Walnut shells are a by-product of walnut processing, but instead of going to waste, they are instrumental in a vast number of industries ranging from the cosmetics industry to the oil industry to the pet industry! Walnut shells are non-toxic, biodegradable and reusable too, making them a popular material to work with. Here are a few of the ways that walnut shells are utilised across the globe.

Oil Industry

In the oil industry, lost circulation, described as the total or partial loss of drilling fluids or cement to cavernous formations, high-permeability zones, or natural/induced fractures, can be a serious problem during the drilling of an oil well or gas well. Walnut shells are widely utilised as a lost circulation material to combat these problems associated with the drilling of wells. It is incredibly efficient and an easy solution to lost circulation. Walnut shell can also be used as an environmentally safe and effective filtration media when separating crude oil from water.


Walnut shells are widely used to polish and clean materials such as metal, glass, and plastics. They can be used on delicate parts of machinery without scratching, marking, or etching the cleaned areas. Fine metals, alloys, eye glasses, coral, and shell cartridges are amongst the many products that benefit from being polished using walnut shells. You can even make your own walnut shell polish to use around the house on jewellery or other metal objects. To do this, finely crush the walnut shells in a grinder, and sift through a sieve or tea strainer. Mix the powder with soap or soft beeswax and that’s it – you have your own homemade walnut shell polish!

Pet Products

As an all-natural, dust free, biodegradable product, walnut shell provides safe bedding for reptiles, birds, and small animals it is very easy to dispose of and can also be composted. Ground walnut shells are commonly used in pet litters for cats, birds, and reptiles – they are biodegradable and in turn, environmentally friendly. Walnut shells can also be found in some livestock feed.

Cosmetic Industry

Even the cosmetic industry has found a use for the versatile walnut shell! Walnut shell medium is a popular ingredient in exfoliants used on the face and body and in foot scrubs. It is widely used by those in the industry, ranging from the start up home-made soap maker to multinational commercially distributed cosmetic companies.


Walnut shells have proven to be an excellent type of blast media, used for cleaning an array of materials including metals, woods, stone, plastic, and fibreglass. The shells can be ground down to any size required, from extra fine to coarse, depending on the requirements and can be used in the same way as more traditional blast media. The shells are extremely durable and can be used repeatedly and can remove unwanted matter from surfaces without causing any pitting or scratches.

Fillers, Extenders and Anti-slip Media

Many applications used as a filler of extender can contain walnut shells and walnut flour – these applications can include resins, pigments, adhesives, plywood, paint, coating materials and even dynamite! Non-skid and anti-slip media can also include walnut shells. These media types can be mixed-in to paints for easy usage. Anti-slip materials are widely used on ramps, decks, swimming pools, tubs, surfboards, and skate boards.

Water Filtration

Nutshell filtration is deemed the next generation in technology. With environmental regulations changing rapidly, manufacturers around the globe are being asked to meet much more stringent water quality standards and this is where walnut shells come in. Walnut shells are used in filtration systems to remove grease and oil as well as filtering suspended solids from a variety of refinery, chemical plant, and oilfield water systems. What makes this technology so special is that it can be as efficient as 99% in the removal of oils and solids, which is unattainable by many other kinds of removal technology.


As you can see, walnut shells can appear in any number of settings, from hand soap to industrial technology, so next time you wash your hands, or put on your polished necklace, or clear out your pet’s litter tray, have a think about whether the humble walnut shell played its part in creating the finished product.

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