Treated vs. Untreated wool

Wool is wool… or is it?
There are actually big differences between the types of wool you can buy – both in terms of quality, skin-friendliness and the environment. Wool is usually divided into ’treated’ and ’untreated’ wool. This is somewhat of a misnomer, however, since, in principle, all wool is treated: the difference lies in the method used to treat it.

Treated vs. Untreated wool

Treated vs. Untreated wool


Treated wool (conventional wool)
The majority of all woolen underwear on the market is made from treated wool. With treated wool is usually meant a wool, which has gone through a treatment called ’Superwash’. With a superwash treatment, the outer scurf/scratchy hairs from the wool fiber are first removed by using a chlorine treatment. When the worst of the scurf/scratchy hairs has been removed, the wool fiber is 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 the wool, after being coated with this thin film of resin, becomes less fragile. Therefore, it is easier for the manufacturer to color, and the consumer does not need to be nearly as attentive while washing in order to avoid shrinkage and matting. Furthermore, the treatment makes the wool not scratchy.

The chlorine treatment of the wool has a negative influence on the environment, since some amount of chlorine and AOX* is released with the wastewater. Furthermore, the thin film of resin limits the natural qualities of the wool, among them the ability to absorb wetness and protect against sweat odors, since it is more difficult for the sweat to penetrate the structure of the wool (see the section about sweat absorption and protection against sweat odors).

*We have had both our conventional and organic wool tested by a third party. These tests clearly show a higher content of chlorine and AOX in the product made from conventional wool than the one made from organic. There is no documentation as to whether these substances, in this amount, are harmful to your skin. Therefore, we have sent the test results to both Asthma-Allergy Denmark and to the Danish Environmental Protection Agency, but they also have no answers about this. Wi will, however, continue our research and keep you updated if we find an answer.

Untreated wool (organic wool)
Untreated wool is the term for wool, which has not been through this environmentally damaging superwash treatment, but which has instead been treated gently with no changes to the structure of the wool.

DILLING’s organic line is an example of this. Since we do not use superwash for it, but would still like to achieve a soft quality, our organic wool instead goes through an enzyme treatment to remove scurf/scratchy hairs from the wool fiber. For the nerds out there, the specific enzyme used is an environmentally friendly enzyme, which frequently is also used in laundry detergent. The enzyme breaks down proteins by attacking peptide bonds, and in just the right process, you can go in and use the enzyme to smoothen out the wool fibers, so the wool neither scratches or tangles.

Since with an enzyme treatment, the scratchy hair is removed more efficiently than with chlorine treatment, the wool feel nicely soft – Thus, there is no need to cover the wool fiber with a film of resin. Because of this, the wool keeps its natural properties to absorb moisture, regulate body temperature, and protect against sweat odors. Furthermore, this treatment is very gentle on the environment, since no environmentally damaging chemicals are released with the waste water.

Since enzyme-treated wool is not encapsulated in a film of resin, it is more fragile in the wash than superwash-treated wool. For the consumer, this means that you need to be more careful with following care and laundry instructions for the product. With DILLING’s organic wool, however, you do not need to handwash everything – our organic products can easily handle going in the washing machine, as long as it is done on wool setting at 30° with wool detergent.

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

Temperature regulation
Wool is an excellent material for insulation: it can keep you cool when it is hot and warm when it is cold. Thus, woolen underwear can be used all year long – many, however, might want a slightly thicker version during the winter months and a thinner wool in the summer months.

Sweat absorption
Wool can naturally absorb as much as 33% of its own weight in moisture without feeling wet. This makes wool ideal for sports, both summer and winter, as it wicks away the sweat from the body, whereby your skin remains dry. This property is also attractive for baby and children’s clothing, as it enables the kids to switch back and forth between activity and rest without you needing to worry about damp clothes, which can cause them to catch a cold.

Protection against sweat odors
Perhaps you have already heard that woolen underwear protects against sweat odors – but you wondered how that can be? First of all, it is important to point out that sweat has no smell in and of itself. It is only when sweat sits on your skin that it is attacked by bacteria, causing the familiar sweat odor. When wool absorbs sweat, which is described above, it becomes bound by the wool structure. The bacteria cannot penetrate it, and therefore cannot cause the sweat to smell bad. Thus, the wool helps to prevent sweat odors, and your woolen underwear will not smell badly like things like polyester tend to do.

Many believe that wool doesn’t smell, because the wool contains traces of lanoline from the sheep. Lanoline is a type of water-resistant wax produced by the sheep. In nature, this ensures that the sheep’s wool will not get soaked, but when this wool is used for clothing, this wax is often washed out entirely.