Linseed oil: types, properties and applications

Linseed oil (flaxseed oil) is a liquid vegetable product obtained from the dried, ripened seeds of the flax plant (Linum usitatissimum). It is one of the oldest known oils, occupying a unique dual position: it is simultaneously a valuable food product rich in omega-3 acids and a critical technical raw material for the paint, printing and electrical industries. Its high content of polyunsaturated fatty acids provides both the health benefits of edible oil and the ability of technical oil to dry quickly and form a film.

Chemical Nature and Fatty Acid Composition

The basis of linseed oil is triglycerides of fatty acids. Its distinctive feature is an exceptionally high content of alpha-linolenic acid (ALA) - a polyunsaturated omega-3 fatty acid. According to reviews, linseed oil contains 50-60% linolenic acid, 14-17% linoleic (omega-6), 16-20% oleic (omega-9), 5-7% palmitic and 3-4% stearic acids. It is ALA that determines the rapid oxidation and polymerisation of the oil in air, which is critical for technical applications.

In addition to triglycerides, linseed oil contains lipophilic concomitants: tocopherols (vitamin E), phytosterols, squalene, phospholipids and cyclolinopeptides. Cold pressing preserves the maximum of these valuable components, including gamma-tocopherol and cyclolinopeptides, which have antioxidant and biological activity.

Classification, Standards and Types

In Russia and CIS countries, requirements for technical linseed oil are established by GOST 5791-81 "Technical linseed oil. Specifications". The standard applies to oil produced by pressing or extraction from oil flax seeds (according to GOST 10582) and fibre flax (according to GOST 11549). The standard normalises density, refractive index, saponification number, mass fraction of unsaponifiable substances and other physicochemical characteristics.

Edible linseed oil is produced according to separate technical specifications and standards focused on food safety. The fundamental difference between edible and technical oil lies in the degree of purification and the presence of additives: edible oil is purified and suitable for food contact, whereas technical oil and varnish may contain siccatives, impurities and additives unsuitable for food contact.

By extraction method, the following are distinguished:

• Cold Pressing - the most gentle method at temperatures below 50 °C, preserving maximum beneficial substances and yielding oil suitable for food purposes without refining.

• Hot Pressing - seeds are preheated, increasing oil yield but reducing oxidative stability.

• Solvent Extraction - an industrial method using hexane or acetone, providing maximum yield but requiring further refining.

Production Technology

Linseed oil production begins with cleaning and drying flax seeds. For edible oil, cold pressing on screw presses is preferred, yielding a high-quality product, although the oil yield is lower (about 22-41% depending on pressing parameters). For technical oil, a combination of mechanical pressing and solvent extraction is often used, which is more cost-effective for large volumes.

After pressing, the oil is settled, filtered and, if necessary, refined (for food purposes). Technical oil may undergo additional processing to produce varnish - a product of heat treatment (bodying) of the oil with the addition of siccatives to accelerate drying.

Applications

Food consumption and nutraceuticals. Linseed oil is one of the richest natural sources of omega-3. It is used as a dietary supplement, in sports nutrition and for dressing cold dishes. Due to its high ALA content, it helps lower cholesterol, improve metabolism and reduce the risk of cardiovascular diseases.

Paint and coatings industry. Technical linseed oil is a classic drying oil. Upon contact with atmospheric oxygen, it polymerises to form a durable elastic film. It is used to produce varnishes, oil paints, lacquers, wood impregnations, putties and mastics.

Printing and linoleum production. Linseed oil is traditionally used as a binder in printing inks and as a base for linoleum and oilcloth production.

Electrical engineering and other industries. The oil finds application in the electrical, leather and footwear, textile, soap-making and pharmaceutical industries.

Safety and Storage

Linseed oil requires special storage conditions due to its tendency to oxidise. Edible oil is stored in a dark, cool place in tightly closed containers, as light and heat accelerate rancidity. Technical oil and varnish are stored in airtight containers to prevent premature polymerisation.

Critical warning: rags, cloths and sawdust soaked with linseed oil pose an increased fire hazard. The oxidation of the oil is exothermic and can lead to spontaneous combustion. There are known cases of major fires caused by this very reason. Used rags must be soaked in water or disposed of in sealed metal containers.

Market and Trends

The global linseed oil market demonstrates steady growth, supported by demand for healthy food products and natural technical materials. Russia is the largest producer and exporter of flax seeds, significantly ahead of Kazakhstan and Canada.

In recent years, there has been explosive growth in flax processing within Russia. According to Oleoscope, in the 2025-2026 season, linseed oil production grew from 16 thousand to 72 thousand tonnes, and exports - from 6 thousand to 52 thousand tonnes, almost ninefold. In 2025, linseed oil exports in value terms increased 2.2 times, to USD 12 million. The largest buyer is China (USD 5.4 million), and supplies to Chile have also begun (USD 5.3 million).

Key trends include growing demand for cold-pressed and organic edible oil, the development of deep flax processing within the country, and the expansion of exports to China and the Asia-Pacific region.

Conclusion

Linseed oil remains a unique product combining nutritional value and technical functionality. Understanding the differences between edible and technical oil, knowledge of standards (GOST 5791-81), pressing technologies and polymerisation properties is the basis for competent product selection for specific purposes - from dietary nutrition to paint and varnish production.