Zinc Orthophosphate Supply Chain - Executive Summary

Zinc Orthophosphate

Direct Use Chemical

Zn3(P04)2

(liquid)

Inputs to Manufacturing Process:

Zinc

Phosphoric Acid

J* Derivative Water Treatment Chemicals:
*

None

% of Total Domestic Consumption
Attributed to Water Sector:

Less than 10%

Understanding Chemical Supply Chains
Map of Suppliers & Manufacturers

A. Product Family:
Zinc, Phosphate

CAS No.:
7779-90-0

2 Shelf Life:
24 Months

— RISK OF SUPPLY DISRUPTION (Assessed in 2022)

RISK RATING: Moderate-Low

ate-Low Modern



RISK DRIVERS

Strong reliance on internation-
al market for manufacturing
inputs, primarily phosphoric
acid. Increased competition
and reliance on imports have
challenged phosphate manu-
facturers. Regional phosphoric
acid supply disruptions have
occurred between 2000 and
2022.

RISK PARAMETERS

Criticality: Moderate-High.
Essential for corrosion control.

Likelihood: Moderate-High.
Previous disruptions in supply that
impacted manufacturing inputs.

Vulnerability: Low. Distributed
domestic manufacturing and
supply, however reliance on
international market for inputs.

MANUFACTURING PROCESS

Water Treatment Applications

Corrosion control

Other Applications

Corrosion inhibitor for metals and

coatings

Dental cements

DOMESTIC PRODUCTION AND CONSUMPTION, AND INTERNATIONAL TRADE

Domestic Manufacturing Locations (2015):
8, distributed throughout the U.S.

(§> International Trade (2019)

Primary Trading Partner (Imports): Germany
Primary Trading Partner (Exports): Canada

Domestic Production and Consumption

Total domestic manufacturing of zinc orthophosphate reported
under the TSCA CDR was approximately 0.66 M kg in 2019. Sig-
nificantly, several domestic manufacturers of zinc orthophos-
phate did not report production. Due to this data gap and differ-
ences in reporting between production and trade data, U.S. con-
sumption of zinc orthophosphate could not be estimated.

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Zinc Orthophosphate Supply Chain - Full Profile

Product Description

Zinc orthophosphate (Zn3(P04)2), also known as zinc phosphate, is widely used in corrosion control coatings on
metal surfaces. It is primarily manufactured through the reaction of zinc and phosphoric acid. The majority of
zinc orthophosphate manufactured in the U.S. is used in metal coating applications.

Use in Water Treatment

Zinc orthophosphate is used for corrosion control in distribution system piping. Zinc orthophosphate may be
sold alone as a commercial chemical product for water treatment, or, more commonly, as a component of a
trademarked blend of zinc phosphates along with other orthophosphates and polyphosphates (AWWA, 2006).

Use as a Precursor to Other Water Treatment Chemicals

Zinc orthophosphate is not used as a precursor in the commercial manufacture of other water treatment
chemicals.

Other Applications

Zinc orthophosphate is widely used in many industries and a variety of settings as a corrosion inhibitor for
metals and coatings. It is also used in cement applications, primarily dental cements (ATSDR, 2005; NCBI, 2021).

Primary Industrial Consumers

Zinc orthophosphate is primarily used for preparing metal coatings and in dental cements. While the percentage
of consumption accounted for by water treatment is unknown, it is believed to be less than 10% based on
estimates of other uses.

Manufacturing, Transport, & Storage

Manufacturing Process

Phosphoric acid and a source of zinc are the raw materials commonly used to produce zinc orthophosphate.
There are numerous methods to produce zinc orthophosphate on a commercial scale, most commonly by mixing
zinc oxide and phosphoric acid or a zinc salt (e.g., zinc chloride) and sodium orthophosphate or phosphoric acid,
in various zinc to phosphate ratios. Zinc salts are formed by reacting zinc oxide, obtained from zinc-bearing ores
which have undergone beneficiation steps and removal of impurities, with hydrochloric acid or sulfuric acid. Zinc
salts are subsequently mixed with phosphoric acid, filtered, and provided as a liquid or subsequently dried to
provide a solid product. The general equations for these reactions are shown in Figure 1.

Method 1







Zinc Chloride

+ Phosphoric Acid

—> Zinc Phosphate

+ Hydrochloric Acid

3ZnCI2

+ 2H3P04

—> Zn3(P04)2

+ 6HCI

Method 2







Zinc Sulfate

+ Phosphoric Acid -

-> Zinc Phosphate

+ Sulfuric Acid

3ZnS04

+ 2H3PO4

> Zn3(P04)2

+ 3H2S04

Method 3







Zinc Oxide +

Phosphoric Acid —>

Zinc Phosphate +

Water

3ZnO +

2H3PO4 ->

Zn3(P04)2 +

3H20

Figure 1. Chemical Equations for the Reactions to Manufacture Zinc Orthophosphate

EPA 817-F-22-054 | December 2022

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Zinc Orthophosphate Supply Chain - Full Profile

Product Transport

Zinc orthophosphate, primarily supplied as a solution, is transported in container and bulk by truck, rail, barge,
and ship.

Storage and Shelf Life

Zinc orthophosphate solutions are often produced as propriety mixtures. When stored properly, zinc
orthophosphate solutions, though varied in composition, may have a shelf life up to approximately 24 month
(Carus, 2001; Carus, n.d.).

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 U.S. International Trade Commission (USITC)
Dataweb, as shown in Table 1. While production data is specific to zinc orthophosphate, trade data includes zinc
orthophosphate as part of a class of phosphates other than aluminum, calcium, potassium, sodium,
triammonium, andtrisodium phosphates.

Table 1. Zinc Orthophosphate Production and Trade Data Sources

Production and Trade Data

Category

Data Source and Date

Identifier

Description

Domestic Production

2020 TSCA Chemical Data
Reporting

CAS No.: 7779-90-0

Zinc Phosphate

Imports and Exports

U.S. International Trade
Commission

HS Code: 2835.29.51

Phosphates other than aluminum,
calcium, potassium, sodium,
triammonium, and trisodium

Total domestic manufacturing of zinc orthophosphate reported under the CDR was approximately 0.66 M kg in
2019 (EPA, 2020); however, several domestic manufacturers claimed confidential business information and did
not report production volumes to EPA, including historic significant domestic manufacturers ICL Specialty
Products and the Thatcher Company. Most zinc orthophosphate production facilities produce zinc
orthophosphate blends for metal coating. Carus Corporation is the largest producer of zinc orthophosphate
blends for water treatment reporting production in 2019. The number of domestic manufacturing locations
shown in Figure 2 represents operating facilities as of 2015 (EPA, 2016). Supply of NSF/ANSI Standard 60
certified zinc orthophosphate for use in drinking water treatment is widely 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 Locator Tool (EPA, 2022a).

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Zinc Orthophosphate Supply Chain - hull Profile

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Domestic Supply and Manufacturing of Zinc Orthophosphate
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Figure 2. Domestic Supply and Manufacturing of Zinc Orthophosphate
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 2020 CDR, U.S. consumption of zinc orthophosphate could not be
estimated. Domestic production of zinc orthophosphate represents a small quantity when compared to the
import and export volume for the category of phosphates including zinc orthophosphate.

Trade &Tariffs
Worldwide Trade

Worldwide import and export data for zinc orthophosphate are reported through the World Bank's World
Integrated Trade Solutions (WITS), as a category representing a class of compounds including phosphates other
than sodium, potassium, and calcium phosphates. In 2021, the U.S. ranked third worldwide in total exports and
fifth in total imports of phosphates other than sodium, potassium, and calcium phosphates. In 2021, China
ranked first worldwide in total exports (WITS, 2022), as shown in Table 2. Import and export data specific to zinc
orthophosphate are unavailable from the referenced sources.

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Zinc Orthophosphate Supply Chain - hull Profile

Table 2. WITS Worldwide Export and Import of Phosphates Other than Sodium, Potassium, and Calcium, in 2021

2021 Worldwide Trade
Phosphates Other than Sodium, Potassium, and Calcium (HS Code 2835.29)

Top 5 Worldwide Exporters	Top 5 Worldwide Importers

Germany

30 M kg

Malaysia

42 M kg

Malaysia

9 M kg

Belgium

13 M kg

United States

6M kg

United Kingdom

10 M kg

Sweden

5 M kg

Germany

9 M kg

Netherlands

5 M kg

United States

8M kg

Domestic Imports and Exports

Domestic imports and export data are reported by USITC in a category including phosphates other than
aluminum, calcium, potassium, sodium, triammonium, and trisodium. Figure 3 summarizes imports for
consumption1 and domestic exports2 of phosphates other than aluminum, calcium, potassium, sodium,
triammonium, and trisodium between 2015 and 2020. During this period, the overall quantity of exports and
imports remained relatively steady, with domestic exports exceeding imports for consumption. Over this five-
year period, Canada was the primary recipient of domestic exports while Germany was the primary source of
imports (USITC, 2022a).

Domestic Trade of Phosphates (other than aluminum, calcium, potassium, sodium,

triammonium, and trisodium)

HTS Code 2835.29.51

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Imports from Other Countries Exports to Other Countries

Figure 3. USITC Domestic Import and Export of Phosphates Other than Aluminum, Calcium, Potassium,
Sodium, Triammonium, and Trisodium 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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Zinc Orthophosphate Supply Chain - Full Profile

Tariffs

There is a 4.1% general duty for import of the category of phosphates including zinc orthophosphate and an 25%
additional duty on imports from China (USITC, 2022), as summarized in Table 3.

Table 3. 2021 Domestic Tariff Schedule for Phosphates Other than Aluminum, Calcium, Potassium, Sodium,
Triammonium, and Trisodium

HS Code

General Duty

Additional Duty - China
(Section 301 Tariff List)

Special Duty

2835.29.51

4.1%

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 of phosphate rock can have a significant impact on
availability of phosphates used in corrosion control applications. The increased demand for phosphoric acid for
use in fertilizers 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.
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.

Risk Evaluation

The complete risk evaluation 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.eov/s/article/Article-310?laneuaee=en US and the General Notes Section of the
Harmonized Tariff Schedule https://hts.usitc.eov/current

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Zinc Orthophosphate Supply Chain - Full Profile

Table 4. Supply Chain Risk Evaluation for Zinc Orthophosphate

Risk Parameter Ratings and Drivers





1

ICriticality Moderate-High

1 Likelihood Moderate-High 1

(Vulnerability Low 1

Zinc orthophosphate is broadly used
in corrosion control. It is not used to
manufacture other water treatment
chemicals.

Phosphoric acid is a critical input in
zinc orthophosphate manufacturing.
The water sector has experienced
regional phosphoric acid supply
disruptions in the past. Concerns are
primarily due to increased
competition and reliance on imports
of phosphate rock and phosphoric
acid.

Strong domestic manufacturing
capabilities and a distributed
manufacturing base provide some
resilience to supply disruptions.
However, the need to obtain
manufacturing inputs on the
international market could increase
vulnerability.

Risk Rating: Moderate-Low

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References

Agency for Toxic Substances & Disease Registry (ATSDR), 2005. Toxicological Profile for Zinc, retrieved from
https://www.atsclr.cclc.gov/toxprofiles/tp60.pclf

American Water Works Association (AWWA), 2006. B506, Zinc Orthophosphate. Denver, CO: American
Water Works Association.

Carus Corporation (Carus), 2001. Fact Sheet for Virchem 511, Zinc Orthophosphate, retrieved from
https://www.waterwiseenterprises.com/Carus/Virchem%20511%20Fact%20Sheet.pdf

Carus Corporation (Carus), (n.d.). Carus Proprietary Zinc Phosphate Water Treatment Chemicals Product
Safety Summary, retrieved from https://www.carusllc.com/wp-
content/uploads/CarusZincAndOrthoPhosphate ProductSafetvSummarvcp.pdf

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/waterutilitvresponse/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/waterutilityresponse/water-sector-supplv-chain-resilience

National Center for Biotechnology Information (NCBI), 2022. PubChem Compound Summary for CID 24519,
Zinc Phosphate, retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/Zinc-Phosphate

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Zinc Orthophosphate Supply Chain - Full Profile

NSF International (NSF), 2021. Search for NSF Certified Drinking Water Treatment Chemicals, retrieved from

https://info.nsf.org/Certified/PwsChemicals/

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/current
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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