Sodium Hydroxide Supply Chain - Executive Summary

Sodium Hydroxide

Direct Use Chemical Precursor Chemical

NaOH

(liquid)

Inputs to Manufacturing Process:

Sodium Chloride

Derivative Water Treatment Chemicals:
Aluminum Hydroxide Monosodium Phosphate
Calcium Hypochlorite Disodium Phosphate
Sodium Hypochlorite Sodium Silicate
Sodium Chlorite

% of Total Domestic Consumption
Attributed to Water Sector:
Approximately 3%

(^Understanding Chemical Supply Chains
Map of Suppliers & Manufacturers

w Product Family:
Chlor-alkali

CAS No.:
1310-73-2

2 Shelf Life:
24 Months

— RISK OF SUPPLY DISRUPTION (Assessed in 2022)

RISK RATING: Moderate-High

Low Moderat

RISK DRIVERS

Sodium hydroxide is co-produced
with chlorine through the chlor-
alkali process, and demand for
chlorine generally drives chlor-
alkali production output. This can
create an uneven supply of sodi-
um hydroxide. Furthermore, un-
planned and planned chlor-alkali
production outages have result-
ed in supply disruptions.

RISK PARAMETERS

Criticality: High. Essential for pH
adjustment and production of water treat-
ment chemicals.

Likelihood: High. Previous local disrup-
tions in supply that impacted the water
sector.

Vulnerability: Low. Distributed domestic
manufacturing and supply. Loss of produc-
tion capacity could increase vulnerability.

MANUFACTURING PROCESS

Sodium Chloride

Sodium Hydroxide

Input

End Use

Water Treatment Uses

•	pH adjustment

•	Precipitation of metals

Water treatment chemical production
Competing Uses	

•	Inorganic and organic chemicals

•	Pulp and paper

•	Alumina production

•	Neutralizing agent

DOMESTIC PRODUCTION AND CONSUMPTION, AND INTERNATIONAL TRADE

Domestic Manufacturing Locations (2019):
41, distributed throughout the U.S.

(^) International Trade (2019)

PrimaryTrading Partner (Imports): Taiwan
PrimaryTrading Partner (Exports): Brazil

Domestic Consumption (2019):
6,046 Million kg

¦	Domestic Production (11,627 M kg)

¦	Imports for Consumption (792 M kg)

¦	Export of Domestic Production (6,373 M kg)

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Sodium Hydroxide Supply Chain - Full Profile

Product Description

Sodium hydroxide (NaOH) is an inorganic, strong base that is widely used for pH adjustment. It is a foundational
product of the chlor-alkali industry, primarily manufactured through electrolysis of a sodium chloride brine. The
majority of sodium hydroxide manufactured in the U.S. is used in organic and inorganic chemical production.

Use in Water Treatment

Sodium hydroxide is used in water treatment for pH adjustment and precipitation of metals (AWWA, 2019;
NCBI, 2020).

Use as a Precursor to Other Water Treatment Chemicals

Sodium hydroxide is used to manufacture aluminum hydroxide, calcium hypochlorite, sodium hypochlorite,
sodium chlorite, mono- and disodium phosphate, and sodium silicate.

Other Applications

Sodium hydroxide has a wide range of applications. The leading uses of sodium hydroxide in North America are
inorganic and organic chemical manufacturing, and pulp and paper manufacturing. Other applications include
manufacturing of soap, bleach, plastics, pharmaceuticals, and alumina production. Sodium hydroxide is also
used as a neutralizing agent in many industrial applications, including the manufacturing of synthetic materials
(NCBI, 2020; IHS Markit, 2017; Westlake Corporation, 2018).

Primary Industrial Consumers

In 2015, the use of sodium hydroxide for organic chemical synthesis accounted for 23% of North American
consumption, followed by pulp and paper manufacturing and inorganic chemical production, which each
accounted for 22% of North American consumption. A variety of specialty applications including alumina
production accounted for the remaining 33%. All water treatment applications, including wastewater treatment
and drinking water treatment, account for 3% of North American consumption (IHS Markit, 2017).

Manufacturing, Transport, & Storage

Manufacturing Process

Sodium chloride is the primary raw material used to produce sodium hydroxide. The majority of sodium
hydroxide is produced using the chlor-alkali process, which involves passing a direct electric current through a
sodium chloride brine (i.e., electrolysis), converting chloride ions to elemental chlorine at the anode while
sodium ions and hydrogen gas collect at the cathode to react and form sodium hydroxide (The Chlorine
Institute, 2014). The general equation for this process is shown in Figure 1. Sodium hydroxide is separated from
the solution using one of the following three methods: (1) the diaphragm method; (2) the membrane method;
or (3) the mercury cell method. The diaphragm method is the most common separation process used in North
America (The Chlorine Institute, 2014; Westlake Corporation, 2018).

Sodium Chloride Brine

-> Chlorine Gas

+ Hydrogen Gas + Sodium Hydroxide

2NaCI + 2H20

-> Cl2

+ H2 + 2NaOH





; 4,



Anode

Cathode Cathode

Figure 1. Chemical Equation for the Reaction to Manufacture Sodium Hydroxide

EPA 817-F-22-046 | December 2022

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Sodium Hydroxide Supply Chain - Full Profile

Sodium hydroxide can also be produced from trona; the primary, natural source of sodium carbonate in North
America. Sodium hydroxide manufactured from trona is formed when sodium carbonate is combined with a
lime (calcium hydroxide) solution in a precipitation reaction forming a sodium hydroxide solution and calcium
carbonate precipitate (Eldoma et al., 2013; Genesis Alkali, 2017).

Product Transport

Sodium hydroxide can be transported in bulk or smaller containers by truck, rail, barge, and ship (Westlake
Corporation, 2018).

Storage and Shelf Life

Sodium hydroxide is highly reactive and corrosive, and thus should be stored in non-reactive storage vessels at
room temperature in a dry, cool place to avoid solidification. When stored properly, sodium hydroxide in
solution can have a shelf life of 24 months, depending on concentration and size of storage container
(CORECHEM, 2017; Puritan Products, 2017).

Domestic Production & Consumption

Domestic Production

Production data was collected from the Chlorine Institute, while trade data was collected from the U.S.
International Trade Commission (USITC) Dataweb, as characterized in Table 1. Both production data and trade
data are specific to sodium hydroxide in an aqueous solution.

Table 1. Sodium Hydroxide Production and Trade Data Sources

Production and Trade Data

Category

Data Source

Identifier

Description

Domestic Production

The Chlorine Institute

CAS No.: 1310-73-2

Sodium Hydroxide (Aqueous)

Imports and Exports

U.S. International Trade Commission

HS Code: 2815.12

Sodium Hydroxide (Aqueous)

Total U.S. domestic manufacturing of sodium hydroxide was approximately 11,627 million kg (M kg) in 2019
(The Chlorine Institute, 2020). The majority of domestic commercial manufacture of sodium hydroxide takes
place at chlor-alkali facilities located throughout the contiguous U.S. Many of these facilities are owned by a
relatively small number of companies including Olin Corporation, Formosa Plastics Group, Westlake Corporation,
and Oxy Chemical Corporation (The Chlorine Institute, 2020). Westlake Corporation and Formosa Plastics Group
are leading global and domestic manufacturers of sodium hydroxide. While Westlake Corporation and Formosa
Plastics Group manufacture and distribute millions of tons of sodium hydroxide each year, a significant
percentage of the sodium hydroxide manufactured serves as feedstock for the derivative products these
companies produce (Formosa Plastics Group, 2021; Westlake Corporation, 2018). The number of domestic
manufacturing locations shown in Figure 2 represents operating facilities as of 2019. Supply of NSF/ANSI
Standard 60 certified sodium hydroxide 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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Sodium Hydroxide Supply Chain - hull Profile

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^ 41 Domestic Manufacturing Locations (The Chlorine Institute, 2020)

Figure 2. Domestic Supply and Manufacturing of Sodium Hydroxide



Domestic Consumption

U.S. consumption of sodium hydroxide in 2019 is estimated at 6,046 M kg. This includes production of 11,627 M
kg, import of 792 M kg, minus export of 6,373 M kg (The Chlorine Institute, 2020; IJSITC, 2021), as shown in

Figure 3.

Domestic Consumption (2019):
6,046 Million kg

¦	Domestic Production (11,627 M kg)

¦	Imports for Consumption (792 M kg)

¦	Export of Domestic Production (6,373 M kg)

Figure 3. Domestic Production and Consumption of Aqueous Sodium Hydroxide in 2019

Trade & Tariffs

Worldwide Trade

Worldwide import and export data for sodium hydroxide are reported through the World Bank's World
Integrated Trade Solutions (WITS) software, as a category specific to sodium hydroxide (aqueous solution). In
2021, U.S. ranked first worldwide in total exports and second in total imports of sodium hydroxide. In 2021,

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Sodium Hydroxide Supply Chain - Full Profile

Netherlands ranked first worldwide in total imports (WITS, 2022), as shown in Table 2. The quantity of sodium
hydroxide imported by Brazil, a country which imports significant quantities of sodium hydroxide from the U.S.,
was not reported through WITS in 2021.

Table 2. WITS Worldwide Export and Import of Sodium Hydroxide in 2019

2021 Worldwide Trade
Sodium Hydroxide (Aqueous Solution) (HS Code 2815.12)

Top 5 Worldwide Exporters

Top 5 Worldwide Importers

United States

5,749 M kg

Netherlands

1,881 M kg

Netherlands

1,980 M kg

United States

1,146 M kg

Japan

1,951 M kg

Finland

871 M kg

France

1,140 M kg

Sweden

712 M kg

China

1,094 M kg

Spain

626 M kg

Domestic Imports and Exports

Domestic import and export data are reported by USITC in categories specific to sodium hydroxide in aqueous
solution. Figure 4 summarizes imports for consumption1 and domestic exports2 of sodium hydroxide 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, Brazil was the primary
recipient of domestic exports while Taiwan was the primary source of imports (USITC, 2021). Unlike chlorine,
sodium hydroxide is easily stored and transported, which allows for greater utilization of international trade.

Domestic Trade of Sodium Flydroxide (Aqueous Solution)
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¦	Imports from Japan	¦ Exports to Australia
Imports from Other Countries Exports to Other Countries

Figure 4. USITC Domestic Import and Export of Sodium Hydroxide 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 Hydroxide Supply Chain - Full Profile

Tariffs

There is no general duty for import of sodium hydroxide, however, there is an additional 25% duty on imports
from China (USITC, 2022), as summarized in Table 3. China, one of the largest chlor-alkali producing nations, is
expected to drive future growth in chlor-alkali production (Kreuz et al., 2022).

Table 3. Domestic Tariff Schedule for Sodium Hydroxide in 2020

HS Code

General Duty

Additional Duty - China
(Section 301 Tariff List)

Special Duty

2815.12

None

25%

None

Market History & Risk Assessment

History of Shortages

Chlor-alkali producers generally set chlor-alkali production around demand for chlorine. In the past this has
created uneven supply and demand patterns for the sodium hydroxide market. When demand for chlorine
decreased during and after the Great Recession (2007-2009), a reduction in chlor-alkali production followed. The
resulting sodium hydroxide supply disruption resulted in local shortages impacting the water sector (Henderson
et al., 2009). Another shortage occurred in 2021 when Winter Storm Uri directly hit the Gulf Coast region
resulting in a temporary loss of approximately 28% of domestic chlor-alkali production capacity (The Chlorine
Institute, 2021). Furthermore, in spring and summer of 2021, a number of chlor-alkali production facilities
experienced significant equipment failures resulting in additional, temporary losses in production capacity.

While some of these impacted facilities were located in the Gulf Coast region, others were located in West
Virginia, Utah, and Washington. Later in the summer of 2021, there was a permanent reduction in chlor-alkali
production capacity at facilities located in New York, Alabama, Louisiana, and Texas. The reductions in chlor-
alkali production capacity that occurred in 2021 were compounded by the impacts of COVID-19 (Powder and
Bulk Solids, 2021; Prohaska, 2021).

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.

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Sodium Hydroxide Supply Chain - Full Profile

Table 4. Supply Chain Risk Evaluation for Sodium Hydroxide

Risk Parameter Ratings and Drivers





1

1 Criticality High

1 Likelihood

High 1

1 Vulnerability Low 1

Sodium hydroxide is essential to the
water sector and has widespread
application for pH adjustment. It is a
precursor in the production of several
other critical water treatment
chemicals.

The water sector has experienced
regional sodium hydroxide supply
disruptions in the past. Uneven supply
and demand due to the demand for
chlorine driving chlor-alkali
production, combined with unplanned
and planned chlor-alkali production
outages, have led to sodium
hydroxide supply disruptions.

Strong domestic manufacturing
capabilities and a distributed
manufacturing base provide some
resilience to supply disruptions.
However, chlor-alkali facility closures
in 2021 and the potential for future
losses in production capacity could
increase vulnerability.

Risk Rating: Moderate-High

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References

American Water Works Association (AWWA), 2019. B501 Sodium Hydroxide (Caustic Soda). Denver, CO:
American Water Works Association.

CORECHEM, 2017. Sodium Hydroxide Safety Data Sheet, retrieved from https://corecheminc.com/wp-
content/uploads/2019/03/Sodium-Hydroxide-25-Solution-CORECHEM-lnc.-Safetv-Data-Sheet-
2015.07.31.pdf

Eldoma, M.A., Almaghrabi, M.N., and S.E. Hegazi, 2013. Recovery of Sodium Hydroxide from Trona Ore and
Calcium Carbonate as Raw Materials. International Journal of Science and Research, 4(5): 2019-2924.

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
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Formosa Plastics Group, 2021. Annual Report 2020, retrieved from

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2984999587/FPG+Annual+Report+2020.pdf

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Henderson, J.L., Raucher, R.S., Weicksel, S., Oxenford, J. and Mangravite, F., 2009. Supply of critical drinking
water and wastewater treatment chemicals—A white paper for understanding recent chemical price
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IHS Markit, 2017. The Economic Benefits of Sodium Hydroxide Chemistry in Specialty Applications in the

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Sodium Hydroxide Supply Chain - Full Profile

United States and Canada, retrieved from https://www.chlorine.org/wp-
content/uploads/2017/ll/FINAL-ACC-Pulp-paper-Qct-2017.pdf

Kreuz, H., Kovics, N., Suarez, L., Lopez, A., and Herzog, N., 2022. Impact of EPA's Proposed Asbestos-
Diaphragm Chlor-Alkali Rulemaking. Chemical Market Analytics. Retrieved from
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Asbestos-Diaphragm-Chlor-Alkali-Rulemaking.pdf

National Center for Biotechnology Information (NCBI), 2020. PubChem Compound Summary for CID 14798,
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Powder and Bulk Solids, 2021. "Olin to Cut Chlor Alkali Capacity at Alabama Plant." Powder & Bulk Solids,
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capacitv-alabama-plant

Prohaska, T., 2021. "Occidental Chemical to close Niagara Falls plant; 130 jobs lost." The Buffalo News,
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niagara-falls-plant-130-iobs-lost/article ddb5463c-010a-llec-a536-9b2a8e99ba71.html

Puritan Products, 2017. Product Shelf Life/Expiration Date Policy, retrieved from

https://www.puritanproducts.com/wp-content/uploads/2016/02/Shelf-Life-Policv.pdf

The Chlorine Institute, 2014. Pamphlet 1: Chlorine Basics. The Chlorine Institute. Retrieved from
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The Chlorine Institute, 2021. U.S. Chlorine/Sodium Hydroxide Production and Shipment Report, September
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https://dataweb.usitc.gov/

U.S. International Trade Commission (USITC), 2022. Harmonized Tariff Schedule (HTS) Search, retrieved from
https://hts.usitc.gov/current

Westlake Corporation, 2018. Product Stewardship Summary: Sodium Hydroxide. Westlake Chemical

Corporation. Retrieved from https://www.westlake.com/sites/default/files/Liquid%20Caustic%20Soda-
DiaphragmMembrane-PS%20Summarv%20-%20Edl%20-%20Final Julv2018 O.pdf

World Integrated Trade Solutions (WITS), 2020. Trade Statistics by Product (HS 6-digit), retrieved from
https://wits.worldbank.org/trade/countrv-bvhs6product.aspx?lang=en#void

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