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Treated vs. Untreated wool

Wool is wool… or is it?
There are actually some major differences between the types of wool you can buy- in terms of quality, as well as how skin and environmentally friendly it is. Wool is usually separated by ‘treated’ and ‘untreated’ wool, however this is somewhat of a misnomer, as all wool is treated. The difference lies in the method of treatment.

Treated vs. Untreated wool

Treated vs. Untreated wool


Treated wool (conventional wool)
The majority of woollen underwear on the market is made from wool that has been treated. This usually means it has undergone a treatment called ‘Superwash’, which removes the outer scratchy hairs from the wool fibres using a chlorine treatment. Once the worst of the itchy hairs have been removed, the wool fibres are then covered in a thin film of either natural or artificial resin (tree resin or some form of plastic).

The wool becomes easier to handle, both for the manufacturer and the consumer. This is because after the wool has been covered with this thin film of resin, it becomes less fragile. As a result, it becomes easier to dye and the consumer doesn’t have to be as careful when washing the clothes to avoid shrinkage or matting. Additionally, the chlorine treatment makes the wool soft and non-itchy.

Chlorine treatment has a negative influence on the environment, as the amount of chlorine and AOX* released in the wastewater is significant. The thin film of resin also limits the natural qualities of the wool, including the wool’s ability to absorb wetness and protect against sweat odours as it is more difficult for the sweat to penetrate through the wools structure (see section on sweat absorption and protection against sweat odours).

*We have had both our conventional and organic wool tested by a third party. These tests show a higher level of chlorine and AOX in the conventional wool products compared to the organic ones. There is no evidence as to whether these substances are harmful to your skin, therefore we have sent the test results to both Asthma-Allergy Denmark and the Danish Environmental Protection Agency, but they also have no answers. However, we will continue our research and keep you updated if we find an answer.

Untreated wool (organic wool)
Untreated wool refers to wool which has not been through the environmentally damaging “Superwash” treatment but has instead been treated gently without changing the structure of the wool.

DILLING’s organic range is an example of untreated wool. Although we don’t use Superwash, we still want to achieve a soft quality. Therefore, our wool undergoes an enzyme treatment to remove any itchy hairs from the wool fibres. However, the enzyme we use is an environmentally friendly enzyme also used in laundry detergent. The enzyme works by attacking peptide bonds to break down proteins, which at the same time allows you to use the enzyme to smoothen the wool fibres so they aren’t itchy.

Using an enzyme treatment means itchy hairs can be removed more efficiently than with a chlorine treatment. This is because the wool is left feeling nicely soft without needing to cover the wool fibre with a film of resin. As a result, the wool keeps its natural moisture-absorbing and temperature-regulating properties as well protecting against sweat odours. Additionally, this treatment process is incredibly gentle on the environment as no environmentally damaging chemicals are released with the water waste.

Because enzyme-treated wool has not been encapsulated in a film of resin, it is more fragile when washing than Superwash-treated wool. For you, the consumer, this means you need to be more careful when following the care and laundry instructions for the product. However, with DILLING’s organic wool, you do not need to hand wash everything; they can easily go in the washing machine as long as it is done on a 30o wool setting with wool detergent.

Natural properties of wool
Both treated and untreated wool have some good, natural properties, but as shown in the illustration, these are best maintained with treatments where the wool is not encapsulated in a film of resin.

Temperature regulation
Wool has excellent insulating properties and will keep you warm when it’s cold and cool when it’s hot. Therefore, woollen underwear can be worn all year round, however many want a thicker wool in the winter and a thinner wool in the warmer months.

Sweat absorption
Wool can naturally absorb up to 33% of its own weight in moisture without feeling wet, making it ideal for sports all-year round as it wicks sweat away from the body, keeping your skin dry. This property is also perfect for babies and children’s clothing, as they can switch between rest and play without you worrying about them getting damp clothes or catching a cold.

Protection against sweat odors
Perhaps you’ve heard that woollen underwear can protect against sweat odours, but how is this? Firstly, it is important to note that sweat has no smell itself. It is only when the sweat on your skin is attacked by bacteria, that the familiar sweat odour protrudes. When wool absorbs sweat, it becomes bound by the wool structure and the bacteria cannot penetrate it, therefore no bad sweat smell lingers. Ultimately, the wool helps prevent sweat odours and unlike polyester clothing, your woollen underwear will not small badly.

Many believe wool doesn’t smell because of the traces of lanoline it contains from the sheep. Lanoline is a water-resistant wax sheep produce. In nature, this prevents the wool of the sheep getting soaked, but when wool is used for clothing, this wax is often entirely washed out.