Sodium Salts of Polyphosphates Supply Chain - Executive Summary
Sodium Salts of Polyphosphates
Direct Use Chemical
Sodium Hexametaphosphate: Na6(P03)6
Sodium Tripolyphosphate: Na5 P3Oi0
(solid or liquid) 0
Inputs to Manufacturing Process:
Monosodium Phosphate
Disodium Phosphate
J* Derivative Water Treatment Chemicals:
*
None
% of Total Domestic Consumption
Attributed to Water Sector:
Approximately 40%
Understanding Chemical Supply Chains
Map of Suppliers & Manufacturers
A. Product Family:
Phosphate
CAS No.: 68915-31-1
7758-29-4
2 Shelf Life:
12-18 Months
— RISK OF SUPPLY DISRUPTION (Assessed in 2022)
RISK RATING: Moderate-Low
«-Low Moderaf
Range%
RISK DRIVERS
Strong reliance on interna-
tional market for manufactur-
ing inputs, primarily phos-
phoric acid. Increased compe-
tition and reliance on imports
have challenged phosphate
manufacturers. Regional sup-
ply disruptions have occurred
between 2000 and 2022.
RISK PARAMETERS
Criticality: High. Essential for corro-
sion control.
Likelihood: Moderate-Low Previous
disruptions in supply that impacted
manufacturing inputs and supply.
Vulnerability: Moderate-High. Lim-
ited domestic manufacturing and
reliance on international market for
inputs and finished product.
MANUFACTURING PROCESS
Water Treatment Applications
Alone or blended for metal
sequestration and scale inhibition
Other Applications
Clay and ore processing
Cleaning product formulation
Food processing
DOMESTIC PRODUCTION AND CONSUMPTION, AND INTERNATIONAL TRADE
Domestic Manufacturing Locations (2015):
Sodium Hexametaphosphate: 2 locations
Sodium Tripolyphosphate: 3 locations
(§> International Trade (2019)
Primary Trading Partner (Imports): Canada
Primary Trading Partner (Exports): Canada
Domestic Production and Consumption
Total domestic manufacturing of sodium tripolyphosphate
reported under the TSCA CDR was approximately 0.014 M kg in
2019. Significantly, most domestic manufacturers of sodium
tripolyphosphate and sodium hexametaphosphate did not report
production. Due to this data gap and differences in reporting
between production and trade data for sodium hexametaphos-
phate, U.S. consumption could not be estimated.
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Sodium Salts of Polyphosphates Supply Chain - Full Profile
Product Description
Sodium salts of polyphosphates are a class of phosphate salts with varying chemical formulas, all derived from
phosphoric acid. Sodium polyphosphates are commonly used alkali metal polyphosphates in water treatment as
blended phosphates for scale inhibition and metal sequestration. Two commonly used polyphosphates; sodium
tripolyphosphate (STPP) and sodium hexametaphosphate (SHMP) are featured in this profile.
Use in Water Treatment
Polyphosphates are used alone or blended with orthophosphates for scale inhibition and sequestration of
metals to reduce metals release in distribution systems. When sold as a commercial chemical product for water
treatment, polyphosphates are sold in specific form, such as sodium tripolyphosphate and sodium
hexametaphosphate or, more commonly, as a trademarked blend of orthophosphates and polyphosphates.
Use as a Precursor to Other Water Treatment Chemicals
Sodium salts of polyphosphates are not used to manufacture other water treatment chemicals.
Other Applications
Sodium tripolyphosphate and sodium hexametaphosphate have a range of applications. STPP is widely used in
water treatment, dishwater detergents, and food processing (USITC, 2009). SHMP is used in water treatment,
clay processing, cleaning products, and food processing (USITC, 2018).
Primary Industrial Consumers
Historically, water treatment has been the primary use for SHMP (40.7%), followed by clay processing, copper
ore processing, drilling muds, and paper production ( 22.5%); industrial and institutional cleaners (16.8%); meat,
seafood, and poultry processing (15.3%); bath salts (3.5%); and toothpastes (1.2%) (USITC, 2018). Water
treatment, detergent formulation, and food processing are primary uses of STPP (USITC, 2009).
Manufacturing, Transport, & Storage
Manufacturing Process
This profile focuses on two sodium polyphosphates widely used alone or in blended solutions for water
treatment: SHMP and STPP. Production of these polyphosphates starts with monosodium phosphate or a
combination of monosodium and disodium phosphate and proceeds with heating and polymerization. The
overall equations for the most common manufacturing processes for SHMP and STPP are outlined in Figure 1
and Figure 2, respectively.
Sodium hexametaphosphate is produced from a solution of monosodium phosphate. Monosodium phosphate is
heated to form disodium pyrophosphate. This is in turn heated to form molten sodium hexametaphosphate,
which solidifies into a glassy sheet as it cools. The sheet is milled to produce a granular or powdered product
(AWWA, 2006; USITC, 2018).
Sodium tripolyphosphate is produced from a mixture of mono- and disodium phosphates. The mixed
phosphates are calcined, which forces the mono- and disodium phosphate molecules to react and condense,
forming polymers in a specific size range. The cooled, dried product is milled into a granular or powdered
product (AWWA 2017; USITC, 2009).
EPA 817-F-22-048 | December 2022
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Sodium Salts of Polyphosphates Supply Chain - Full Profile
Step 1
Monosodium Phosphate +
Heat -
> Disodium Pyrophosphate + Water
2NaH2P04 +
Heat —
> Na2H2P207 + H20
Step 2
Disodium Pyrophosphate +
Heat -
-> Sodium Hexametaphosphate + Water
3Na2H2P207 +
Heat
-> Na6(P03)6 + 3H20
Figure 1. Chemical Equation for the Reaction to Manufacture Sodium Hexametaphosphate
Monosodium Phosphate + Disodium Phosphate —
Sodium Tripolyphosphate +
Water
2NaH2P04 + Na2HP04 -
~ Na5P3Oio +
H20
Figure 2. Chemical Equation for the Reaction to Manufacture Sodium Tripolyphosphate
Product Transport
STPP and SHMP, primarily supplied in solution but also available as a solid or powder, are widely transported in
container and bulk by truck, rail, barge, and ship.
Storage and Shelf Life
Sodium hexametaphosphate and sodium tripolyphosphate are stable and generally non-reactive. When stored
properly, they can have a shelf life from 12 to 18 months (Carus, 2013; Carus, 2017; ICL, 2015; Innophos, 2019).
Domestic Production & Consumption
Domestic Production
Production data was collected from the 2020 Toxic Substances Control Act (TSCA) Chemical Data Reporting
(CDR) for the year 2019, while trade data was collected from the USITC Dataweb, as shown in Table 1.
Production data are specific to SHMP and STPP. Trade data is available for STPP, however SHMP may be
imported under several harmonized tariff schedule (HTS) codes. The SHMP HTS codes are not specific to SHMP
and also include other phosphates and blends (USTIC, 2018). One of these codes has been referenced in Table 1.
Table 1. Sodium Hexametaphosphate and Sodium Tripolyphosphate Production and Trade Data Sources
Production and Trade Data
Category
Data Source
Identifier
Description
Domestic Production
2020 EPA Chemical
Data Reporting
CAS No.: 68915-31-1
CAS No.: 7758-29-4
Sodium Hexametaphosphate
Sodium Tripolyphosphate
Imports and Exports
U.S. International
Trade Commission
HTS Code: 2835.39.50
HS Code: 2835.31
Polyphosphates (other than sodium (or
sodium tripolyphosphate) of potassium)
(including sodium hexametaphosphate)
Sodium Tripolyphosphate
Of the 27 facilities reporting as part of CDR in 2019, only three locations indicated domestic production of STPP,
and of those only one reported a production quantity. Total reported U.S. domestic production of STPP for
commercial sale was approximately 0.014 million kg (M kg) in 2019 (EPA, 2020). Of the 11 facilities reporting
SHMP production or import as part of CDR in 2019, only three locations indicated domestic production of SHMP,
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Sodium Salts of Polyphosphates Supply Chain - Full Profile
and of those only one reported a production quantity. This facility indicated that production of SHMP was
primarily used at the manufacturing site. The company identifying SHMP production quantity, Nalco,
manufactures SHMP for captive consumption and is not known to sell any product commercially (USITC, 2018).
The primary domestic manufacturer for both STPP and SHMP is ICL Specialty Products. The number of domestic
manufacturing locations shown in Figure 3 represents operating facilities as of 2015 (EPA, 2016). Supply of
NSF/ANSI Standard 60 certified STPP and SHMP for use in drinking water treatment is distributed throughout
the U.S. (NSF International, 2021). For a more current listing of manufacturing locations and supplier locations,
visit the U.S. Environmental Protection Agency's (EPA's) Chemical ocator Tool (EPA, 2022a).
Domestic Supply and Manufacturing of Sodium Tripolyphosphate and Sodium Hexametaphosphate
Sodium Hexametaphosphate
• 73 NSF/ANSI Standard 60 Certified Suppliers (NSF International, 2021)
0 2 Domestic Manufacturing Locations (EPA Chemical Data Reporting, 2016)
Sodium Tripolyphosphate
O 15 NSF/ANSI Standard 60 Certified Suppliers (NSF International, 2021)
0 3 Domestic Manufacturing Locations (EPA Chemical Data Reporting, 2016)
•
1\
Figure 3. Domestic Supply and Manufacturing of Sodium Hexametaphosphate and Sodium Tripolyphosphate
Domestic Consumption
Due to differences in reporting for production and trade data, as well as the significant number of producers
that did not report production data under the CDR, U.S. consumption of SHMP could not be estimated.
Consumption of STPP was not estimated due to the significant number of producers that did not report
production.
Trade &Ta riffs
Worldwide Trade
Worldwide import and export data for sodium tripolyphosphate are reported through the World Bank's World
Integrated Trade Solutions (WITS) software, as a category specific to STPP. In 2021, the U.S. ranked tenth
worldwide in total exports and first in total imports of STPP. In 2021, China ranked first worldwide in total
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Sodium Salts of Polyphosphates Supply Chain - Full Profile
exports (WITS, 2022) as shown in Table 2. As previously noted, trade reporting for sodium hexametaphosphate
may be covered by several trade categories, none of which are specific to sodium hexametaphosphate.
Table 2. WITS Worldwide Export and Import of Sodium Tripolyphosphate in 2021
2021 Worldwide Trade
Sodium Tripolyphosphate (HS Code 2835.31)
Top 5 Worldwide Exporters
Top 5 Worldwide Importers
China
177 M kg
United States
54 M kg
Russian Federation
77 M kg
India
49 M kg
Belgium
64 M kg
Indonesia
29 M kg
Tunisia
43 M kg
Brazil
19 M kg
Canada
43 M kg
Peru
15 M kg
Domestic Imports and Exports
Domestic import and export data are reported by USITC in a category specific to STPP. Figure 4 summarizes
imports for consumption1 and domestic exports2 of STPP between 2015 and 2020. During this period, the overall
quantity of imports remained relatively steady, with imports consistently exceeding exports, while the quantity
of exports varied, with a high in 2017. Over this five-year period, Canada was the primary recipient of domestic
exports and the primary source of imports (USITC, 2022a).
Domestic Trade of Sodium Tripolyphosphate
60 HTS Code 2835.31
50
_ 40
CUD
£ 30
0
1 20
10
I
t/) tO LO CO tO tO CO
2015 2016 2017 2018 2019 2020
¦ Imports from Canada ¦ Exports to Canada
¦ Imports from Belgium ¦ Exports to Australia
I Imports from Other Countries Exports to Other Countries
Figure 4. USITC Domestic Import and Export of Sodium Tripolyphosphate between 2015 and 2020
1 Imports for consumption are a subset of general imports, representing the total amount cleared through customs and entering
consumption channels, not anticipated to be reshipped to foreign points, but may include some reexports.
2 Domestic exports are a subset of total exports, representing export of domestic merchandise which are produced or manufactured in
the U.S. and commodities of foreign origin which have been changed in the U.S.
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Sodium Salts of Polyphosphates Supply Chain - Full Profile
Tariffs
There is a 1.4% general duty for import of STPP and an additional 25% duty on imports from China (USITC,
2022b), as summarized in Table 3.
Table 3. 2020 Domestic Tariff Schedule for Sodium Tripolyphosphate
HS Code
General Duty
Additional Duty - China
(Section 301 Tariff List)
Special Duty
2835.31
1.4%
25%
Free (A, AU, BH, CL, CO, D, E, IL, JO, KR, MA, OM,
P, PA, PE, S, SG)3
Market History & Risk Evaluation
History of Shortages
Disruptions to phosphoric acid production and the supply chain for phosphate rock can have a significant impact
on availability of phosphoric acid and phosphates used in corrosion control applications. The increased demand
for phosphoric acid and phosphates for use in fertilizers and animal feed has led to price increases and supply
disruptions. Domestic manufacturers and suppliers of phosphate-based water treatment chemicals oftentimes
rely on the international market for supply of phosphate rock and phosphoric acid and may encounter persistent
challenges in obtaining these raw materials. Imports of finished product (SHMP and STPP) are also important for
meeting domestic demand. This has led to repeated shortages of phosphate-based water treatment chemicals.
In 2021, disruptions in international trade caused by the COVID-19 pandemic severely challenged these
manufacturers and domestic suppliers.
Risk Evaluation
The complete risk assessment methodology is described in Understanding Water Treatment Chemical Supply
Chains and the Risk of Disruptions (EPA, 2022b). The risk rating is calculated as the product of the following three
risk parameters:
Risk = Criticality x Likelihood x Vulnerability
Criticality Measure of the importance of a chemical to the water sector
Likelihood Measure of the probability that the chemical will experience a supply disruption in the
future, which is estimated based on past occurrence of supply disruptions
Vulnerability Measure of the market dynamics that make a chemical market more or less resilient to
supply disruptions
The individual parameter rating is based on evaluation of one or more attributes of the chemical or its supply
chain. The ratings and drivers for these three risk parameters are shown below in Table 4.
3 Symbols used to designate the various preference programs and trade agreements. A full list of special trade agreements and
associated acronyms can be found at https://help.cbp.gov/s/article/Article-310?language=en US and the General Notes Section of the
Harmonized Tariff Schedule https://hts.usitc.gov/current
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Sodium Salts of Polyphosphates Supply Chain - Full Profile
Table 4. Supply Chain Risk Evaluation for Sodium Salts of Polyphosphates
Risk Parameter Ratings and Drivers
1
1 1
ICriticality High
(Vulnerability Moderate-High 1
Sodium salts of polyphosphates are
essential to the water sector and have
widespread application for corrosion
control.
The water sector has experienced
regional supply disruptions in the
past. Concerns are primarily due to
increased competition and reliance on
imports for inputs (phosphoric acid,
and mono- and disodium phosphate).
Domestic manufacturing is limited;
however supply is widespread. There
is a significant reliance on imports for
both inputs and finished product.
Risk Rating: Moderate-Low
te-Low M°deraf
\S"° Rar>ge 'e/>
References
American Water Works Association (AWWA), 2006. B502, Sodium Polyphosphate, Glassy (Sodium
Hexametaphosphate). Denver, CO: American Water Works Association.
American Water Works Association (AWWA), 2017. B503, Sodium Tripolyphosphate. Denver, CO: American
Water Works Association.
Carus Corporation (Carus), 2013. AQUA MAG® Blended Phosphate: Data Sheet, retrieved from
https://www.carusllc.com/wp-content/uploads/DW-AQUA-MAG-Data-Sheet.pdf
Carus Corporation (Carus), 2017. Phosphates: Technical Information, retrieved from
https://www.battlecreekmi.gov/DocumentCenter/View/7614/Phosphate-FAQs
EPA, 2016. 2016 TSCA Chemical Data Reporting, retrieved from https://www.epa.gov/chemical-data-
reporting/access-cdr-data#2016
EPA, 2020. 2020 TSCA Chemical Data Reporting, retrieved from https://www.epa.gov/chemical-data-
reporting/access-cdr-data#2020
EPA, 2022a. Chemical Suppliers and Manufacturers Locator Tool, retrieved from
https://www.epa.gov/waterutilityresponse/chemical-suppliers-and-manufacturers-locator-tool
EPA, 2022b. Understanding Water Treatment Chemical Supply Chains and the Risk of Disruptions, retrieved
from https://www.epa.gov/waterutilitvresponse/risk-disruptions-supplv-water-treatment-chemicals
ICL Performance Products (ICL), 2015. Shelf life and storage conditions statement, retrieved from
https://ingredi.com/content/pdfs/TSPc Shelf life.pdf
Innophos, 2019. Safety Data Sheet for Curafos® Sodium Tripolyphosphate, retrieved from
https://chemistryconnection.com/sds/data/pdf/Sodium Tripolyphosphate SDS.pdf
NSF International, 2022. Search for NSF Certified Drinking Water Treatment Chemicals, retrieved from
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Sodium Salts of Polyphosphates Supply Chain - Full Profile
https://info.nsf.org/Certified/PwsChemicals/
U.S. International Trade Commission (USITC), 2009. Certain Sodium and Potassium Phosphate Salts from
China, retrieved from https://www.usitc.gov/publications/701 731/pub4110.pdf
U.S. International Trade Commission (USITC), 2018. Sodium Hexametaphosphate from China, retrieved from
https://www.usitc.gov/publications/701 731/pub4840.pdf
U.S. International Trade Commission (USITC), 2022a. USITC DataWeb, retrieved from
https://dataweb.usitc.gov/
U.S. International Trade Commission (USITC), 2022b. Harmonized Tariff Schedule (HTS) Search, retrieved
from https://hts.usitc.gov/
World Integrated Trade Solutions (WITS), 2022. Trade Statistics by Product (HS 6-digit), retrieved from
https://wits.worldbank.org/trade/countrv-bvhs6product.aspx?lang=en#void
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