Baby Safety / Compounds / Tributyltin oxide

Is Tributyltin oxide safe for babies and kids?

Very high risk for kids

Infants are more vulnerable to Tributyltin oxide than children or adults due to immature hepatic/renal clearance, higher intake-to-body-weight ratio, rapid organ development, and increased gastrointestinal absorption.

What is tributyltin oxide?

The IUPAC name is Tributylstannane oxide.

Also known as: Tributylstannane oxide, BIS(TRIBUTYLTIN) OXIDE, Hexabutyldistannoxane, Bis(tributyltin)oxide.

IUPAC name
Tributylstannane oxide
CAS number
56-35-9
Molecular formula
C12H27OSn
Molecular weight
310.98 g/mol
SMILES
CCCC[Sn](CCCC)(CCCC)O[Sn](CCCC)(CCCC)CCCC
PubChem CID
16682746

Risk for babies

Very high risk

Infants are more vulnerable to Tributyltin oxide than children or adults due to immature hepatic/renal clearance, higher intake-to-body-weight ratio, rapid organ development, and increased gastrointestinal absorption.

Neonates and infants up to 12 months have incomplete blood-brain barrier development, immature Phase I/II metabolic enzymes (particularly CYP3A4, UGT1A1), and higher gastrointestinal permeability. Equivalent doses produce higher internal concentrations and longer residence times.

What to do: Minimize infant exposure through source control. For breastfeeding mothers: reduce maternal exposure. For formula-fed infants: use certified low-migration bottles and verified water sources. Consult pediatrician regarding any concerns.

Risk for pregnant and nursing people

Severe risk

Pregnancy alters the metabolism and distribution of Tributyltin oxide, potentially increasing fetal exposure. The developing embryo/fetus is vulnerable during organogenesis (weeks 3-8) and neurological development. Placental transfer should be assumed.

Known reproductive toxicant (GHS H360) or confirmed endocrine disruptor. Placental transfer is presumed. Fetal exposure during critical developmental windows may cause structural malformations, growth restriction, or functional deficits.

What to do: Minimize exposure during pregnancy and lactation. Consult healthcare provider regarding specific risks. Consider alternative products with lower hazard profiles.

Regulatory consensus

4 regulatory and scientific bodies have classified Tributyltin oxide. The classifications differ — that's the data.

AgencyYearClassificationNotes
EPA—All antifouling registrations cancelled. Listed in TRI (Toxic Release Inventory). TSCA restrictions
IMO—BANNED under International Convention on the Control of Harmful Anti-fouling Systems (AFS Convention, 2008)
EU—Banned in antifouling. REACH Annex XVII restriction. CLP: Acute Tox 2, Repr 2, STOT RE 1, Skin Corr 1B, Aquatic Acute 1, Aquatic Chronic 1
Stockholm Convention—Under consideration for POPs listing. Already effectively banned through maritime regulations

Regulators apply different standards of evidence — animal-data weighting, exposure-pattern assumptions, epidemiological power thresholds — which is why two scientific bodies can review the same data and reach different conclusions. The disagreement is the data.

Where kids encounter tributyltin oxide

  • biocide in antifouling paints (historical)
  • wood preservative (restricted)
  • industrial catalyst
  • Legacy Contamination — Marine sediments at harbors, shipyards, drydocks worldwide, Contaminated dredge spoils, Former wood treatment sites
  • Historical Use (Banned) — Ship hull antifouling paint (banned 2008), Marine structure protection, Wood preservative (some uses banned)
  • Remaining Uses — Industrial biocide in some non-marine applications (limited), PVC stabilizer (being phased out)

Safer alternatives

Lower-risk approaches that achieve a similar outcome to Tributyltin oxide:

  • Copper-based antifouling paints (cuprous oxide)
    Trade-offs: Lower efficacy against slime-forming organisms. Copper accumulation in harbors. Requires more frequent repainting.
    Relative cost: 0.5-0.8×
  • Silicone-based foul-release coatings (Intersleek)
    Trade-offs: Requires vessel speed >15 knots for self-cleaning. Higher initial cost. Mechanical cleaning for slow vessels.
    Relative cost: 3-5× initial; lower lifecycle
  • DCOIT (Sea-Nine)
    Relative cost: 1.2-2×

Frequently asked questions

Is tributyltin oxide safe for kids?

Infants are more vulnerable to Tributyltin oxide than children or adults due to immature hepatic/renal clearance, higher intake-to-body-weight ratio, rapid organ development, and increased gastrointestinal absorption.

What products contain tributyltin oxide?

Tributyltin oxide appears in: biocide in antifouling paints (historical); wood preservative (restricted); industrial catalyst.

What should I do if my child is exposed to tributyltin oxide?

Minimize infant exposure through source control. For breastfeeding mothers: reduce maternal exposure. For formula-fed infants: use certified low-migration bottles and verified water sources. Consult pediatrician regarding any concerns.

Why do regulators disagree about tributyltin oxide?

Tributyltin oxide has been classified by 4 agencies including EPA, IMO, EU, Stockholm Convention, with differing conclusions. Regulators apply different standards of evidence (animal data weighting, exposure-pattern assumptions, epidemiological power thresholds), which is why two scientific bodies can review the same data and reach different conclusions. See the regulatory consensus table on this page for the full picture.

See Tributyltin oxide in the baby app

Look up products containing tributyltin oxide, compare to alternatives, and explore the full data record.

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Sources (1)
  1. ATSDR Toxicological Profile — CAS 56-35-9 — reference

Reference data, not professional advice. Aggregates publicly available regulatory and scientific data; not a substitute for veterinary, medical, legal, or regulatory advice. Why we built ALETHEIA →