Could you please tell me if boiled linseed oil applied to finished wood then wiped dry with a cloth has a danger of being toxic? – Buz Brown
Michael Dresdner: Boiled linseed oil is a drying oil, which means that it will go from liquid to a solid film in a day or two after it is applied to wood. Once it is dry, it is quite safe.
As you probably know, raw linseed oil, sold as flaxseed oil in the grocery store, is edible and considered by some to be a health food supplement. To make boiled linseed oil, metal salts are added. They cause the oil to dry faster. While these render boiled linseed oil inedible, you’d have to consume a decent amount before it would be toxic. However, once the oil is dry, the metals are trapped in the film, making it perfectly safe for use on furniture.
Incidentally, the single most hazardous aspect of boiled linseed oil is fire risk. Oily rags or towels, if left in a pile, generate enough heat during cure that they can spontaneously combust, smoldering and eventually bursting into flame all by themselves. Make sure you lay your used oil wipes out one layer thick so they can dissipate that heat while drying. Once they are dry and crusty, they are landfill safe and can go out with the household trash.