U.S. imports of Phosphinates (Hypophosphites) and Phosphonates (Phosphites) (SITC 52361) totaled $4.0M in August 2026, imported from 11 countries.
Importers of Phosphinates (Hypophosphites) and Phosphonates (Phosphites) paid $1.5M in duties in August 2026, an average duty rate of 37.81% — duty actually collected as a share of the imports that cleared customs, not the published tariff schedule. Phosphinates (Hypophosphites) and Phosphonates (Phosphites) imports of $4.0M in August 2026 ran 118% above the year-to-date monthly average of $1.8M.
Last updated: August 2026 dataPhosphinates and phosphonates — the lower oxidation-state relatives of phosphates — are specialty inorganic chemicals used as reducing agents, antioxidants in polymer stabilization, and intermediates in agrochemical and pharmaceutical synthesis. The distinction between hypophosphites (phosphinates) and phosphites (phosphonates) is chemically precise and directly determines the correct tariff line, so laboratory certification of oxidation state is a practical necessity for customs documentation. Supply chains for these compounds are concentrated in Asia, and importers should monitor whether specific products or origins are subject to Section 301 measures.
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26 import shipments a month
Hypophosphites (phosphinates, P in +1 oxidation state) and phosphites (phosphonates, P in +3 oxidation state) are chemically and commercially distinct from phosphates (P in +5 state). Each maps to a different tariff provision, so a certificate of analysis confirming the phosphorus oxidation state is essential to avoid misclassification and potential penalties.
Sodium hypophosphite is widely used in electroless nickel plating and as a reducing agent in chemical synthesis. Phosphonates serve as scale and corrosion inhibitors in water treatment, as flame retardants in polymers, and as building blocks for herbicides such as glyphosate. The end-use sector should be documented to support correct classification and any applicable end-use certificate requirements.
Basic heading 329 of 465 in section 5
Basic heading 52361 · $4.0M of $27.5B
Imports · August 2026
origin
China and Switzerland together supply 98% of it. China pays 39.2% duty; Denmark 10.0%.
customs district
Census does not publish district detail for this classification system.
destination
Census does not publish state detail for this classification system.
entry
Census does not publish port detail for this classification system.
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ImportsExports
Imports
$4.0MYoY · free account
Exports
$322KYoY · free account
12-mo low · imports
Low · free accountOver the twelve months to August 2026, the U.S. imported $22.0M of Phosphinates (Hypophosphites) and Phosphonates (Phosphites) and exported $2.1M.
Through August 2026. Source: U.S. Census Bureau.