I found this on a google search......
Linseed oil is available in two forms: raw and boiled. Raw linseed oil is practically non-toxic, but boiled linseed oil should be avoided because certain additives may be toxic to the liver. Linseed oil may cause moderate skin irritation and gloves should be worn to avoid skin exposure.
Published research regarding the environmental effects of linseed seed oil is not available. However, anecdotal information from those that have used linseed oil over the years indicate that it is very effective. Rags soaked with linseed oil are extremely flammable and should be rinsed in water and air dried thoroughly before being thrown in the trash.