Sodium Chlorite Supply Chain - Executive Summary
Sodium Chlorite
Direct Use Chemical
NaCI02
(liquid or solid)
Inputs to Manufacturing Process: % of Total Domestic Consumption
Hydrogen Peroxide Sodium Hydroxide Attributed to Water Sector:
Sodium Chlorate Less t'13" 10%
J* Derivative Water Treatment Chemicals:
*
None
dab Understanding Chemical Supply Chains
Map of Suppliers & Manufacturers
A. Product Family:
Chlor-alkali
CAS No.:
7758-19-2
2 Shelf Life:
12 Months
— RISK OF SUPPLY DISRUPTION (Assessed in 2022)
RISK RATING: Low
Ae{a*e"LOW Mode'a%vV,
RISK DRIVERS
Domestic manufacturing of sodium
chlorite is limited, and supply to
meet demand is believed to be
import-dependent. Supply of two
key inputs pose potential risks.
Supply of sodium hydroxide, a
chlor-alkali co-product, has experi-
enced previous disruptions, while
supply of sodium chlorate is
import-dependent.
RISK PARAMETERS
Criticality: Moderate-High. Essential
for chlorine dioxide generation.
Likelihood: Low. No disruptions in
supply that impacted the water sec-
tor between 2000 and 2022.
Vulnerability: Moderate-High. Lim-
ited domestic manufacturing and
reliance on imports to meet de-
mand.
MANUFACTURING PROCESS
Water Treatment Applications
[
Sodium Chlorate
]
Sodium Hydroxide ¦
Hydrogen Peroxide
Sodium Chlorite
[
Input
End Use
• Disinfection
• On-site generation of chlorine dioxide
Other Applications
• General disinfection
• Bleaching
• Pesticides, fungicides, algicides
DOMESTIC PRODUCTION AND CONSUMPTION, AND INTERNATIONAL TRADE
Domestic Manufacturing Locations (2015):
3, in Utah, Nebraska, and Illinois
(^) International Trade (2019)
PrimaryTrading Partner (Imports): Canada
PrimaryTrading Partner (Exports): Canada
Domestic Consumption (2019):
103 M kg
Domestic Production (0.02 M kg)
¦ Imports for Consumption (138 M kg)
I Export of Domestic Production (35 M kg)
&EPA
-------
Sodium Chlorite Supply Chain - Full Profile
Product Description
Sodium chlorite (NaCI02), an inorganic chemical and strong oxidant, is widely used for on-site generation of the
disinfectant chlorine dioxide, which is generated on-site due to rapid decomposition. Sodium chlorite is also
widely used for hydrogen sulfide odor control. The majority of sodium chlorite manufactured in the U.S. is used
in cleaning and general disinfection applications.
Use in Water Treatment
Sodium chlorite is used in the on-site generation of chlorine dioxide. Chlorine dioxide is produced by activating
sodium chlorite with an oxidizing agent or acid, which in turn is used as an oxidant and disinfectant. It is also
used to control hydrogen sulfide odors in wastewater treatment (AWWA, 2018).
Use as a Precursor to Other Water Treatment Chemicals
Sodium chlorite is not used to manufacture other water treatment chemicals.
Other Applications
Sodium chlorite is most commonly used in the activated form as chlorine dioxide. Applications of activated
sodium chlorite include water treatment, food manufacturing, oil and gas (sulfide-reducing bacteria control),
and in the formulation of herbicides, pesticides, fungicides, and algaecide (ATSDR, 2004; NCBI, 2021).
Primary Industrial Consumers
The majority of sodium chlorite applications rely on the activated form, chlorine dioxide. While wood-pulp
bleaching is the largest single use of chlorine dioxide, large scale applications of chlorine dioxide that do not
require a high-purity product generally use sodium chlorate as a starting material. Chlorine dioxide disinfection
applications requiring a highly-purified product, including water treatment and food production, are the primary
domestic applications of sodium chlorite. Water treatment is estimated as less than 10% of overall sodium
chlorite consumption (ATSDR, 2004).
Manufacturing, Transport, & Storage
Manufacturing Process
Sodium chlorate, hydrogen peroxide, and sodium hydroxide are the most common starting materials used to
produce sodium chlorite. The reaction, illustrated by the equation shown in Figure 1, proceeds from the
reduction of chlorine dioxide gas (generated from sodium chlorate) in an alkaline solution (most commonly
sodium hydroxide) with hydrogen peroxide (OxyChem, 2015; OxyChem, 2018a).
Chlorine Dioxide + Hydrogen Peroxide +
Sodium Hydroxide —»
Sodium Chlorite + Water
+ Oxygen
(from Sodium Chlorate)
2CI02 + H2O2 +
2NaOH ->
2NaCI02 + 2H20
+
o
N)
Figure 1. Chemical Equation for the Reaction to Manufacture Sodium Chlorite
Product Transport
Sodium chlorite is transported in bulk by truck, rail, barge, and ship as a hazardous material (OxyChem, 2018b).
Storage and Shelf Life
Sodium chlorite, commonly sold as a solid or solution, should be stored in a tightly closed container and kept in
a cool place away from the direct sunlight. When stored properly, sodium chlorite can have a shelf life of
EPA 817-F-22-045 | December 2022
f/EPA
-------
Sodium Chlorite Supply Chain - Full Profile
approximately 12 months, depending on storage conditions (OxyChem, 2018b).
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 sodium chlorite, trade data includes sodium
chlorite as part of the category for hypochlorites, chlorites, and hypobromites.
Table 1. Sodium Chlorite 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.: 7758-19-2
Sodium Chlorite
Imports and Exports
U.S. International Trade Commission
HS Code: 2828.90
Hypochlorites, Chlorites, and
Hypobromites
Total U.S. domestic manufacturing of sodium chlorite reported under the CDR was approximately 0.02 million
kilograms (M kg) in 2019; however, several leading manufacturers (e.g., OxyChem) claimed confidential business
information and did not report production volumes to EPA (EPA, 2020). Domestic commercial manufacture of
sodium chlorite takes place at only a few identified domestic facilities located in Utah, Nebraska, and Illinois.
Most sodium chlorite production facilities rely on the availability of sodium chlorate and sodium hydroxide. 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 sodium chlorite 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 Locator Tool (EPA,
2022a).
2
f/EPA
-------
Sodium Chlorite Supply Chain - hull Profile
O
O
O
O
- O
#
o
a
• J " ^ °
o
o
o
o
o
o
o
¦o
' *4 f ¦
Domestic Supply and Manufacturing of Sodium Chlorite
O 24 NSF/ANSI Standard 60 Certified Suppliers (NSF International, 2021)
9 3 Domestic Manufacturing Locations (EPA Chemical Data Reporting, 2016)
Figure 2. Domestic Supply and Manufacturing of Sodium Chlorite
Domestic Consumption
U.S. consumption of sodium chlorite in 2019 is an estimate based on production of sodium chlorite and trade of
a broader category of hypochlorites, chlorites, and hypobromites. Trade of sodium chlorite is believed to be a
small percentage of import and export volume in this category. This estimate includes production of 0.02 M kg,
import of 138 M kg, minus export of 35 M kg (EPA, 2020; USITC, 2021), as shown in Figure 3.
Domestic Consumption (2019):
103 M kg
Domestic Production (0.02 M kg)
¦ Imports for Consumption (138 M kg)
¦ Export of Domestic Production (35 M kg)
Figure 3. Domestic Production and Consumption of Sodium Chlorite in 2019
Trade & Tariffs
Worldwide Trade
Worldwide import and export data for sodium chlorite are reported through the World Bank's World Integrated
3
SEPA
-------
Sodium Chlorite Supply Chain - Full Profile
Trade Solutions (WITS), as a category representing a class of compounds including hypochlorites, chlorites, and
hypobromites. In 2021, the U.S. ranked eighth worldwide in total exports and first in total imports of
hypochlorites, chlorites, and hypobromites. In 2021, China ranked first worldwide in total exports (WITS, 2022),
as shown in Table 2. Import and export data specific to sodium chlorite is unavailable from the referenced
sources.
Table 2. WITS Worldwide Export and Import of Hypochlorites, Chlorites, and Hypobromites in 2021
2021 Worldwide Trade
Hypochlorites, Chlorites, and Hypobromites (HS Code 2828.90)
Top 5 Worldwide Exporters
Top 5 Worldwide Importers
China
156 M kg
United States
133 M kg
Canada
131 M kg
France
74 M kg
Belgium
87 M kg
Canada
56 M kg
Spain
83 M kg
Germany
54 M kg
Germany
72 M kg
Italy
47 M kg
Domestic Imports and Exports
Domestic imports and export data are reported by USITC in a category including hypochlorites, chlorites, and
hypobromites. Figure 4 summarizes imports for consumption1 and domestic exports2 of hypochlorites, chlorites,
and hypobromites between 2015 and 2020. During this period, the overall quantity of exports and imports
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).
Domestic Trade of Hypochlorites, Chlorites, and Hypobromites
160 HTS Code 2828.90
140
120
100
80
_ 60
OD
-V
40
c
o
= 20
IS) MM V) V) V) V) V) V) V)
O o oo oo oo oo oo
Q.Q. Q.Q. Q.Q. Q.Q. Q. Q. Q. Q_
EX ex c x cx ex ex
UJ — uj w oj _ uj _ uj & qj
2015 2016 2017 2018 2019 2020
¦ Imports from Canada ¦ Exports to Canada
¦ Imports from China ¦ Exports to Mexico
¦ Imports from Other Countries Exports to Other Countries
Figure 4. USITC Domestic Import and Export of Hypochlorites, Chlorites, and Hypobromites 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.
4
f/EPA
-------
Sodium Chlorite Supply Chain - Full Profile
Tariffs
There is a 3.7% general duty for import of sodium chlorite and an additional 25% duty on imports from China
(USITC, 2022), as summarized in Table 3.
Table 3. 2022 Domestic Tariff Schedule for Hypochlorites, Chlorites, and Hypobromites
HS Code
General Duty
Additional Duty - China
(Section 301 Tariff List)
Special Duty
2828.90
3.7%
25%
Free (A, AU, BH, CA, CL, CO, D, E, IL, JO, KR,
MA, MX, OM, P, PA, PE, SG)3
Market History & Risk Evaluation
History of Shortages
There were no identified sodium chlorite supply chain disruptions impacting the water sector between 2000 and
2022. However, there are specific potential vulnerabilities to the production of sodium chlorite. Domestic
production takes place at very few manufacturing locations, and reliance on imports to meet domestic
consumption is believed to be significant. Additionally, two key inputs to the production of sodium chlorite,
sodium chlorate and sodium hydroxide, are dependent on the chlor-alkali industry. Sodium hydroxide, a primary
chlor-alkali co-product has historically been subject to uneven supply and demand patterns and supply
disruptions.
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
5
f/EPA
-------
Sodium Chlorite Supply Chain - Full Profile
Table 4. Supply Chain Risk Evaluation for Sodium Chlorite
Risk Parameter Ratings and Drivers
1
1
1 Criticality Moderate-High
1 Likelihood Low 1
Vulnerability Moderate-High 1
Sodium chlorite is essential to the
water sector for onsite generation of
chlorine dioxide and odor control in
wastewater treatment. However,
chlorine dioxide is not as widely used
as other oxidants.
The water sector did not experience
any sodium chlorite supply
disruptions between 2000 and 2022.
Limited domestic manufacturing
capabilities and a significant reliance
on imports to meet domestic demand
could increase vulnerability.
Risk Rating: Low
te-Low M°<*er
Voge RanSe e/>
~ ^
IP
0>
i (jo
References
Agency for Toxic Substances and Disease Registry (ATSDR), 2004. Toxicological Profile for Chlorine Dioxide
and Chlorite, retrieved from https://www.atsdr.cdc.gov/toxprofiles/tpl60.pdf
American Water Works Association (AWWA), 2018. B303, Sodium Chlorite. Denver, CO: American Water
Works Association.
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/waterutilitvresponse/risk-disruptions-supplv-water-treatment-chemicals
National Center for Biotechnology Information (NCBI), 2021. PubChem Compound Summary for CID
23668197, Sodium Chlorite, retrieved from https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-
chlorite
NSF International, 2021. Search for NSF Certified Drinking Water Treatment Chemicals, retrieved from
https://info.nsf.org/Certified/PwsChemicals/
OxyChem, 2015. Sodium Chlorite Handbook, retrieved from https://www.oxv.com/operations/essential-
chemistry/other-essentials/
OxyChem, 2018a. Sodium Chlorite Treatment of Drinking Water with Chlorine Dioxide, retrieved from
https://www.oxv.com/operations/essential-chemistrv/other-essentials/
OxyChem, 2018b. Sodium Chlorite Technical (EPA Registered) for Chlorine Dioxide Generation, retrieved from
6
f/EPA
-------
Sodium Chlorite Supply Chain - Full Profile
https://www.oxy.com/operations/essential-chemistrv/other-essentials/
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/
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
7
f/EPA
------- |