Linseed oil

Linseed oil use has declined over the past several decades with increased availability of synthetic alkyd resins—which function similarly but resist yellowing.

[3] To prevent premature drying, linseed oil-based products (oil paints, putty) are stored in airtight containers.

Rags soaked with linseed oil pose fire hazard because they provide a large surface area for rapid oxidation.

[4] In 1991, One Meridian Plaza, in Philadelphia, was severely damaged in a fire, in which three firefighters perished, thought to be caused by rags soaked with linseed oil.

[citation needed] Traditional glazing putty, consisting of a paste of chalk powder and linseed oil, is a sealant for glass windows that hardens within a few weeks of application and can then be painted over.

Studies show the fatty-acid structure of linseed oil has problems cross-linking and oxidizing, frequently turning black.

[citation needed] Linseed oil is used to bind wood dust, cork particles, and related materials in the manufacture of the floor covering linoleum.

[10] Linoleum has given its name to the printmaking technique linocut, in which a relief design is cut into the smooth surface and then inked and used to print an image.

In one study, the content of alpha-linolenic acid (ALA) in whole flaxseeds did not decrease after heating the seeds to temperatures of up to 178 °C (352.4 °F) for one and a half hours.

Fresh, refrigerated and unprocessed, linseed oil is used as a nutritional supplement and is a traditional European ethnic food, highly regarded for its nutty flavor.

[13] The USFDA granted generally recognized as safe (GRAS) status for high alpha linolenic flaxseed oil.

Under these conditions, the polyunsaturated fatty esters convert to conjugated dienes, which then undergo Diels-Alder reactions, leading to crosslinking.