Sulfuric Acid Supply Chain - Executive Summary

Sulfuric Acid

Direct Use Chemical Precursor Chemical

h2so4

(liquid)

Inputs to Manufacturing Process:

Sulfur	Oxygen

^ Derivative Water Treatment Chemicals:

Aluminum Sulfate Ferric Sulfate
Fluorosilicic Acid Ferrous Sulfate
Phosphoric Acid Zinc Orthophosphate

% of Total Domestic Consumption
Attributed to Water Sector:

Less than 1%

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Map of Suppliers & Manufacturers

Product Family:

Sulfur

CAS No.:

7664-93-9

Shelf Life:

36 Months

— RISK OF SUPPLY DISRUPTION (Assessed in 2022)

RISK RATING: Low

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RISK DRIVERS

Competing use in fertilizers
accounts for the majority of
consumption of domestic pro-
duction. Sulfuric acid is com-
monly used across many in-
dustries. Concerns are primar-
ily due to periodic reductions
in production of raw material
(sulfur).

RISK SCORE PARAMETERS

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

Likelihood: Low. Previous significant
price increases, but no supply disrup-
tions.

Vulnerability: Low. Distributed
domestic manufacturing and supply.
While the majority of domestic manu-
facturing is used to produced fertilizer,
sulfuric acid is widely available.

MANUFACTURING PROCESS

Sulfur

Oxygen

Sulfuric Acid

input

End Use

Water T reatment Applications

•	pH adjustment

•	Ion exchange resin regeneration

•	Water treatment chemical production

Other Applications

•	Fertilizer (primarily phosphoric acid production)

•	Chemical manufacturing

•	Ore leaching

•	Petroleum refining

DOMESTIC PRODUCTION AND CONSUMPTION, AND INTERNATIONAL TRADE

Domestic Manufacturing Locations (2015):

98, distributed throughout the U.S.

(^) International Trade (2019)

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

Domestic Consumption (2019):
25,596 M kg

¦	Domestic Production (22,845 M kg)

¦	Imports for Consumption (2,970 M kg)

¦	Export of Domestic Production (220 M kg)

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Sulfuric Acid Supply Chain - Full Profile

Product Description

Sulfuric acid (H2S04) is an inorganic, strong acid that is widely used for pH adjustment. It is one of the most
widely produced chemicals in the world, and is a key input in the production of phosphoric acid. The primary
manufacturing process in the U.S. is requires elemental sulfur. The majority of sulfuric acid manufactured in the
U.S. is used in fertilizer formulations.

Use in Water Treatment

Sulfuric acid widely is used in water treatment for pH adjustment, and can also be used to regenerate ion
exchange resin.

Use as a Precursor to Other Water Treatment Chemicals

Sulfuric acid is used to manufacture aluminum sulfate, ferrous and ferric sulfate, fluorosilicic acid, phosphoric
acid, and zinc orthophosphate.

Other Applications

Sulfuric acid has a wide range of applications, and is used directly or indirectly in many industries. The largest
single use of sulfuric acid is for the production of phosphoric acid for use in fertilizer. Other uses include
industrial chemical manufacturing, extraction of metals from ores, oil refining, pickling and descaling steel,
battery acid, wood pulping, and detergent manufacturing (ATSDR, 1998; The Mosaic Company, 2021; The
Sulphur Institute, 2018).

Primary Industrial Consumers

The use of sulfuric acid for phosphate fertilizer manufacturing accounts for the majority of domestic
consumption, historically estimated to range between 60-75% of domestic sulfuric acid consumption. Other
significant uses are industrial and agricultural chemical manufacturing, ore leaching, and petroleum refining
accounting for a combined 35% (McCoy, 2008; NCBI, 2022). Direct use in water treatment is a small percent
(< 1%) of the domestic market.

Manufacturing, Transport, & Storage

Manufacturing Process

A significant quantity of sulfuric acid produced in the U.S. starts with molten sulfur or less commonly prilled
(pelletized) sulfur. Other production methods include acid regeneration and smelter gas recovery.

The most common sulfuric acid manufacturing process proceeds in several steps, outlined in Figure 1. Molten
sulfur is oxidized in the presence of dry air (often an oxygen-enriched air) to produce sulfur dioxide, which is
cooled for introduction to the converter system. In the presence of a catalyst, sulfur dioxide is converted to
sulfur trioxide, and the process gas is moved to an absorption step where sulfur trioxide is absorbed in sulfuric
acid to form oleum (sulfur trioxide in sulfuric acid). The oleum, which is much more soluble in water than sulfur
trioxide, is cooled and reacted with water to produce concentrated sulfuric acid.

EPA 817-F-22-052 | December 2022

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Sulfuric Acid Supply Chain - Full Profile

Step 1

Sulfur + Oxygen —> Sulfur Dioxide

S + O2 —^	SO2

Step 2

Sulfur Dioxide + Oxygen —> Sulfur Trioxide

2S02	+ 02 -> 2S03

Step 3

Sulfur Trioxide + Sulfuric Acid —> Oleum

SO3	+ H2SO4	—^ H2S2O7

Step 4

Oleum + Water —> Sulfuric Acid
H2S2O7 + H20 -> 2H2SO4

Figure 1. Chemical Equation for the Reaction to Manufacture Sulfuric Acid

Sulfuric acid can also be produced as a byproduct of smelting mineral ores containing sulfur. Roasting of metal
sulfides to obtain the metal releases sulfur in the form of sulfur dioxide. Further metal processing, including
leaching, requires sulfuric acid, which can be produced from the sulfur dioxide (The Sulphur Institute, 2018).
Spent sulfuric acid may be reclaimed from petroleum refining, steel pickling, and chemical processing and
further processed for resale (USGS, 2022).

Product Transport

Sulfuric acid is typically sold as a liquid in a range of concentrations, in bulk quantities and primarily delivered by
specialized railcars to suppliers who repackage and sell the product directly to customers. Transport of sulfuric
acid must adhere to the appropriate methods and regulations related to its status as a highly corrosive
substance. Sulfuric acid produced by regeneration plants and smelting often requires transport to
manufacturing or refining sites (The Sulphur Institute, 2018).

Storage and Shelf Life

Sulfuric acid should be stored in corrosion-resistant vessels in a cool place away from direct sunlight. When
stored properly, sulfuric acid can have a shelf life of 36 months, depending on concentration and size of storage
container (CORECFIEM, 2021; The Sulphur Institute, 2018).

Domestic Production & Consumption
Domestic Production

Production data was collected from the EPA Toxic Substances Control Act (TSCA) Chemical Data Reporting (CDR),
while trade data was collected from the U.S. International Trade Commission (USITC) Dataweb, as characterized
in Table 1. Both production and trade data are specific to sulfuric acid.

Table 1. Sulfuric acid Production and Trade Data Sources

Production and Trade Data

Category

Data Source

Identifier

Description

Domestic Production

2020 TSCA Chemical Data Reporting

CAS No.: 7664-93-9

Sulfuric Acid

Imports and Exports

U.S. International Trade Commission

HS Code: 2807.00

Sulfuric Acid

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Sulfuric Acid Supply Chain - Full Profile

Total U.S. domestic manufacturing of sulfuric acid was approximately 22,845 million kilograms (M kg) in 2019
(EPA, 2020). The majority of domestic commercial manufacture of sulfuric acid takes place at phosphate rock
processing facilities located throughout the contiguous U.S. (The Mosaic Company, 2021; Potash, 2015). Many of
these facilities are owned by a relatively small number of companies including the Mosaic Company (Mosaic)
and PCS Phosphate fEPA, 2020). Mosaic reported production of approximately 10,000 M kg of sulfuric acid in
2019, and the majority was reported used on-site for production of phosphoric acid. Mosaic purchased the
majority of sulfur used to produce the sulfuric acid from North American oil and natural gas refiners (The Mosaic
Company, 2021). Domestic manufacturing of sulfuric acid is widely distributed throughout the U.S. The number
of domestic manufacturing locations shown in Figure 2 represents operating facilities as of 2015. Supply of
NSF/ANSI Standard 60 certified sulfuric acid for use in drinking water treatment is also 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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Sulfuric Acid Supply Chain - Full Profile

Domestic Consumption

U.S. consumption of sulfuric acid in 2019 is estimated at 25,596 M kg. This includes production of 22,845 M kg,
import of 2,970 M kg, minus export of 220 M kg (EPA, 2020; USITC, 2021), as shown in Figure 3.

• Domestic Consumption (2019):

25,596 M kg

I ¦ Domestic Production (22,845 M kg)

L ¦ Imports for Consumption (2,970 M kg)

¦ Export of Domestic Production (220 M kg)

Figure 3. Domestic Production and Consumption of Sulfuric Acid in 2019

Trade & Tariffs

Worldwide Trade

Worldwide import and export data for sulfuric acid are reported through the World Bank's World Integrated
Trade Solutions (WITS) software, as a category specific to sulfuric acid. In 2021, U.S. ranked 12th worldwide in
total exports and first in total imports of sulfuric acid. In 2021, China ranked first worldwide in total exports
(WITS, 2022), as shown in Table 2.

Table 2. WITS Worldwide Export and Import of Sulfuric Acid in 2021

2021 Worldwide Trade
Sulfuric Acid (HS Code 2807.00)

Top 5 Worldwide Exporters

Top 5 Worldwide Importers

China

3,000 M kg

United States

3,252 M kg

Canada

1,904 M kg

Chile

2,451 M kg

Germany

1,136 M kg

Morocco

2,109 M kg

Peru

1,110 M kg

India

1,874 M kg

Mexico

970 M kg

Philippines

1,522 M kg

Domestic Imports and Exports

Domestic import and export data are reported by USITC in categories specific to sulfuric acid. Figure 4
summarizes imports for consumption1 and domestic exports2 of sulfuric acid between 2015 and 2020. During
this period, the overall quantity of imports and exports remained relatively steady, with imports for
consumption exceeding domestic exports. Over this five-year period, Canada was the primary recipient of
domestic exports and the primary source of imports (USITC, 2021).

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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Sulfuric Acid Supply Chain - Full Profile

Domestic Trade of Sulfuric Acid

4'000	HTS Code 2807.00

3,600
3,200
2,800

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Imports
Exports

Imports
Exports

Imports
Exports

Imports
Exports

Imports
Exports

Imports
Exports

2015 2016

2017

2018

2019 2020

¦	Imports from Canada	¦ Exports to Canada

¦	Imports from Mexico	¦ Exports to Mexico

¦	Imports from Other Countries	Exports to Other Countries

Figure 4. USITC Domestic Import and Export of Sulfuric Acid between 2015 and 2020

Tariffs

There is no general duty for import of sulfuric acid, however there is an additional 25% duty on imports from
China (USITC, 2022), as summarized in Table 3.

Table 3. Domestic Tariff Schedule for Sulfuric Acid in 2020

HS Code

General Duty

Additional Duty - China
(Section 301 Tariff List)

Special Duty

2807.00

None

25%

None

Market History & Risk Evaluation

History of Shortages

The U.S. is one of the leading worldwide producers of sulfuric acid, and there were no identified significant
supply chain disruptions between 2000 and 2022. However, there is a history of price volatility. The majority of
elemental sulfur, the primary input in sulfuric acid manufacturing, is recovered as a byproduct of natural gas and
petroleum processing. As described in the history of shortages for the sulfur supply chain profile (EPA, 2022b),
the price and availability of sulfur is closely tied to demand for fuels and petroleum products (USGS, 2022).

While the majority of recovered elemental sulfur is directed to manufacturing of sulfuric acid, demand for
sulfuric acid, is tied to demand for fertilizer. Between 2020 and 2022, theses drivers have led to price
fluctuations for sulfuric acid.

Risk Evaluation

The complete risk assessment methodology is described in Understanding Water Treatment Chemical Supply
Chains and the Risk of Disruptions (EPA, 2022c). The risk rating is calculated as the product of the following three
risk parameters:

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Sulfuric Acid Supply Chain - Full Profile

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.

Table 4. Supply Chain Risk Evaluation for Sulfuric Acid

Risk Parameter Ratings and Drivers





1

1 Criticality High

1 Likelihood Low 1

1 Vulnerability Low 1

Sulfuric acid is essential to the water
sector and has widespread application
for pH adjustment. It is a precursor in
the production of numerous critical
water treatment chemicals.

The water sector did not experience
sulfuric acid supply chain
disruptions between 2000 and
2022. However, the water sector
has experienced significant
increases in price in the past.
Concerns are primarily due to
periodic reductions in production of

Strong domestic manufacturing
provides some resilience to supply
disruptions. While the majority of
domestic manufacturing is used to
produce fertilizer, sulfuric acid is
widely available.

Risk Rating: Low

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References

Agency for Toxic Substances and Disease Registry (ATSDR), 1998. Toxicological profile for Sulfur, Sulfur
Trloxlde, and Sulfuric Acid, retrieved from

https://wwwn.cdc.gov/TSP/ToxProfiles/ToxProfiles.aspx?id=253&tid=46
CORECHEM, 2021. Sulfuric Acid Safety Data Sheet, retrieved from https://corecheminc.com/wp-

content/uploads/2021/06/Sulfuric-Acid-93-98-Solution-CQRECHEM-lnc.-Safetv-Data-Sheet-2021.06.17-
Revision-4.pdf

EPA, 2016. 2016 TSCA Chemical Data Reporting, retrieved from https://www.epa.gov/chemical-data-
reporting/access-cdr-data#2016

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Sulfuric Acid Supply Chain - Full Profile

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. Sulfur Supply Chain - Full Profile, retrieved from

https://www.epa.gov/waterutilityresponse/water-treatment-chemical-supplv-chain-profiles

EPA, 2022c. Understanding Water Treatment Chemical Supply Chains and the Risk of Disruptions, retrieved
from https://www.epa.gov/waterutilityresponse/risk-disruptions-supplv-water-treatment-chemicals

McCoy, M., 2008. The Acid Touch: Rising prices for sulfuric acid have widespread industrial impact, Chemical
& Engineering News, April 14, 2008, retrieved from https://cen.acs.org/articles/86/il5/Acid-
Touch.html&cd=l&hl=en&ct=clnk&gl=us

National Center for Biotechnology Information (NCBI), 2022. PubChem Compound Summary for CID 1118,
Sulfuric Acid, retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/1118

NSF International, 2021. Search for NSF Certified Drinking Water Treatment Chemicals, retrieved from
https://info.nsf.org/Certified/PwsChemicals/

Potash Corporation of Saskatchewan, Inc. (Potash), 2015. Form 10-K2014, retrieved from

https://www.sec.gov/Archives/edgar/data/855931/000119312515062Q91/d863198dl0k.htm

The Mosaic Company, 2021. Form 10-K 2020, retrieved from https://investors.mosaicco.com/financials/sec-
filings/default.aspx

The Sulphur Institute, 2018. Evaluation of Loading and Unloading Operations for Sulphuric Acid and Spent
Sulphuric Acid Rail Tank Cars, September 1, 2018, retrieved from
https://www.sulphurinstitute.org/pub/?id=478a5ef2-c710-c5b3-ec9e-62947fac411e

U.S. Geological Survey (USGS), 2022. 2018 Minerals Yearbook: Sulfur, retrieved from
https://pubs.usgs.gov/mvb/voll/2018/mybl-2018-sulfur.pdf

U.S. International Trade Commission (USITC), 2021. USITC DataWeb, retrieved from
https://dataweb.usitc.gov/

U.S. International Trade Commission (USITC), 2022. 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-byhs6product.aspx?lang=en#void

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