At a glance
| Chemical family | Organotin — dialkyltin used as PVC heat stabilizer (also catalytic applications) |
| CAS number | 1002-53-5 |
| Classification | Not IARC classified. EU REACH Annex XVII Entry 20 restricts organotin in consumer articles to 0.1% tin by weight. Immunotoxic in animal studies (thymus atrophy, reduced immune function) |
| Where you encounter it | PVC mattress covers and protectors; vinyl flooring; PVC pipes and fittings; food-contact PVC packaging; catalysts in silicone production; indoor dust from PVC-containing products |
| Sleep micro-environment relevance | Present in PVC mattress covers and vinyl flooring — direct contact with the sleep environment. One of the most abundant organotins in indoor dust. Immunotoxic at higher exposures |
Regulatory & certification status
| European Union | REACH Annex XVII Entry 20 restricts dibutyltin compounds in articles at concentrations greater than 0.1% by weight of tin. Applies to articles intended to come into contact with skin. CLP Acute Tox. 3, STOT RE 1, Repr. 2 (H361d). Regulatory — European Union authority |
| United States | No specific federal restriction on DBT in consumer products. FDA permits organotin stabilisers in food-contact PVC under specified conditions. Regulatory |
| Canada | No specific consumer product restriction. Assessed under the Chemicals Management Plan. Regulatory |
| International | Not IARC classified. EU REACH Entry 20 is the primary consumer protection measure. EFSA evaluated organotin exposure from food-contact materials. WHO does not set an indoor air guideline. Regulatory |
What it is
Dibutyltin is a diorganotin compound (two butyl groups bonded to tin) used primarily as a heat stabilizer in PVC. During PVC processing at high temperatures, the polymer degrades unless stabilised — dibutyltin compounds (typically dibutyltin dilaurate or dibutyltin maleate) prevent this degradation by scavenging the hydrochloric acid released during thermal decomposition. IARC has not evaluated dibutyltin. The primary toxicological concern is immunotoxicity: DBT causes thymus atrophy and suppresses both cellular and humoral immune responses in animal studies. In humans, the immunotoxic threshold is not well established, but the EU restricted organotins in consumer articles under REACH as a precautionary measure. DBT is less acutely toxic than tributyltin but more widely distributed in consumer products.
Where it shows up in bedding
Dibutyltin is present in PVC mattress covers, PVC mattress protectors, and waterproof PVC crib mattress covers — products where PVC is used for its waterproof and wipe-clean properties. As the PVC ages, DBT can migrate to the surface and into dust. Vinyl flooring in bedrooms is another significant source of DBT in the sleep environment. Indoor dust surveys have consistently detected DBT, with concentrations higher in rooms with more PVC-containing products. For infants sleeping on PVC-covered crib mattresses, the proximity and duration of contact is particularly relevant. The EU restriction limits tin content to 0.1% by weight in articles that contact skin.
Citations
- EU REACH Annex XVII, Entry 20 — Organotin compounds restriction. Source Regulatory
- EFSA (2004). Opinion of the Scientific Panel on Contaminants in the Food Chain on organotin compounds in food. Source Regulatory
- Kannan, K. et al. (2010). Organotin compounds, including butyltins and octyltins, in house dust from Albany, New York, USA. Archives of Environmental Contamination and Toxicology, 58(4): 901-907. Source Peer-reviewed
Frequently asked questions
Is the PVC cover on my mattress releasing dibutyltin?
PVC mattress covers stabilised with dibutyltin compounds can release small amounts of DBT over time, particularly as the PVC ages. The EU restricts organotin in skin-contact articles to 0.1% tin by weight. If your mattress has a PVC cover and you sleep directly on it (without sheets), DBT transfer is possible. Using a cotton sheet over the PVC cover creates a barrier that reduces direct skin contact.
Is dibutyltin the same as tributyltin?
No. Dibutyltin (DBT) and tributyltin (TBT) are different organotin compounds. TBT (three butyl groups) is the more toxic antifouling biocide used on ship hulls — it caused widespread marine endocrine disruption and is banned under the International Convention on the Control of Harmful Anti-fouling Systems. DBT (two butyl groups) is less toxic than TBT and is used as a PVC stabiliser in consumer products. Both are immunotoxic, but at different potency levels.
Related compounds
Embr is a sleep environment company researching and addressing the chemistry of the bedroom. Research and product development in progress.
Last reviewed 2026-07-08. If you find a factual error, contact us.