At a glance
| Chemical family | Organophosphate — trialkyl phosphate ester (flame retardant, plasticizer, solvent) |
| CAS number | 126-73-8 |
| Classification | Not classified by IARC. EPA classified as Group D (not classifiable as to human carcinogenicity). Primary concern is cholinesterase inhibition at high doses and irritation |
| Where you encounter it | Polyurethane foam; floor coatings and polishes; hydraulic fluids; nuclear fuel reprocessing solvent; house dust (ubiquitous) |
| Sleep micro-environment relevance | Found in house dust across multiple continents. Less studied than other OPFRs but ubiquitous in indoor environments. Contributes to cumulative organophosphate dust exposure during sleep |
Regulatory & certification status
| European Union | REACH registered substance. Not on the SVHC candidate list. CLP classification includes Eye Dam. 1 (H318), Acute Tox. 4 (H302, oral). Regulatory |
| United States | EPA classified as Group D (not classifiable). Listed under TSCA inventory. Included in EPA OPFR Action Plan for further assessment. Regulatory |
| Canada | Under assessment as part of the Chemicals Management Plan organophosphate FR grouping. Regulatory |
| International | Not IARC classified. Not a Stockholm Convention POP. Ubiquitous in indoor dust globally but at concentrations below health-based concern levels. Regulatory |
What it is
Tributyl phosphate is the triester of phosphoric acid with n-butanol. It is a versatile organophosphate compound used in several industries: as a flame retardant and plasticizer in polymers, as a defoaming agent, as an extraction solvent in the nuclear industry (PUREX process for uranium/plutonium separation), and as a component of hydraulic fluids and floor polish. TBP is a liquid at room temperature and is semi-volatile, which contributes to its widespread detection in indoor air and dust. It is not classified as a carcinogen by IARC or other major agencies. At high occupational exposures, TBP can inhibit cholinesterase and cause respiratory and skin irritation, but at the trace levels found in household dust, these effects are not expected.
Where it shows up in bedding
TBP enters the bedroom through multiple diffuse sources: it is a component of some polyurethane foam formulations, floor polishes and coatings, and consumer electronics. Its semi-volatile nature means it partitions between air and dust in indoor environments. House dust surveys in North America, Europe, and Asia consistently detect TBP, though usually at concentrations below those of TCPP and TPHP. During sleep, exposure occurs through dust ingestion and inhalation. TBP is not typically a major contributor to any single bedroom exposure pathway, but it adds to the cumulative organophosphate FR burden in indoor dust.
Citations
- Van den Eede, N. et al. (2011). Organophosphate flame retardant and plasticiser concentrations in dust from electronic equipment and mattresses. Environment International, 37(3): 517-523. Source Peer-reviewed
- EPA. Flame Retardants Used in Flexible Polyurethane Foam — Alternatives Assessment. Source Regulatory
- ECHA. Tributyl phosphate — Substance Information. Source Regulatory
Frequently asked questions
Is tributyl phosphate dangerous in house dust?
At the trace concentrations typically found in household dust, tributyl phosphate is not expected to cause health effects. TBP can inhibit cholinesterase and cause irritation at high occupational exposures, but residential dust levels are orders of magnitude below these thresholds. TBP contributes to the cumulative organophosphate FR burden in indoor environments.
Why is TBP so widely detected indoors?
TBP is used in a wide range of products — polyurethane foam, floor coatings, electronics, hydraulic fluids — and is semi-volatile, meaning it migrates from products into air and dust over time. Its diverse source profile and physicochemical properties make it one of the most frequently detected organophosphate esters in indoor dust surveys globally.
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.