Antimony Uses: One Oxide, Three Jobs

Antimony uses are easier to follow by chemical form than by industry: one compound, the trioxide, turns up in three unrelated trades. The USGS splits American consumption differently, into metal products including flame retardants at 49%, antimonial lead and ammunition at 40%, and nonmetal products at 11%.

Where do antimony uses start?

The three headings are the Survey’s own (USGS Mineral Commodity Summaries 2026), and the first is worth pausing on. It files flame retardants under metal products, which is a taxonomy rather than a chemistry: an antimony trioxide flame retardant is an oxide powder, and the buyer who specifies it handles a powder.

Elemental antimony has almost no industrial life of its own. A pharmacology review puts it plainly: it is not commonly used for industrial purposes due to its low malleability, and it is rare due to its rapid conversion to antimony oxide or antimony trioxide. In practice it appears in alloys with copper, lead, and tin (StatPearls, Antimony Toxicity).

That is the 40% heading. Antimonial lead is a lead alloy cast into battery grids, and the USGS groups ammunition with it in the same line. The grade and price side sits on the antimony page, which covers the ingot designations and why the quoted grade is the second lowest of the four.

Extraction of the metal and purification of the oxide are separate operations, and the grades differ by the second of them. The forms that reach a factory are few enough to list.

Is antimony a flame retardant?

The 49% heading is the largest of the three, and a fire-retardant system inside it is a two-component purchase. Clariant, which sells a competing halogen-free system and therefore has an interest in the number being large, puts antimony trioxide at between 2-4% of flame-retarded plastic formulations when used as a synergist with brominated compounds (Clariant, on the substitution case).

Two consequences follow for a buyer. The first is that the decision is mostly about the brominated partner, because that partner supplies the flame chemistry and the oxide supplies the promotion of it; the factor of two that producers quote for the effect is on the grade page. The second is that a substitution programme changes both components at once. Clariant notes that phosphorus-based flame retardants are not direct drop-in replacements, with formulation adjustments often necessary.

Clariant names plastics for electronics, transportation components and building materials. The USGS, for its part, lists selected organic compounds and hydrated aluminium oxide as flame-retardant substitutes, without saying at what cost or in which polymer.

Why is antimony in PET?

The trioxide is the standard polycondensation catalyst for polyethylene terephthalate. A 2016 Polymers Communiqué article by S. Sivaram gives the working figure at 250 - 300 ppm, and adds that over 95% of world’s production of PET use antimony trioxide as the catalyst (Antimony-free Polyesters, 2016).

A catalyst is normally talked about as if it leaves no trace. This one does not entirely: residual antimony stays in the polymer, and a migration study on ovenable PET trays measured how much of it is free to move. The fraction of diffusible antimony (Sb) was estimated to be 62% in the PET sample under study, with migration following an Arrhenius relationship between 20 and 150 °C (Haldimann et al., 2013).

The 62% describes one sample and measures mobility rather than exposure. The same Polymers Communiqué article states the other half: there is yet no incontrovertible evidence that antimony present in polyesters leach out into the products at concentrations above permissible level (WHO: 20 μg/L, US: 6 μg/L, EU: 5 μg/L), and the search for an alternative continues on that basis.

That search has not succeeded. The article closes by saying so: In spite of many efforts, no viable alternative to antimony is within sight. It looks as though PET industry and users will have to live with antimony for many more years to come. A titanium-citrate catalyst does exist and one supplier reports it at 10 ppm, which is an alternative to the antimony catalyst rather than to the antimony problem.

Why does glass need antimony?

Glassmakers use antimony oxide as a fining agent, which means it makes bubbles leave the melt before the glass sets. A review of fining agents calls antimony oxide one of the most efficient chemical fining agents, especially when used in combination with alkali nitrates in a batch, and then makes a narrower claim than the substitution literature usually allows: Fining by arsenic (and antimony) compounds is irreplaceable for special applications, where a very high quality of glass or very high melting temperatures are needed (Influence of fining agents on glass melting).

The review names the applications: pharmaceutical glasses, display glasses and glass ceramics. The wider glass industry runs on sodium sulphate as its fining agent, which is what makes the antimony route a specialty rather than a default.

Antimonial lead is a loop with a measured size

Battery antimony uses differ from the rest because part of the material returns. The USGS describes the circuit: the bulk of secondary antimony is recovered at secondary lead smelters as antimonial lead, most of which was generated by, and then consumed by, the lead-acid battery industry, and recycling supplied 12% of estimated domestic apparent consumption (USGS).

Twelve percent is the size of the loop, and it is a minority of consumption. The grid is collected and smelted and cast again, so part of the next year’s requirement comes out of last year’s scrap. The USGS lists combinations of calcium, copper, selenium, sulfur and tin as substitutes for battery alloys. The rest of the material guides follow the same split between grade, form and supply.

What are the smaller antimony uses?

The 11% nonmetal heading holds ceramics, glass, rubber and the rest of the small antimony uses. Colour is one of the jobs inside it: the fining review notes that antimony oxide, “in combination with antimony sulphide”, is well used as a glass colourant and is known as ‘antimony ruby’, and that the two form a complex when the glass is reheated.

The pharmacology review gives a longer list under the same heading, naming textiles, enamels, ceramics, pigments and fireworks, and adding catalysis as a separate line.

What reaches a patient is a different compound

The medical use is the oldest recorded one and the least like the others. Potassium tartrate, tartar emetic, was given for fever, pneumonia, congestion, inflammation and sedation; the StatPearls review records cosmetics use in Asia and the Middle East, and topically for herpes, leprosy, mania and epilepsy (StatPearls).

What survives into current practice uses pentavalent antimony rather than the trivalent tartrate: meglumine antimoniate and sodium stibogluconate, given for leishmaniasis and schistosomiasis, and in aversive treatment for substance use. The review offers tolerance first among its reasons for the switch, then efficiency and cost.

• Trivalent antimony is the older pharmacology: the tartrate, the trichloride, the trisulfide, and the group that includes the industrial oxide.
• Pentavalent antimony is the modern drug form, supplied as meglumine antimoniate and sodium stibogluconate.

For anyone reading a supply-chain document, this section is a warning about the word. A pharmaceutical-grade antimoniate and a flame-retardant oxide share an element and very little else: different specification, different regulatory route, different customer.

What a buyer has to specify

Four questions separate an antimony enquiry from an antimony order.

1. Which form. An oxide, a sulfide, an alloy, a tartrate and a pentavalent drug salt answer to the same element and each carries its own specification.
2. Which grade. A 99.5% oxide and a 99.8% oxide are both sold as antimony trioxide, and the assay is the smallest part of what separates them. The grade page carries the table.
3. Which end use. The flame-retardant buyer is buying a component of someone else’s system, the PET producer is buying a catalyst, and the glassmaker is buying a fining agent.
4. Which control line. The Chinese entry for antimony oxide is written as an assay threshold rather than an application, and the flame-retardant grades sit below it; the grade page sets out the threshold, and the notice on Notice No. 72 sets out which paragraph is suspended and until when.

Methodology

The consumption split, the recycling rate, the substitute lists and the alloy grouping are from the USGS Mineral Commodity Summaries 2026 chapter on antimony, which reports 2025 estimates. The compound inventory, the medicinal history and the trivalent and pentavalent distinction come from the StatPearls review, which is a clinical text; where it and the USGS group things differently, both are quoted on their own terms rather than reconciled. The flame-retardant formulation share and the substitution argument are Clariant’s, and Clariant sells a competing product line. The glass fining behaviour, the specialty applications and the antimony ruby chemistry come from the 2017 fining review. The catalyst dose, the market share, the food-contact limits and the article’s own closing conclusion come from the 2016 Polymers Communiqué article. The 62% is a single-sample measurement and is reported with the study’s own scope.

Sources

USGS, Mineral Commodity Summaries 2026: Antimony. 2026. https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-antimony.pdf

Martin R, Lee VR. Antimony Toxicity. StatPearls Publishing, 2024. https://www.ncbi.nlm.nih.gov/books/NBK608003

Clariant. Halogen-free flame retardants: sidestepping the antimony market volatility. 17 June 2025. https://www.clariant.com/pt/Corporate/Blog/2025-Blog-Posts/06/Halogen-Free-Alternatives-Sidestepping-Antimony-Volatility

Hujová M, Vernerová M. Influence of fining agents on glass melting: a review, Part 1. Ceramics-Silikáty 61(2), 2017. https://pdfs.semanticscholar.org/2e6c/dac54852ad003f4010ff4c8a9f210b92e5a4.pdf

Haldimann M, et al. Migration of antimony from PET trays into food simulant and food. Food Additives & Contaminants: Part A, 2013. https://www.ebi.ac.uk/europepmc/webservices/rest/search?query=PMC3613973

Sivaram S. Antimony-free Polyesters. Polymers Communiqué, June-July 2016. http://www.swaminathansivaram.in/media/data/Antimony-free%20Polyesters.pdf