Linseed oil

Linseed oil is a yellowish drying oil derived from the dried ripe seeds of the flax plant (Linum usitatissimum, Linaceae). It is obtained by pressing, followed by an optional stage of solvent extraction. Cold-pressed oil obtained without solvent extraction is marketed as flaxseed oil. It is suitable for human consumption (though not recommended for cooking) and is used as a nutritional supplement which is high in omega-3 fatty acids, especially alpha linolenic acid, similar to those found in fish such as salmon.

Boiled linseed oil was used a paint binder or as a wood finish on its own. Heating the oil makes it polymerize or oxidise more readily. However, today, metallic dryers are used instead of heat. The use of metallic dryers makes boiled linseed oil inedible.

Nutrient content of flax seed oil

Approximate per 100 grams (3½ ounces)

Food energy 450 calories (1,880 kilojoules)
Fat 41.0 grams
Total dietary fibre 28.0 grams
Protein 20.0 grams
Its uses include:

Animal feeds
Caulking compounds
Brake linings
Foundry products
Leather treatment
Polishes, varnishes and oil paints
Animal care products
Wood preservation
Synthetic resins
Oil painting medium
The linoleic acid in linseed oil is used as a dietary supplement.

Linseed oil has a special cultural place in cricket playing countries as treatment for the raw willow wood used to make cricket bats.

Safety Note: Rags soaked in linseed oil can self-ignite if stored in a confined space. They should be washed with water and disposed of carefully.