THF (CAS #109-99-9) is a colorless, highly flammable liquid with an ether-like odor detectable at concentrations as low as 4 ppm (odor threshold).
It is mainly used in industry as a solvent for various polymers and resins, and is also used in rubber production, cellophane, adhesives, tapes and printing inks. It is also an industrial solvent for PVC and is used for degreasing varnishes and metal parts. It is a medium polar solvent that can dissolve a wide variety of nonpolar and polar compounds.how flammable is thf
THF is commonly used in polymer science, for example, to dissolve polymers prior to determining their molecular weight using gel permeation chromatography, and as a component of mobile phases in reversed-phase liquid chromatography. THF is a commonly used solvent when a moderately high boiling ethereal solvent is required and its miscibility with water is not an issue.
See also Environmental, Health and Safety (EHS) Peroxide Forming Materials SOP.
Synonyms include: divinyl oxide; 1,4-epoxybutane; tetramethylene oxide; tetrahydrofuran; oxolane.
Work Practice Controls [provide additional information relevant to your research proposal]
 Eliminate sources of ignition such as open flames, hot surfaces, steam baths, and the operation of non-intrinsically safe mechanical and electrical equipment.
Keep container tightly closed when not in use to minimize generation of flammable vapor concentrations.
Ensure proper grounding and avoid static electricity. Always ground metal containers when transferring flammable liquids.
The minimum amount required to maintain work in progress. The smallest practical quantities were used in the experiments performed.
 Never open dented or otherwise damaged THF containers.
 Wherever possible, buy THF with added inhibitors (for peroxide formation).
THF containers must be dated upon receipt and upon opening due to its peroxide formation hazard. If tested, note the date of the test.
 Periodically test THF containers with peroxide test paper.
Do not allow to evaporate to near dryness unless proven to be free of peroxide.
Consult THF's SDS to determine how long an opened container can be safely used, and dispose of unused quantities after that time period has elapsed (or if peroxide is found to be present by testing).
 Know the location of the nearest fire extinguisher before starting work.