Butene-1, or 1-butene, is a linear alpha olefin (alkene), produced either by separation from crude C4 refinery streams or from the reaction of ethylene. It is distilled to give a very high purity product.

Butene-1 is used in the manufacture of a variety of other chemical products. It fills an important role in the production of materials such as linear low density polyethylene (LLDPE). The co-polymerisation of ethylene and Butene-1 produces a form of polyethylene that is more flexible and more resilient.

Butene-1 can also help to create a more versatile range of polypropylene resins. It is also used in the production of polybutene, butylene oxide and in the C4 solvents secondary butyl alcohol (SBA) and methyl ethyl ketone (MEK).

Butene-1 is also used as a building block in the production of plasticizers as well as the manufacture of high performance gasoline additives.