Antimony

What is Antimony?

Antimony is element 51, symbol Sb from the Latin stibium, a brittle grey metalloid sitting directly below arsenic in group 15 of the periodic table. It has no known biological function in humans. No enzyme requires it, no transport protein has been identified for it, and no deficiency state has ever been produced in any species. It makes up roughly 0.2 parts per million of the Earth's crust, the 63rd most abundant element. Nobody sells it as a supplement, and the reason it belongs in this archive is packaging rather than product. In 2017, world antimony consumption ran approximately 48 percent flame retardants, 33 percent lead-acid battery alloy and 8 percent plastics. That last slice is antimony trioxide used as the polycondensation catalyst for polyethylene terephthalate, and it is the reason a few hundred nanograms of antimony per liter show up in the bottled water, juice and PET-packed supplements in your kitchen.

Common Names

• Antimony, elemental, CAS 7440-36-0

• Sb, from stibium, the symbol assigned by Berzelius

• Antimony trioxide, diantimony trioxide, Sb2O3, CAS 1309-64-4

• Stibnite, antimony trisulfide, Sb2S3, the principal ore mineral

• Kohl, surma, kajal, ithmid, when stibnite is ground for use as eye cosmetic

• Tartar emetic, antimony potassium tartrate, K2Sb2(C4H2O6)2

• Pentostam, sodium stibogluconate, and Glucantime, meglumine antimoniate

• Stibine, SbH3, the hydride gas

Primary Active Compounds

• Antimony trioxide (Sb2O3). The industrial workhorse. Flame retardant synergist, glass fining agent, and the PET catalyst. NTP listed it in the 15th Report on Carcinogens in 2021 as reasonably anticipated to be a human carcinogen. EU CLP harmonised classification is Carc. 2, H351, plus STOT RE 2, H373.

• Trivalent antimony, Sb(III). The reactive oxidation state, responsible for essentially all classical antimony poisoning. IARC Monographs Volume 131 classified it Group 2A, probably carcinogenic to humans.

• Pentavalent antimony, Sb(V). Less reactive and less toxic. IARC Group 3, not classifiable. The oxidation state of the two antimonial drugs still in clinical use, and the dominant species that migrates out of PET.

• Antimony potassium tartrate. The most toxic trivalent salt in historical medical use. Doses as low as 0.2 g have been reported as fatal in adults.

• Stibine (SbH3). A hemolytic gas generated when antimony alloys contact acid. Occupational hazard only.

Key Note

Antimony is not one substance for toxicological purposes. It is at least four, and they behave differently enough that a single number labelled "antimony" on a certificate of analysis tells you little without speciation. The World Health Organization guideline value of 20 µg/L for drinking water and the US EPA maximum contaminant level of 6 µg/L are both written as total antimony, which is convenient for regulators and imprecise for risk.

The rest of this issue treats antimony as an exposure to be quantified rather than an intake to be optimized.

Primary Functions & Benefits

Antimony performs no function in human physiology, so this section describes what it does chemically and industrially instead, because those are the only functions it has.

In materials. Antimony trioxide is added at 2 to 10 percent alongside brominated compounds in flame-retardant textiles and plastics, where it forms antimony halides in the flame and interrupts radical chain propagation. In PET manufacture it is used at far lower loadings, catalyzing the polycondensation step and converting largely to antimony glycolate complexes that remain distributed through the finished polymer at 180 to 550 ppm. Titanium and germanium catalyst systems exist as commercial alternatives and produce PET with far lower residual antimony, but they cost more and antimony has held the position for decades.

In parasitology. Pentavalent antimonials are the only place antimony still has a legitimate therapeutic role. Sodium stibogluconate, marketed as Pentostam, and meglumine antimoniate, marketed as Glucantime, remain in use against visceral and cutaneous leishmaniasis. They are given parenterally, by a clinician, at doses calculated per kilogram of body weight, and they are used because the alternatives in the affected regions are expensive, scarce or also toxic. Their existence is not an argument that antimony is good for you. It is an argument that leishmaniasis is worse.

In everything else. No function. No antioxidant role, no cofactor role, no structural role, no signaling role. The comparison is molybdenum, a genuine trace element with a human requirement of 45 µg per day and four known human molybdoenzymes. Antimony has zero.

Forms & Standardization

This section is the toxicology of each chemical form rather than a guide to buying any of them, because the differences between antimony species span three orders of magnitude in hazard and every regulatory number is written as if they did not.

Antimony trioxide, Sb2O3, CAS 1309-64-4. The form with the carcinogenicity data. NTP Technical Report 590, published 2017, exposed Wistar Han rats and B6C3F1/N mice by inhalation to 0, 3, 10 or 30 mg/m3 for two years. The conclusion was clear evidence of carcinogenic activity in male and female mice, based on alveolar/bronchiolar carcinoma, skin fibrous histiocytoma in males and malignant lymphoma in females, and some evidence in male and female rats, based on lung tumors and adrenal medulla pheochromocytoma. California listed antimony trioxide under Proposition 65 in 1990. OEHHA's proposed No Significant Risk Level is 0.13 µg per day, derived from a human cancer slope factor of 5.2 per mg/kg-day applied to the female mouse data. Note that every one of these findings comes from inhalation. There is no comparable oral carcinogenicity dataset.

Trivalent antimony as a class. IARC Monographs Volume 131, evaluated at a meeting held remotely from 2 to 18 March 2022 and published in 2023, placed trivalent antimony in Group 2A, probably carcinogenic to humans, on limited human evidence, sufficient animal evidence and strong mechanistic evidence. This supersedes the older Group 2B classification given to antimony trioxide in IARC Volume 47 in 1989. California, evaluating the same monograph, concluded on 8 June 2023 that trivalent antimony compounds as a class did not meet the Labor Code criteria for automatic Proposition 65 listing, while leaving the 1990 antimony trioxide listing untouched. Two agencies, one dataset, two defensible answers.

Antimony potassium tartrate, tartar emetic. The trivalent salt with the longest and worst medical history. Water-soluble, rapidly absorbed, and directly cardiotoxic. UK poisons information records a fatal adult dose reported at 0.2 g, though outcome is variable enough that a three-year-old who swallowed 2.3 g of the compound from a liquid ant killer survived with treatment. Gastrointestinal symptoms begin 30 minutes to 2 hours after ingestion. Severe cases progress to hemorrhagic gastritis, myocardial depression, shock, acute kidney injury and convulsions. The United States banned it in 1941 as a patent medicine for alcohol intoxication.

Pentavalent antimonials. Sodium stibogluconate and meglumine antimoniate are the clinically used forms and are markedly less toxic per milligram of antimony than the trivalent salts. They are still not benign. In a prospective series of 67 returned travellers treated for New World cutaneous leishmaniasis, 95.5 percent reported at least one adverse reaction, myalgia in 59.6 percent, mean peak alanine transaminase rise of 107 IU/L by day 13, QTc prolongation in 9 of 67 patients between days 4 and 19 with values from 422 to 524 ms, and 17.9 percent had treatment disrupted by toxicity. That is the profile of a drug given under electrocardiographic monitoring, not something with an oral analogue.

Stibnite, Sb2S3. The ore, and the traditional kohl mineral. Poorly soluble, which limits absorption, but "poorly soluble" is not "inert" and it is frequently not what is actually in the tube. Analyses of kohl sold in Europe and the Gulf repeatedly find galena, lead sulfide, rather than stibnite, which converts a modest antimony question into a serious lead one.

Antimony glycolate complexes in PET. Not a form anyone standardizes, but the form that matters for consumers. The catalyst does not remain as discrete Sb2O3 in the finished bottle. Migration studies consistently find pentavalent antimony as the dominant species in the leachate, which is the least toxic oxidation state, and that is a genuinely reassuring detail that almost never survives into consumer coverage.

Food Sources

For a substance with no biological role, this section is routes of exposure rather than sources of nutrition, and the ranking of those routes is not what most people expect.

Ordinary diet. Health Canada's guideline technical document estimates general population antimony intake at 0.019 to 0.057 µg per kilogram of body weight per day. For a 70 kg adult that is roughly 1.3 to 4.0 µg per day. Food and beverages account for 68 to 80 percent of dietary exposure and drinking water for 17 to 29 percent. Exclusively breast-fed infants have the highest body-weight-normalized intake, with a median of 0.259 µg/kg per day and a 95th percentile of 0.306. All of these sit far below the WHO tolerable daily intake of 6 µg/kg body weight per day.

PET bottled water. This is the route the reader actually has. Shotyk, Krachler and Chen, publishing in the Journal of Environmental Monitoring in 2006, measured pristine Canadian groundwater at 2.2 plus or minus 1.2 ng/L of antimony. The same class of water sold in PET bottles came in at 156 plus or minus 86 ng/L across 12 Canadian brands. Forty-eight European brands in PET had a median of 343 ng/L with a range around 253 to 546 ng/L. Water sold in polypropylene, which uses no antimony catalyst, came in at 8.2 plus or minus 0.9 ng/L. The polymer is the variable, not the spring.

The temperature curve. Westerhoff's nine US brands spanned 0.095 to 0.521 µg/L at purchase. Leaching followed a power function of temperature, k = 8.7 x 10^-6 x T^2.55, giving a time-to-6-µg/L of 176 days at 60 degrees C, 12 days at 70 degrees C and 1.3 days at 85 degrees C. HDPE released no detectable antimony at all. Fan and colleagues, working with 16 Chinese brands in 2014, found the same shape: 1.88 to 8.32 ng/L after a week at 4 degrees C, 2.10 to 18.4 ng/L at 25 degrees C, and 20.3 to 2,604 ng/L at 70 degrees C.

Hot climates. A Kuwaiti study found bottled water stable at 0.247 to 0.511 µg/L over three months at 25 degrees C, then 8.530 µg/L after 24 hours at 50 degrees C and 16.8 µg/L after seven days at 50 degrees C. Fifty degrees C is a parked car in July, or a pallet on an unshaded dock. This is the single realistic scenario in which PET-packaged product exceeds a drinking water limit.

Juices and cordials. Hansen and colleagues, Journal of Environmental Monitoring 2010, analysed 42 beverages representing 28 products from 16 brands and found eight that exceeded the EU drinking water limit of 5 µg/L. The highest ready-to-drink value was 13.6 µg/L in a sour cherry juice, and undiluted cordials reached 12.3, 30.2 and 44.7 µg/L. The honest complication is that the highest-antimony brand showed elevated levels even in Tetra Pak cartons, which points at an ingredient or a piece of processing equipment rather than at the container. Blaming PET for that result would be wrong.

Supplement packaging specifically. PET, resin identification code 1, is the standard clear packer bottle for capsules, softgels and gummies, because buyers want to see the product. HDPE, code 2, is standard for powders and moisture-sensitive material because it is the better barrier, and it is the resin that released no detectable antimony in Westerhoff's testing. Most protein powder tubs are HDPE, so they are not an antimony route at all, while the clear gummy jar and the clear capsule bottle are. Even there the arithmetic is unfavorable to alarm: a dry powder or a capsule offers essentially no aqueous phase for antimony to partition into, and migration into dry solids runs orders of magnitude below migration into water. The PET supplement container that matters is the one holding a liquid, stored above about 40 degrees C.

Kohl and traditional eye cosmetics. Stibnite-based kohl remains available in imported and online markets. The FDA has issued standing warnings about kohl, kajal, al-kahal, surma, tiro, tozali and kwalli, and the driving hazard in sampled products is lead rather than antimony, because many products marketed as antimony kohl are actually galena. Applied to the conjunctival margin, on infants, daily.

Adulterated and traditional remedies. Antimony appears in Unani kushta preparations and in mineral remedies of the sang-e-surma type, where the intended ingredient is antimony sulfide and the delivered ingredient is often lead sulfide. This is the route where doses jump from micrograms to milligrams, and it is a categorically more serious problem than any packaging question in this issue.

Occupational and ambient. Background ambient air is typically below 20 ng/m3, rising above 1,000 ng/m3 near smelters. Median US groundwater antimony from 1992 to 2003 was below 1 µg/L. China accounted for roughly 54.5 percent of world mine production in 2022, Russia 18.2 percent, Tajikistan 15.5 percent.

Who Should Take Antimony

No one should take antimony. There is no population, no age group, no health condition and no clinical scenario in which oral antimony is appropriate, and no legitimate product contains it as an intended ingredient.

Who is unavoidably exposed. Everyone, at low levels, through diet and drinking water. Anyone drinking bottled water or PET-packaged beverages stored warm. Workers in antimony smelting, flame retardant compounding, PET resin production, glass manufacture, lead-acid battery plants and firing ranges. Residents near smelters and antimony mines. Users of imported kohl and mineral-based traditional remedies.

Who is treated with it, under supervision. Patients with visceral or cutaneous leishmaniasis receiving pentavalent antimonials, prescribed by an infectious disease specialist and administered parenterally with electrocardiographic and hepatic monitoring. This is a supervised drug exposure, not a supplement.

Who should consider testing. Anyone with an occupational history in the industries above and unexplained respiratory, cardiac or gastrointestinal symptoms. Anyone using imported kohl or an unlabeled traditional mineral preparation, in which case the test to order is a full heavy metal panel including lead, because lead is the more likely finding. Testing means blood and urine antimony measured by ICP-MS through a clinical laboratory. Hair analysis and provoked or challenge urine testing are not validated for this and will produce numbers that cannot be interpreted.

Who Should AVOID or Use Caution

Contraindications

• Everyone, for any oral antimony product. There is no exception.

• Any imported cosmetic or traditional preparation described as antimony, surma, kohl, kajal, ithmid or sang-e-surma, particularly for use on or near children.

• Pentavalent antimonials are contraindicated where cardiac monitoring is unavailable, and in patients with significant pre-existing cardiac, hepatic or renal disease, where the risk calculus changes sharply.

Use Caution

• PET-packaged liquids stored above roughly 40 degrees C, including bottles left in vehicles, on loading docks or in unconditioned warehouses. The temperature effect is real and quantified.

• Long-dated PET-packaged product. Migration is cumulative, and the Shotyk data show measurable rises over months even under refrigeration, from about 2 ng/L in the source water to roughly 50 ng/L after 37 days chilled.

• Reused or repeatedly refilled PET bottles, particularly any that have been through a dishwasher or filled with hot liquid.

• Pregnancy and infancy, where the relevant caution is avoiding kohl and mineral remedies entirely rather than avoiding bottled water.

• Occupational exposure. The OSHA permissible exposure limit and the NIOSH recommended exposure limit are both 0.5 mg/m3 as an eight-hour time-weighted average, and the IDLH is 50 mg/m3.

Critical Safety Point

The gap between the two exposure routes in this issue is roughly a thousandfold, and treating them as one topic is the mistake that makes antimony coverage useless. A bottle of water at 0.2 µg/L delivers about 0.4 µg of antimony across two liters, against a WHO tolerable daily intake of 420 µg for a 70 kg adult. A mislabeled mineral remedy or a kohl product used daily on an infant's eyelid can deliver milligram-scale doses of antimony, lead or both. Precision about which one you are dealing with is the entire safety message.

Recommended Dosages

There is no recommended dosage of antimony, no adequate intake, no reference daily intake and no upper limit expressed as a supplement dose, because antimony has no biological requirement. Every number below is a regulatory ceiling on contamination or exposure, and none of them is an amount to consume.

Drinking water ceilings

• World Health Organization guideline value: 0.02 mg/L, 20 µg/L. Derived from a tolerable daily intake of 6 µg/kg body weight per day, itself based on a NOAEL of 6.0 mg/kg body weight per day in a 90-day rat drinking water study of potassium antimony tartrate, with an uncertainty factor of 1,000, then allocating 10 percent of the TDI to water for a 60 kg adult drinking 2 L/day.

• US EPA maximum contaminant level and MCL goal: 0.006 mg/L, 6 µg/L.

• US FDA bottled water allowable level, 21 CFR 165.110: 0.006 mg/L. Same number as EPA, applied to bottled product.

• EU parametric value for drinking water: 5 µg/L, the value set in Annex I Part B of Directive 98/83/EC and carried into national law, including the French Public Health Code and the UK prescribed concentration or value.

• Health Canada maximum acceptable concentration: 0.006 mg/L.

• Japan: 2 µg/L, the strictest of the set.

Food contact material ceiling

• EU specific migration limit under Regulation (EU) No 10/2011, Annex II: 0.04 mg per kg of food or food simulant, expressed as antimony, which is 40 µg/kg. Antimony salts are not authorised for use as additives under Article 6(3)(a); the SML governs migration out of the polymer.

• The United States has no equivalent. The FDA has not specified a migration limit for antimony from PET.

Pharmaceutical and supplement ceilings

• USP General Chapter <232> and ICH Q3D classify antimony as a Class 3 element with a permitted daily exposure of 1,200 µg/day oral, 90 µg/day parenteral and 20 µg/day inhalation. For comparison, oral PDEs are 5 µg/day for lead and cadmium, 15 for arsenic and 30 for mercury.

• USP General Chapter <2232>, the chapter that actually governs elemental contaminants in dietary supplements, limits only arsenic, cadmium, lead and mercury. Antimony is not in it.

Occupational ceilings

• OSHA PEL and NIOSH REL: 0.5 mg/m3 TWA as Sb. IDLH 50 mg/m3.

• ATSDR minimal risk levels: 0.001 mg Sb/m3 acute and intermediate inhalation, 0.0003 mg Sb/m3 chronic inhalation, and 1 mg Sb/kg/day acute oral. ATSDR declined to derive intermediate or chronic oral MRLs, which is itself a statement about the state of the oral database.

Duration

Not applicable in any consumer sense. The only durations that matter are the storage duration of PET-packaged liquid, discussed above, and the clinical course of pentavalent antimonials, which runs 20 to 28 days of daily parenteral dosing under supervision.

Timing & Administration

Nothing about antimony is timed by the reader, so the timing that matters is the interaction of storage time and storage temperature in PET packaging, plus the clinical schedule of the two antimonial drugs.

Storage time. Migration from PET is cumulative and does not plateau quickly. Shotyk's group tracked water that started at 2.2 ng/L, reached roughly 50 ng/L after 37 days refrigerated, and rose into the hundreds of ng/L over three to six months at room temperature. Fan's Chinese series found release still increasing across four weeks, though the rate declined with time.

Storage temperature. The dominant term. Westerhoff's exponent of 2.55 is why the time-to-limit at 22 degrees C and at 80 degrees C differ by a factor of well over a hundred.

Practical handling. Buy PET-packaged liquid from conditioned retail rather than an outdoor display. Do not leave bottles in a vehicle. Do not refill a PET bottle with hot liquid or run it through a dishwasher. Move an opened PET-packaged liquid supplement to the refrigerator. Prefer HDPE, glass or aluminum where the format allows. None of this is urgent, and all of it is free.

Clinical administration. Sodium stibogluconate is given by slow intravenous injection and meglumine antimoniate by intramuscular or intravenous injection, both daily for 20 to 28 days, with baseline and serial electrocardiography, transaminases, amylase and full blood count. There is no oral formulation of either, and there is no legitimate reason for a consumer to encounter one.

Timeline of Effects

There is no therapeutic timeline for antimony, so this is the timeline of exposure and of toxicity, drawn from the poisoning literature and the clinical trial record.

Acute oral trivalent antimony. Nausea, vomiting, abdominal pain and diarrhea begin 30 minutes to 2 hours after ingestion. A garlic odor on the breath may be present. Severe cases progress within hours to hemorrhagic gastritis, hypotension, myocardial depression and electrolyte derangement, with acute kidney injury and cerebral edema in the worst outcomes.

Pentavalent antimonial therapy. Toxicity is cumulative and arrives late. In the traveller series, transaminases peaked around day 13, QTc prolongation appeared between days 4 and 19, and malaise was reported by 29.8 percent by week three. Monitoring intensifies rather than relaxes as a course proceeds, which is the opposite of how a supplement timeline reads.

Chronic low-level exposure. No timeline can honestly be given, because no human study has established a dose-response relationship for chronic oral antimony at environmental concentrations. The EPA's stated health effects at chronic exposure above the MCL, an increase in blood cholesterol and a decrease in blood sugar, come from rodent drinking water studies, not from a human cohort.

PET migration. Days to months, governed by temperature. There is no acute event here at all.

Benefits of Taking Antimony

There are no benefits to taking antimony. Not one. Everything below is history, presented as history, because it explains how a substance with no biological role held a place in European medicine for three centuries.

The alchemical era. Paracelsus, 1493 to 1541, moved European therapeutics toward mineral remedies, and antimony was the mineral that carried the movement. Triumph Wagen Antimonii, published at Leipzig in 1604 under the name Basil Valentine, made the case at length. There was no Basil Valentine. No such name appears on Benedictine rolls in Germany or Rome and no mention of him predates 1600. The likeliest author is Johann Thölde, a salt manufacturer, roughly 1565 to 1624. The Latin edition, Currus triumphalis antimonii, followed in 1646.

The antimonial cup. A vessel cast from antimony-lead alloy. Wine left in it overnight dissolved enough antimony tartrate to induce violent vomiting and purging, which was the intended effect under humoral theory. The Royal College of Physicians' cup was purchased by Baldwin Hamey Junior in 1637 and is credited with at least two patient deaths. Such cups were still sold in the late eighteenth century.

The everlasting pill. A ball of metallic antimony, swallowed, which provoked a bowel movement and was then recovered, washed and reused. Dr J. A. Paris noted that a single pill would serve a whole family for their lives and might be transmitted as an heirloom.

The antimony wars. France banned antimony from 1566 and the prohibition held for roughly a century of open argument. Guy Patin, dean of the Paris faculty and the most quotable opponent, left the line "May God protect us from such drugs and physicians!" The ban collapsed not on evidence but on the recovery of a sufficiently important patient.

The parasitological era. The one stretch where antimony did real work. Antimony potassium tartrate was tested against trypanosomiasis in 1906, used in leishmaniasis from 1913, and shown effective against schistosomiasis by John Brian Christopherson in 1918. It was curative and dangerous in equal measure, displaced by pentavalent antimonials and then by praziquantel by the 1970s. What survives is pentavalent antimony for leishmaniasis, which is a drug of last resort for a parasitic disease, not a benefit of taking antimony.

The debunked claim. In the 1990s Barry Richardson proposed that fungal action on antimony flame retardants in cot mattresses generated stibine and caused sudden infant death syndrome. The UK Department of Health convened an expert group, and its 1998 report, authored by S. Limerick with M. Cooke, S. Chantler, G. Draper, G. Fell, P. J. Fleming, W. Holland and J. Keeling, ran to 369 pages and found no support for the hypothesis. Worth remembering as an example of an antimony scare investigated properly.

Potential Negatives & Side Effects

From environmental exposure at measured levels. No documented adverse effect in humans. Measured dietary and bottled-water intakes sit one to two orders of magnitude below the WHO tolerable daily intake of 6 µg/kg body weight per day. Stating this plainly is not minimizing the issue. It is the finding.

From pentavalent antimonial therapy. Cardiotoxicity with QTc prolongation and rare tachyarrhythmia, reversible transaminase elevation, pancreatitis with amylase and lipase rise, arthralgia and myalgia, anemia, leukopenia, thrombocytopenia, headache, nausea and rash.

From acute trivalent antimony ingestion. Corrosive gastroenteritis, hemorrhagic gastritis, myocardial depression, shock, acute kidney injury, cerebral edema and convulsions. Treatment is supportive with ECG monitoring, and chelation with dimercaprol, DMSA or DMPS is considered under specialist guidance.

From inhalation. Antimony trioxide is the form with the carcinogenicity signal, and it comes from occupational dust rather than from anything in a kitchen. Chronic inhalation in animal studies produced interstitial inflammation, and the ATSDR chronic inhalation MRL of 0.0003 mg Sb/m3 rests on Newton and colleagues' 1994 one-year rat study.

From stibine. Hemolysis, hemoglobinuria and acute kidney injury. An industrial accident scenario, not a consumer one.

Deficiency Symptoms

Antimony deficiency does not exist and cannot exist, because antimony has no biological function in humans and no metabolic pathway depends on it. No enzyme uses it as a cofactor, no receptor binds it, no transporter has evolved for it, and no experimental animal has ever been made antimony-deficient. Anyone claiming symptoms of low antimony is describing something that has never been observed.

What antimony addresses

Nothing nutritionally. In one narrow clinical setting, pentavalent antimony addresses infection with Leishmania species, and it does so as a parenteral prescription drug with a 20 to 28 day course and monitoring for cardiac and hepatic toxicity.

Bottom line

The contrast worth holding is selenium. Selenium is an actual trace element with an RDA of 55 µg per day for adults, a defined deficiency disease in Keshan disease cardiomyopathy, at least 25 human selenoproteins, and a tolerable upper intake level of 400 µg per day. Every one of those four things is missing for antimony. When a substance has a requirement, a deficiency syndrome, identified proteins and an upper limit, it is a nutrient. Antimony has a maximum contaminant level and nothing above it.

Toxicity Symptoms

At high intake

• Oral trivalent antimony, milligram to gram scale: vomiting within 30 minutes to 2 hours, abdominal pain, profuse diarrhea, garlic breath odor, hemorrhagic gastritis, hypotension and cardiac depression. A fatal adult dose of antimony potassium tartrate has been reported at 0.2 g, with survival documented at 2.3 g in a young child, so the dose-response is wide.

• Therapeutic pentavalent antimony, 20 mg Sb(V) per kg per day: cumulative cardiac, hepatic and pancreatic toxicity emerging in weeks two and three of a course.

• Inhaled antimony trioxide dust above 0.5 mg/m3 TWA: airway irritation, pneumoconiosis with prolonged exposure, and the carcinogenicity signal described above. IDLH is 50 mg/m3.

• Stibine gas: hemolysis, dark urine, jaundice, kidney failure.

Signs to reduce or stop

There is no consumer intake to reduce, so the actionable signals are exposure signals. Persistent metallic taste, unexplained recurrent vomiting or diarrhea in a household using an imported mineral remedy, a new arrhythmia or palpitations in someone on antimonial therapy, or respiratory symptoms in someone with occupational antimony dust exposure. Any of those warrants blood and urine antimony by ICP-MS, and in the case of a traditional remedy or kohl, a full heavy metal panel including lead.

General note

The realistic hazard profile splits cleanly. Environmental antimony from packaging has never been shown to injure anyone at measured concentrations. Deliberate ingestion of antimony-containing mineral preparations, and daily cosmetic application of products sold as antimony kohl, have both produced documented heavy metal poisoning, usually with lead as the culprit. Treating those two situations with the same level of concern is the error, in both directions.

How Antimony Works

Antimony works by oxidation state, and everything that matters about it follows from whether it is trivalent or pentavalent at the point of contact with tissue.

Trivalent antimony and thiols. Sb(III) has high affinity for sulfhydryl groups. It binds cysteine residues and glutathione, which inactivates thiol-dependent enzymes, depletes reduced glutathione and shifts the intracellular redox balance toward oxidative stress. The NTP's Report on Carcinogens monograph on antimony trioxide identifies oxidative stress, DNA damage and chromosomal instability as the mechanistic support for its listing, and IARC's Volume 131 evaluation cited strong mechanistic evidence in human primary cells for trivalent antimony specifically. The same thiol chemistry explains the myocardial depression and the gastrointestinal corrosion, and it is why trivalent antimony behaves more like arsenic than like a nutrient metal.

Pentavalent antimony as a prodrug. Sb(V) is comparatively unreactive and poorly taken up by mammalian cells. Its antileishmanial activity depends on reduction to Sb(III) inside the parasitized macrophage, where the trivalent species then disrupts the parasite's trypanothione-based thiol redox system, which is chemically distinct from the human glutathione system. That differential is the whole therapeutic window, and it is narrow. It also explains why treatment failure spread so widely in Bihar state in India, where reduction and efflux mechanisms in resistant Leishmania donovani strains eroded efficacy badly enough that pentavalent antimony was effectively abandoned as first-line therapy there.

Why PET leachate is the mild case. The antimony that migrates out of PET is predominantly pentavalent, the oxidation state IARC declined to classify as carcinogenic at all, at concentrations in the hundreds of nanograms per liter. The carcinogenicity data driving every antimony regulation come from inhaled trivalent antimony trioxide particles in two-year rodent studies at 3 to 30 mg/m3. Those are different chemistry, different route and a different dose scale by many orders of magnitude, and any account that connects them without saying so is misleading you.

Synergistic Supplements

Nothing is synergistic with antimony, because antimony has no beneficial effect to potentiate. The relevant question is what modifies antimony absorption, retention or toxicity.

• Glutathione and cysteine status. Trivalent antimony is detoxified largely through thiol conjugation and biliary excretion, so thiol depletion is expected to worsen trivalent antimony toxicity. This is mechanistic reasoning and animal data, not a human intervention finding, and no supplement has been shown to reduce antimony body burden in people.

• Selenium. Frequently promoted as a universal heavy metal antagonist on the strength of its genuine interaction with mercury. There is no human evidence that selenium supplementation alters antimony toxicokinetics, and taking selenium for this purpose adds a real upper-limit risk at 400 µg per day for no demonstrated return.

• Chelators sold as supplements. Chlorella, cilantro, modified citrus pectin, zeolite and humic or fulvic products are marketed for heavy metal removal. None has controlled human data showing reduced antimony burden. Clinical chelation for antimony poisoning uses dimercaprol, DMSA or DMPS under specialist supervision, and those are drugs.

The only intervention with an evidence basis is reducing the exposure, which for the packaging route means controlling storage temperature.

Interactions & What NOT to Take

Drug interactions relevant to antimonial therapy. These apply to patients receiving pentavalent antimonials, not to environmental exposure.

• QT-prolonging drugs. Amiodarone, sotalol, methadone, haloperidol, ondansetron, macrolides such as azithromycin and clarithromycin, and fluoroquinolones such as moxifloxacin. QTc prolongation occurred in 13.4 percent of patients on stibogluconate monotherapy, and additive prolongation is the main serious interaction risk.

• Amphotericin B. Combined use raises the risk of arrhythmia and renal injury and requires specific monitoring.

• Hepatotoxic agents. Transaminase elevation is expected on antimonial therapy, so concurrent hepatotoxins add avoidable signal and avoidable risk.

• Drugs causing pancreatitis. Pentavalent antimonials raise amylase and lipase, and adding another pancreatitis-associated agent complicates interpretation and management.

What not to take, in the consumer sense.

• Any product sold as an antimony supplement, antimony trioxide, colloidal antimony or antimonial mineral preparation. There are no legitimate ones.

• Imported kohl, surma, kajal, ithmid, tiro, tozali or kwalli. The FDA warns about all of these by name, and the dominant hazard in sampled products is lead.

• Unlabeled Unani kushta or mineral preparations of the sang-e-surma type, where the stated ingredient is antimony sulfide and the delivered ingredient is frequently lead sulfide.

One nutrient note. No mineral supplement interacts meaningfully with environmental antimony at these concentrations, and any product implying otherwise is selling a solution to a problem it has not measured.

Quality, Testing & Adulteration

The quality problem with antimony is unusual, because the substance is not the product. It is in the container, and it is in the one regulatory gap that consumer-facing testing programs do not cover.

Antimony is not in USP <2232>. The USP chapter governing elemental contaminants in dietary supplements limits arsenic, cadmium, lead, mercury and methylmercury. Antimony is not among them. A supplement can carry a clean elemental contaminant certificate under <2232> without antimony ever having been measured. USP <232> and ICH Q3D do assign antimony a Class 3 oral permitted daily exposure of 1,200 µg/day, but those chapters govern pharmaceuticals, and 1,200 µg/day is roughly 3,000 times the antimony a person would get from two liters of typical PET bottled water.

The migration limit gap. The EU sets a specific migration limit of 0.04 mg/kg food under Regulation (EU) No 10/2011, which is 40 µg/kg. The EU drinking water parametric value for the same element is 5 µg/L. The packaging limit is therefore eight times looser than the drinking water limit for a substance that migrates from packaging into water. Filella's 2020 review flagged exactly this inconsistency, and also noted that the FDA has specified no migration limit for antimony from PET at all.

What third-party testing exists. NSF/ANSI 173 certification for dietary supplements, NSF Certified for Sport, and Informed Sport all test finished product for contaminants, with heavy metal panels typically built around lead, arsenic, cadmium and mercury. ConsumerLab publishes independent testing that likewise centers those four. USP's Dietary Supplement Verification Program applies <2232>. None of these programs routinely reports antimony, so a certification mark tells you nothing about it.

What a certificate of analysis should show. For any elemental contaminant claim, look for the analytical method named as ICP-MS with a stated limit of quantitation, the elements listed individually rather than as a "heavy metals" pass/fail, and a lot number matching the bottle in your hand. For antimony specifically, ask the brand two questions: what resin the container is made of, and whether they have ever measured antimony migration into finished product. Most will not have an answer to the second, and that answer is itself information.

Documented adulteration. The real adulteration story is not antimony in supplements. It is lead sold as antimony. Analyses of kohl and surma products marketed as antimony-based repeatedly identify galena, lead sulfide, as the principal mineral rather than stibnite. The same substitution pattern appears in mineral-based traditional remedies. If you own a product described as antimony kohl or sang-e-surma, the test to run is for lead.

What a buyer can actually verify. The resin identification code on the bottom of the container. Code 1 is PET and contains an antimony catalyst residue unless the manufacturer specifies a titanium or germanium system. Code 2 is HDPE and released no detectable antimony in Westerhoff's testing. Glass and aluminum contribute none. That single digit is more actionable than any certificate you are likely to be shown.

Special Considerations

Infants and children. Body-weight-normalized dietary antimony intake is highest in infancy, with exclusively breast-fed infants at a median 0.259 µg/kg per day, still far below the 6 µg/kg TDI. The genuine pediatric concern is kohl applied to the eyes of young children, and the hazard there is lead. Fan's worst-case model, 70 degrees C for four weeks, gave an estimated child intake of 1,430 ng/kg per day for one brand against an EPA-derived reference of 400 ng/kg per day. That is the only published scenario in which a child's PET-sourced intake exceeds a reference value, and it required conditions no real supply chain produces.

Pregnancy. No human data support harm from environmental antimony at measured concentrations, and none support safety either, because the studies have not been done. The reasonable position is the ordinary one: avoid traditional mineral remedies and imported cosmetics, and do not store PET-packaged drinks warm.

Hot climates and hot supply chains. The Kuwaiti data are the practical warning. Twenty-four hours at 50 degrees C took bottled water from under 0.5 µg/L to 8.53 µg/L, and a week at that temperature reached 16.8 µg/L. This is a solvable logistics problem and it is where regulatory attention would actually pay.

Recycled PET. Recycled content is rising across beverage and supplement packaging, and recycled PET carries the antimony history of every resin stream that went into it. Published comparisons of virgin versus recycled migration are not yet consistent enough to state a number, which is worth saying plainly rather than filling with a guess.

Occupational exposure at home. Indoor range use, soldering with antimony-containing alloys, and handling flame-retardant textile dust are the household-adjacent routes. None reaches the OSHA PEL of 0.5 mg/m3 in normal use.

Testing interpretation. Antimony has no clinical reference range a consumer can act on. Urinary antimony in the US general population fell 40 to 50 percent between the 1999-2000 and 2005-2006 NHANES cycles, so historical comparison values are not stable and a result labeled "elevated" against an old reference may mean nothing.

Research Status & Evidence Quality

Strong Evidence For

• Antimony trioxide is carcinogenic to rodents by inhalation. NTP TR-590, 2017, two years at 0, 3, 10 and 30 mg/m3.

• Antimony migrates from PET into aqueous contents at a rate that rises steeply with temperature.

• Measured antimony in PET bottled water sits well below every drinking water limit under normal storage. Independent datasets from Canada, Europe, the United States and China converge on 0.1 to 0.5 µg/L, with Filella's 2020 review placing the typical median at 300 to 400 ng/L, against limits of 5, 6 and 20 µg/L.

• Trivalent antimony is substantially more toxic than pentavalent, consistent across acute poisoning, cellular mechanism and IARC's split of Group 2A versus Group 3.

• Pentavalent antimonials cure leishmaniasis and cause dose-related cardiac, hepatic and pancreatic toxicity in a large fraction of treated patients.

Moderate Evidence For

• Heating PET-packaged water above about 50 degrees C for a day or more can push antimony above the 6 µg/L EPA limit. Demonstrated in the Kuwaiti dataset and consistent with Westerhoff's kinetics, but from few studies.

• Elevated antimony in some commercial juices and cordials, up to 44.7 µg/L undiluted, with eight of 28 products above the EU 5 µg/L value. Attribution to packaging is not established, since the highest brand was elevated in cartons too.

• Kohl and traditional mineral remedies marketed as antimony frequently contain lead sulfide instead.

Emerging / Preliminary Evidence For

• Associations between urinary antimony and health outcomes in NHANES cross-sections. Correlational, and urinary antimony tracks recent exposure rather than body burden.

• Differences in migration between virgin and recycled PET. Studies exist, results are not yet consistent.

• Antimony speciation in leachate as a determinant of risk. The dominance of pentavalent antimony is well supported chemically, but no exposure assessment has been rebuilt around it.

Research Limitations

• There is no human oral carcinogenicity or chronic toxicity study of antimony at environmental concentrations. ATSDR declined to derive intermediate or chronic oral MRLs for that reason.

• The WHO guideline value of 20 µg/L rests on a 90-day rat study with an uncertainty factor of 1,000. A defensible regulatory choice, and not a human dose-response curve.

• Filella's 2020 review found systematic weaknesses in the PET leaching literature: detection limits too high, almost no study measuring source water before bottling, weak statistics, small samples and inconsistent reporting of bottle surface-area-to-volume ratio. The direction of the effect is solid. The precision claimed in individual papers is not.

• All regulatory limits are written as total antimony without speciation, conflating a Group 2A carcinogen with a Group 3 substance.

• No human trial has tested whether reducing PET-sourced antimony intake changes any health outcome, because the exposure is too small to power one.

Summary & Key Takeaways

Antimony is the rare entry in this archive where the thing everyone worries about is small and well quantified, and the thing nobody mentions is large and unmeasured. Element 51 has no biological role, no deficiency state and no legitimate place in a supplement. Every credible measurement of what actually comes out of PET puts it at 0.1 to 0.5 µg/L in normally stored bottled water, against limits of 5 µg/L in the EU, 6 µg/L at EPA and FDA, and 20 µg/L at WHO. Measured levels do not exceed those limits under ordinary conditions, and saying so clearly is more useful than manufacturing a scare.

Bottom Line

The exposure comes from the packaging, not the product, and at room temperature the packaging is not delivering a dose worth worrying about. Heat is the one variable that changes the answer, and 24 hours at 50 degrees C was enough to clear the EPA limit in the Kuwaiti data. The fix costs nothing. Keep PET-packaged liquids out of hot cars and off sunlit shelves, choose HDPE, glass or aluminum where the format allows, and read the resin code on the bottom of the container. The serious antimony exposures in the literature are not in anyone's grocery bag. They are in imported kohl and in mineral-based traditional remedies, where the labeled antimony is often actually lead, and where doses jump from micrograms to milligrams.

Key Safety Points

• No one should take antimony orally in any form. There is no product, dose or population for which it is appropriate.

• Trivalent antimony is Group 2A, probably carcinogenic. Pentavalent antimony is Group 3, not classifiable. What leaches from PET is predominantly pentavalent.

• The carcinogenicity evidence is inhalation evidence from 3 to 30 mg/m3 rodent studies. It does not transfer to nanogram-per-liter oral exposure without saying so.

• USP <2232> does not limit antimony in dietary supplements. A clean heavy metal certificate under that chapter means arsenic, cadmium, lead and mercury were checked, and antimony was not.

• Pentavalent antimonials are real drugs with real toxicity, 95.5 percent adverse reaction rate and 13.4 percent QTc prolongation in one 67-patient series. They belong to infectious disease specialists.

• If you use imported kohl, surma or a mineral remedy, test for lead first.

Special Note

Antimony is a useful case for a habit worth carrying to other shelves. When you cannot find the ingredient on any label, check the container, because the regulatory limit that governs what leaches out of packaging is often written by a different agency, at a different number, than the limit that governs what goes into the product. Here the EU allows 40 µg/kg to migrate from plastic into food while capping the same element at 5 µg/L in drinking water, and the United States sets no migration limit for antimony from PET at all. The gap between those numbers is not a scandal, and the levels people actually measure sit far below all of them. It is a reminder that the ingredient panel is only one of the two documents describing what you swallow, and nobody prints the other one.