How Fish Oils Are Used in Industry

Fish oil is one of the most versatile natural products to come out of the seafood processing industry. While most people associate it with omega-3 supplements and health food stores, the truth is that fish body oils have been powering a wide range of industries for decades – from paints and leather to lubricants and printing inks. These industrial applications are rooted in the oil’s unique chemical properties, especially its semi-drying nature, which allows it to partially harden when exposed to air while remaining flexible. Let’s explore the many ways fish oils are put to work beyond the dinner table.

What makes fish oil industrially useful? 🔗

Before diving into specific applications, it helps to understand what gives fish body oil its industrial value. Fish oil is rich in polyunsaturated fatty acids (PUFAs), including long-chain fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These unsaturated bonds are what make the oil reactive – when exposed to oxygen, the oil undergoes a process called oxidative polymerisation, forming a tough, flexible film.

This behaviour classifies fish oil as a semi-drying oil. Unlike fully drying oils (like linseed oil) that harden completely, or non-drying oils (like olive oil) that stay liquid, semi-drying oils strike a middle ground. They form a pliable, water-resistant coating – a property that is highly prized in several manufacturing processes. According to a report by the U.S. Bureau of Commercial Fisheries, the high degree of unsaturation combined with a unique mix of fatty acid chain lengths is what makes fish oils especially competitive in the industrial oil market.

The major fish species used for industrial oil extraction include anchovy, menhaden, herring, and pilchard. The oil is typically obtained as a by-product during fish meal manufacturing – cooked fish are pressed to release a liquid mixture of oil and water, which is then separated using centrifuges.

Fish oil in paints and varnishes 🔗

One of the oldest and most significant industrial uses of fish body oil is in the production of paints, varnishes, and protective coatings. The semi-drying property of fish oil means that when it is applied to a surface, it gradually forms a durable, elastic film that resists moisture and weathering.

Fish oil has historically served as a cost-effective alternative to linseed oil in coating formulations. A study published in the Journal of Cultural Heritage documented that American paint manufacturers in the 19th and 20th centuries routinely used menhaden fish oil in house paints – often blending it with vegetable oils. Fish oil was cheaper than linseed oil, so manufacturers frequently incorporated it without advertising its presence.

Fish oil-based coatings are particularly valued for marine applications. Boats, docks, and other waterfront structures need protection against constant saltwater exposure. Fish oil coatings don’t become brittle over time the way some plant-based oil films do, making them especially suitable for these harsh environments. The oil’s natural ability to penetrate wood fibres also makes it effective in wood stains and preservatives used for outdoor structures.

How fish oil competes with other drying oils 🔗

In the protective coatings industry, fish oils compete with linseed, soybean, castor, tung, and tall oils. As noted in the U.S. Bureau of Commercial Fisheries report, fish oil’s relatively low cost compared to most other drying oils – along with its high unsaturation – gives it a distinct market advantage. Only tall oil was historically cheaper. This price factor has made fish oil a go-to option for manufacturers looking to keep production costs down while maintaining coating performance.

Fish oil in the leather industry 🔗

Leather tanning is another area where fish oil has played a crucial role for centuries. Oil tanning – also called chamois tanning – is one of the oldest methods of converting raw animal hides into soft, usable leather. According to Encyclopaedia Britannica, the three most widely used tanning agents in the world are vegetable tannin, chromium salts, and fish or animal oil.

In this process, fish oil is applied to the hide – either by hand or using a mechanical drum – and worked into the skin until it replaces the natural moisture. The oil then oxidises and binds to the collagen fibres, stabilising them against decay and making the leather soft and flexible.

Properties of oil-tanned leather 🔗

The leather produced through fish oil tanning is called chamois leather. It has several distinctive properties that set it apart from chrome-tanned or vegetable-tanned leather. Chamois leather is exceptionally soft and porous. It has outstanding water absorption capacity, which is why it is widely used for cleaning and drying applications – from automotive detailing to optical lens care. Additionally, chamois leather can be repeatedly wetted and dried without suffering damage, unlike many other leather types.

The fish oil tanning process also gives leather good breathability. This makes it suitable for garments, orthopaedic products, and filtration materials. While chrome tanning dominates the modern leather industry (about 80% of all leather globally), oil tanning remains important for these specialised products.

Fish oil in printing inks 🔗

The printing ink industry has long relied on drying and semi-drying oils as key ingredients in ink formulations. Fish oil serves as a useful component in this sector because of its ability to act as a binder and drying agent.

In traditional offset printing, the ink needs an oil-based vehicle that can dissolve pigments and resins, provide the right viscosity for application, and then dry to form a stable film on paper. Fish oil, with its semi-drying characteristics, can fulfil these functions. Historically, fats and oils – including fish oils – were the primary raw material source for paints, coatings, and printing ink applications before petroleum-based products took over in the mid-20th century.

Today, the push for environmentally friendly printing has renewed interest in bio-based oils for ink manufacture. Fish oil, along with soybean and linseed oils, is being revisited as a greener alternative to petroleum-derived ink solvents. These bio-based inks release fewer volatile organic compounds (VOCs) and are more biodegradable.

Fish oil as lubricants and greases 🔗

Fish oils are also employed in the manufacture of lubricants and greases. Their unique fatty acid composition – including a broad range of chain lengths and high levels of unsaturation – gives them lubrication properties that are useful in specific industrial contexts.

The U.S. Bureau of Commercial Fisheries identified lubricants, greases, and buffing agents as major non-food applications of fish oil. The oil’s ability to reduce friction between surfaces while maintaining a stable film under moderate temperatures makes it suitable for certain machinery applications.

Bio-lubricants from fish oil waste 🔗

In recent years, researchers have explored the possibility of converting fish oil waste into bio-lubricants through chemical processes like transesterification. A study published in the Journal of Cleaner Production investigated producing bio-lubricants from fish oil residue using trimethylolpropane. The resulting products showed good lubrication properties – including favourable viscosity, pour point, and oxidative stability – making them viable alternatives to petroleum-based lubricants.

This is significant because the global lubricant industry is massive, and conventional mineral lubricants pose serious environmental risks when they leak or are disposed of improperly. Bio-lubricants from fish processing waste offer a sustainable and circular economy approach – turning a low-value by-product into a high-performance industrial material.

Fish oil as insecticides and pest control agents 🔗

Fish oil has also found use as a component in insecticidal formulations. When processed into an emulsifiable concentrate or spray, fish oil can act as a contact insecticide and a suffocant – it physically coats and smothers soft-bodied insects and their eggs.

This application is particularly relevant in organic and sustainable agriculture, where synthetic chemical pesticides are restricted. Fish oil-based sprays are used against aphids, mites, scale insects, and other pests on fruit trees and vegetables. The oil works by blocking the insect’s respiratory system and disrupting its cell membranes. Since fish oil is a natural, biodegradable substance, it breaks down quickly in the environment and does not leave harmful residues on crops.

Some commercial horticultural oil sprays also incorporate fish oil as a component because of its spreading and adhesion properties, which help the spray coat plant surfaces more evenly.

Protective coatings for boats and marine structures 🔗

Given that fish oil originates from the sea, it is fitting that one of its most enduring industrial uses is in protecting marine vessels and structures. Fish oil-based coatings are applied to the hulls of boats, fishing vessels, docks, and pilings to guard against corrosion, water damage, and biological fouling.

The U.S. Department of the Interior noted that protective coatings on wood, metal, fibre, and concrete are among the primary industrial uses of fish oil. The oil’s ability to penetrate porous surfaces and form a resilient, water-resistant film makes it well-suited for structures that are constantly exposed to moisture and salt.

Modern marine coatings may combine fish oil with synthetic polymers and anti-fouling agents to enhance performance. But the fundamental principle remains the same – the oil polymerises upon exposure to air, creating a protective barrier.

Other industrial applications 🔗

Beyond the major uses discussed above, fish body oils serve several additional industrial purposes:

Soap manufacturing: Fish oil was once a common ingredient in soap production. While its share has declined dramatically – in the UK, fish oil accounted for only about 0.3% of total fatty raw materials used in soap – it still finds niche use in certain industrial soap formulations.

Rubber production: Fish oil is used in the manufacture of rubber and synthetic wax. The oil’s chemical reactivity allows it to participate in vulcanisation-related processes and serve as a processing aid.

Biodiesel: With growing interest in renewable energy, fish oil waste from processing plants is increasingly being converted into biodiesel through transesterification. The European Union alone generates approximately 5.2 million tonnes of non-edible fish waste per year, much of which could be used for biofuel production.

Caulking compounds and water repellents: Fish oil’s water-resistant film-forming ability makes it useful in caulking formulations for sealing joints and gaps, as well as in water-repellent treatments for textiles and other materials.

The bigger picture: sustainability and value addition 🔗

What makes the industrial use of fish oil particularly compelling is its role in the broader story of waste valorisation in the seafood industry. Most commercial fish oil is extracted not from whole fish harvested specifically for this purpose, but from the by-products and trimmings generated during fish processing for human consumption. Heads, viscera, tails, and other discards that would otherwise go to waste are instead converted into a valuable industrial raw material.

This approach aligns with the principles of the circular economy – minimising waste, maximising resource utilisation, and creating economic value at every stage of production. For fishing communities and processing companies, industrial fish oil represents an important additional revenue stream that improves the overall economics of fish harvesting.

As environmental regulations tighten and industries seek greener alternatives to petroleum-based products, the demand for bio-based oils – including fish oil – is expected to grow. Advances in refining and chemical modification are continually expanding the range of products that can be derived from fish oil, from high-performance bio-lubricants to eco-friendly coatings and inks.

What do you think? Given the wide range of industrial applications of fish oil, could expanding these uses help reduce the seafood industry’s waste problem while also cutting dependence on petroleum-based alternatives? How might the economics of fish oil production change as global demand for sustainable industrial materials increases?

References

1. https://spo.nmfs.noaa.gov/sites/default/files/legacy-pdfs/CIRC278.pdf
2. https://www.britannica.com/science/fish-oil
3. https://www.sciencedirect.com/science/article/abs/pii/S1296207421000959
4. https://www.britannica.com/technology/tanning
5. https://www.sciencedirect.com/science/article/abs/pii/S0959652622013683
6. https://pubmed.ncbi.nlm.nih.gov/17992002/
7. https://www.sciencedirect.com/science/article/abs/pii/S0959652618322492
8. https://pmc.ncbi.nlm.nih.gov/articles/PMC6517906/