Is Wool Biodegradable? (And Is It Compostable?)

Humans have been known to domesticate animals for thousands of years. They include cattle, camels, chickens, donkeys, horses, goats, pigs and sheep, among many others. Sheep, in particular, are domesticated for their meat, milk and akin and are in fact among the first animals to be domesticated by humans.

The sheepskin is mainly harvested and made into wool, a natural fiber used to make some of the world’s highest quality apparel and high-end fashion garments. They can also make carpets, upholstery and furnishings. It is therefore important to understand the environmental effects of wool and this article will explain these and related questions.

Is Wool Biodegradable or Nonbiodegradable?

Oh, yes, wool is biodegradable. it is a natural and renewable resource and as long as there is grass to eat, sheep will continue to produce wool. When wool is disposed of, it will naturally decompose, slowly releasing valuable nutrients back into the earth.

All materials of animal and vegetable origin have some degree of biodegradability, meaning that they are capable of being decomposed by the action of living organisms, such as fungi and bacteria.

Wool is composed of the natural protein keratin, which is similar to the protein that makes up human hair. When keratin is broken down naturally by microorganisms, the products do not pose any environmental hazard.

Wool best biodegrades in warm and moist conditions. On disposal, and if kept warm and moist or buried under the soil, fungal and bacterial growths develop which produce enzymes that digest wool.

On the other hand, and thanks to the unique chemical structure of keratin and wool’s tough, water-repellent outer membrane, clean and dry wool fibers do not readily degrade. This, therefore, allows wool products to be resilient and long-lasting in normal conditions and not biodegrade while worn.

Keratin is a member of a group of structural proteins that form the basis for hair, fur, feathers, scales and claws of mammals, birds, fish, reptiles and amphibians.

You should, however, be cautious around synthetic wool or synthetic fibers. They can be extremely slow to degrade and significantly contribute to the world’s overflowing landfills.

Another concern with regards to the biodegradability of wool is the fact that it will most certainly come from a dead animal. This results in animal cruelty or using animals to make products or fibers.

It also means harvesting it from many sheep and the more the sheep, the higher the amount of methane released into the atmosphere. methane is believed to be worse than carbon dioxide with regards to global warming, and investing in the wool business means contributing towards destroying the environment.

Although wool is natural, biodegradable and renewable, it comes at the expense of the sheep themselves, the environment and much more.

How Long Does it Take for Wool to Biodegrade?

Ideally, wool should biodegrade readily in as little as 3 to 4 months. However, the rate may vary depending on the soil, climate and wools’ characteristics. When it biodegrades, essential elements such as sulfur, magnesium and nitrogen are released back into the soil and are taken up by growing plants.

Some studies have found wool rapidly degrading only after about 4 weeks after being buried in the soil. Others argue that with the ideal conditions, wool can biodegrade in about 6 months. These conditions are warm, damp soil conditions, combined with access to oxygen.

The biodegradation process starts with naturally occurring fungi that start weakening the wool fiber. Afterward, bacteria eat up the fiber. With the right conditions, wool will biodegrade in around six months.

Results from another study have shown that within 90 days, wool can biodegrade by as much as 20% in seawater. If these results are true, then mathematically speaking, the wool will completely biodegrade in 450 days, which is 15 months.

So far, there are no answers as to how wool would biodegrade under other conditions but this should be resolved soon. The duration for the biodegradation of wool also depends on whether the product being subjected to biodegradation was made using 100% wool or was blended with other materials and whether those materials are organic or not.

If they are organic, like cotton, the degradation process will be over in a matter of months. However, if they are not, probably blended with synthetics like polyester, the degradation process will take longer.

Also, if the amount of wool is small and the synthetic fabric is too much, the entire thing will take forever to biodegrade. Nature has no corresponding microorganisms to break down these products, explaining why plastics do not biodegrade, and if they do, they will take forever

Is Wool Environmentally Friendly?

Yes, wool is environmentally friendly. It is a renewable resource and the manufacturing process causes little to no harm to the environment. It also comes from a naturally occurring animal, sheep.

Wool is acquired through the shearing of sheep, or from the skin of one after they are dead or slaughtered. Shearing sheep is just like getting a haircut as the wool grows right back, making wool completely renewable.

The only problem with wool comes from the fact that sheep are second only to cattle in the production of methane from domesticated animals. Methane is a greenhouse gas and is 28 times more harmful to the environment than carbon dioxide at warming the planet.

With sheep contributing to the destruction of the environment, it, therefore, calls to the environmental-friendliness of wool. Additionally, some wool might be dyes used on wool, which might make it less friendly to the environment. Nonetheless, with pure wool, it will be completely safe for our surroundings.

Is Wool Compostable?

Oh, yes! Wool is completely compostable and can be a great addition to your soil. Composting reduces waste and converts it into reusable soil and wool is a contender for the same, especially when you have excess wool, or sheared wool and have nowhere to take it.

Wool compost is especially useful in gardening, as it can retain water while releasing nutrients to feed plants. If your wool is pure wool with no synthetic materials, it can be composted in moderate amounts.

You can also compost your clothes similarly made from wool. Just ensure your wool does not contain dangerous dyes and other chemicals since they will leech into the soil and cause havoc there. Also, ensure there are no synthetic fibers there as they do not decompose.

To successfully compost wool, add small amounts of the wool to your compost bin. Ensure the pieces are cut into tiny pieces for quicker composting. Next, add some fruit and vegetable waste to the same bin. You can also add dry and fresh leaves and grass.

Be cautious about adding bones, meat oils and other cooked food because even though they will decompose, they will cause odors and attract vermin and pests. Adding these other scraps is important as it helps balance the necessary ratio between carbon and nitrogen inside the composting bin.

Where the ratio is balanced improperly, the necessary bacteria and fungi will not be in their ideal environment and your compost will not work. The dry leaves are a source of carbon while the fresh grass, manure and vegetable scraps will provide nitrogen.

You can also add earthworms to the mix and they will help with the decomposition process, breaking the contents into compost. The worms will also be easier for the bacteria and fungi to digest, helping them multiply more quickly and subsequently generate more heat for a quicker compost.

Try and keep your compost at a warm to hot temperature so that the process goes on smoothly. Just do not overheat it to a point of killing the beneficial microorganisms. The temperatures inside ought to be higher than those outside.

Next, make sure you aerate your compost pile by turning it severally. The best and easiest way to do this is by using a composting tumbler, which will be easy to turn. Aerating is especially important when composting wool since the material emits methyl sulfides and other offensive compounds when breaking down.

Turning your compost will also regulate temperature levels. Also, squeeze your compost to assess its moisture levels; it should be at its optimum level for healthy compost.

If the pile is too dry, it will emit odors, slowing the decomposition process, and if it is too wet, it will be too soggy to work. For the former, add some water and for the latter, turn it with a shovel or add dry materials such as leaves.

Is Wool or Polyester Better For the Environment?

Definitely! Wool is better than polyester in more ways than one, especially from an environmentalist point of view. However, the true answer to this question is dependent on the circumstance upon which you intend to use the fabric.

For instance, for high-intensity activities like running, avoid wool and go for polyester. Regardless, here is how the two fair with regards to the environment:

1. How they are made?

Wool is better for the environment based on how it is made as compared to polyester. Polyester is technically polyethylene terephthalate or PET plastic molded into filaments that are then woven into fabric.

It is made in a chemical reaction of ethylene glycol and terephthalic acid, and these chemicals are derived from fossil fuels, air, and water. These chemicals are harmful to the environment and relying on fossil fuels continues to deplete their resources as well as harm the environment.

The wool comes from sheep, naturally occurring animals that are available all over the world. It is, therefore, the environmentally-conscious option

2. Recycling

Wool again gets a point because it can be recycled. Polyester cannot be recycled using modern technology. Although new technologies will come up and help recycle polyester, that will be in the future, and the environment requires our attention now. Pure wool and cotton products are valuable as they can be mechanically recycled.

The issue comes in when you have a blend of wool and polyester, which although can be recycled if you add more than 5% polyester to the fabric, it becomes trash and will not be recyclable. Wool, therefore, encourages recycling while polyester encourages fashion overproduction and waste

3. Biodegradability

As we have established, wool is biodegradable, making it both recyclable and compostable. It can decompose in a few weeks to months, while polyester takes hundreds of years to break down.

Before that happens, however, it will degrade into little microfibers. These microfibers slough off certain types of clothes into the air when we are wearing them, and flow into our waterways from our washing machines. Therefore, points for wool!

4. Sustainability

Well, polyester is more durable than wool, making it better in that regard. However, wool is sustainably and renewably found in sheep. Polyester has to be chemically manufactured, making it unsustainable.

Additionally, wool needs to be washed less due to its antimicrobial properties, making it environmentally conscious. For these reasons, wool wins and is the better option for the environment.


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About Rinkesh

A true environmentalist by heart ❤️. Founded Conserve Energy Future with the sole motto of providing helpful information related to our rapidly depleting environment. Unless you strongly believe in Elon Musk‘s idea of making Mars as another habitable planet, do remember that there really is no 'Planet B' in this whole universe.