-Ral
EPN
Trithion
Delnav
Ethion
Polex
Ronnel
Ma lath ion
Number
Male
35
35
37
35
57
52
78
36
70
72
75
36
54
38
48
of Rats
Female
35
60
37
32
41
44
39
45
44
34
32
37
44
25
39
LD50±SE*
Male
3.2*0.3
3.9*0.1
4.0±0.5
6 . 7± 0 . 6
8.1+-0.4
9.3±0.8
9.6±0.4
14.711.4
23.9+1.1
27.0+0.8
33.2+2.2
34.5+5.9
67.7+5.0
118.0116.2
193.0+25.9
(mgAg)
Female
1.2*0.1
1.4±0.1
8.7±0.6
2.1*0.1
2.5±0.4
7.0+0.6
28.7±1.3
7.510.4
7.3+0.5
10.1+0.8
17.2+0.9
25.911.8
124.018.8
2822.6+137.4
619.4125.0
*SE=standard error.
-------
TABLE 6
COMPARATIVE TOXICITIES OF SOME PHOSPHORUS
COMPOUNDS FOR EXPERIMENTAL ANIMALS
Toxic Substance
p-Nitrophenyldiethyl
thiophosphate (E.605)
isomer I
isomer II
p-Nitrophenyldiethyl
phosphate (E.600)
p-Nitrophenyldiethyl
thiophosphate
.
M
4-Methyl-7-hydroxy-
coumaryldi ethyl
thiophosphate (E.838)
Dimethyl p-nitrophenyl
thiophosphate
11
„
11
»
Concentration
Value
(ppm body wt)
3.0
1.2
0.5
0.4
10.0
II
II
II
15.0
II
II
II
10.0
II
II
11
15.0
II
II
II
Route6
iv
"
11
ip
n
n
n
iv
'•
11
"
„
»
Subiect Effect Ref .
Sinqle Exposure
Rat, male
"
Rabbit
.,
ll
ll
ll
ll
M
II
II
II
II
ll
ll
II
II
ll
LD
n
n
10EDa83
10ED8b
11ED66
HED9b
40ED81
40ED20b
20ED94
20ED26b
30ED97
30EDOb
10ED67
10EDOb
40ED64
40ED8b
10ED80
10ED6b
10ED8D
10ED6b
40ED65
40ED5D
1
II
II
II
II
:;
n
M
n
n
n
i
M
ii
•
ii
n
ti
i
(continued)
-------
APPENDIX
TABLE 6 (Continued)
COMPARATIVE TOXICITIES OF SOME PHOSPHORUS
COMPOUNDS FOR EXPERIMENTAL ANIMALS
Toxic Substance
Di-isopropyl p-nitro-
phenyl thiophosphate
"
Bis -dime thylaminof luo-
rophosphine oxide
"
11
n
11
11
p-Nitrophenyldiethyl
thiophosphate (E.605)
isomer I
isomer III
p-Nitrophenyldiethyl
phosphate (E.600)
4-Methyl-7-hydroxy-
phosphate
bis-dimethylaminoglu-
orophosphine oxide
11
11
Phosphorus oxychloride
Concentration
Value
(ppm body wt)
15.0
II
20.0
II
II
II
"
11
1.7X10"4
2.5X10-7
2.8X10"8
2.0X10"8
5.0X10"9
4.0X10"5
7.0X10"2
7.0X10"4
mq/m
61.3
56.3
Route6
iv
11
1
"
"
"
11
"
sol
II
II
II
II
II
"
11
ih
Sub -i act Effect Ref.
Sinqle Exposure
Rabbit
M
ll
II
11
"
1
"
Sheep0
11
II
1
11
Ratd
"
11
4 hours
Rat, female
20
II
10ED34
10ED21b
7 EDS 8
7ED31to
20ED86
20EDOb
42ED89
42EDOb
ED50b
II
II
11
II
b
mm ED,.,-,
n ->(J
"
LD50
1
"
n
"
n
11
II
II
11
11
II
1
"
1
II
11
79
"
"
a
(Continued)
-------
APPENDIX
TABLE 6 (Continued)
COMPARATIVE TOXICITIES OF SOME PHOSPHORUS
COMPOUNDS FOR EXPERIMENTAL ANIMALS
Toxic Substance
Phosphorus oxychloride
M
Phosphorus trichloride
Phosphorus trichloride
(vapors/aerosols )
11
Concentration
Value
(Moles)
66.6
52.4
132.1
152.4
63.5
132.0
Route
ih
ll
11
II
ll
li
Subiect Effect Ref.
Single Exposure
Guinea pig
male, 10
11
Rat, female
20
11
Guinea pig
male, 10
II
LD
II
II
11
II
II
1
ll
ll
H
ll
II
aED = Effective dose for inhibition of cholinesterase. The sight-hand subscript
indicates the percent inhibition of cholinesterase and the left-hand one showes time
(min) after injection or of incubation.
in vitro inhibition.
°Incubation at 37° C, sheep red cells.
Brain, auxiliary glands, red cells, brain serum, and heart.
eiv = intravenous; ip = intraperitoneal; ih = inhalation; sol = solution
-------
APPENDIX
TABLE 7
PRODUCTION OF PHOSPHORUS CHEMICALS
(Thousand Short Tons)
19,20
Phosphorus Chemicals
Phosphoric acid, total
Phosphorus, elemental
Phosphorus oxychloride
Phosphorus pentasulfide
Potassium pyrophosphate
Calcium phosphate, basic
Sodium phosphate, tripoly
Potassium pyrophosphate
1964a
3,283
504
27
42
52
242
886
52
1965a
3,905
550
27
50
55
263
923
55
1966a
4,549
566
31
54
53
290
1,001
53
1967b
4,764
583
33
45
53
380
1,046
53
. 1968°
5,202
620
34
58
63
339
1,072
63
1969C
5,690
652
36
64
69
356
1,117
69
aU.S. Department of Commerce.
Preliminary data.
CC & EN computer forecasts.
-------
73
TABLE 8
GROWTH OF PHOSPHORIC ACID INDUSTRY IN UNITED STATES2
(ton/year 100% P->OC
Year Thermal process Wet process
1941
1942
1943
1944
1945
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
108,494
104,655
103,418
111,157
132,149
191,911
211,578
259,677
295,073
330,096
357,622
462,580
506,774
540,025
570,235
632,954
657,372
740, 747
762,531
844, 761
869,805
947,293
1,007,624
l,007,941a
131,521
118,970
127,248
141,141
132,599
174,987
220,828
245,427
299,152
338,426
388,908
496,152
631,252
774,998
811,770
936,129
1,033,205
1,140,658
1,324,695
1,409,173
1,576,976
1,957,476
2,275,418
2,837,119
aSubject to revision
-------
TABLE 9
THERMAL-PROCESS PHOSPHORIC ACID ESTABLISHMENTS
IN UNITED STATES2
74
State
Company
Location
Alabama
California
Tennessee Valley Authority Wilson Dam
Colorado
Georgia
Idaho
Illinois
Indiana
F M C Corporation
Monsanto Company
Stauffer Chemical Company
Stauffer Chemical Company
Colorado Fuel and Iron
Corporation
Monsanto Company
El Paso Natural Gas Company
Monsanto Company
Stauffer Chemical Company
Stauffer Chemical Company
Hooker Chemical Company
Mobil Chemical Company
Newark
Long Beach
Richmond
South Gate
Pueblo
(not operating)
Augusta
Georgetown
(not operating)
Sauget
Chicago Heights
South Chicago
Jeffersonville
Gary
Kansas
Massachusetts
Michigan
Montana
New Jersey
New York
Ohio
F M C Corporation
Hooker Chemical Company
Monsanto Company
Stauffer Chemical Company
Agrigo Chemical Company
Continental Oil Company
F M C Corporation
Monsanto Company
Hooker Chemical Company
Mobil Chemical Company
Monsanto Company
Lawrence
Adams
Trenton
Butte
Carteret
Carteret
Carteret
Kearny
Niagara Falls
(not operating)
Fernald
Addyston
(continued)
-------
75
TABLE 9 (Continued)
THERMAL-PROCESS PHOSPHORIC ACID ESTABLISHMENTS
IN UNITED STATES2
State Company Location
Pennsylvania Stauffer Chemical Company Morrisville
South Carolina Mobil Chemical Company Charleston
Tennessee Hooker Chemical Company Columbia
Stauffer Chemical Company Nashville
Texas Hooker Chemical Company Dallas
Wyoming F M C Corporation Green River
------- |