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Your wool underwear:

Are they really just wool?

The biodegradability of wool gets questioned more and more often. The reason for this is how the wool is treated and processed during it's journey from the sheep's back to the clothes on your body. To avoid shrinking when washed, the wool must be given a treatment. The most common treatment involves covering the wool in a thin layer of plastic. This treatment is often called superwash.

Your wool underwear:

Are they really just wool?

The biodegradability of wool gets questioned more and more often. The reason for this is how the wool is treated and processed during it's journey from the sheep's back to the clothes on your body. To avoid shrinking when washed, the wool must be given a treatment. The most common treatment involves covering the wool in a thin layer of plastic. This treatment is often called superwash.

SUPERWASH

Superwash is a treatment where the wool is basically coated in plastic, so that the fibers shrink less when washed. This has been considered a positive thing for a long time, a sign of quality. Today we know that microplastic (and in this case nanoplastic) is a big threat to the planet's vulnerable ecosystems. Research on superwash-treated wool and the damages it casues the environment are still at an early stage, but everything indicates that the microplastic that goes down the drain has a negative effect on marine life.

Superwash is just one of the problems when it comes to treating wool. In the process of dyeing and washing the wool, manufacturers can either choose cheap, environmentally harmful chemicals, or the opposite. 

Besides the environmental aspects of these treatments, there is also reason to question how the wool's natural characteristics change when treated. Smell and isolation ability are often mentioned as downsides to treated wool. 

What can you do?
For the most part, it's hard to find out how your wool is treated (with untreated wool being the exception). So, 1. ask about this when you buy wool. Not just wool underwear, but all wool products. Use your power as a consumer to show that this is important to you. 2. Choose products that are untreated or organic. 3.Learn more and become a modern consumer with knowledge about the products you use!

We know that this just makes it even more complicated to buy the "right" products. The good news is that we see that the industry improves when they see that consumers care.

Superwash is a treatment where the wool fiber is basically coated in plastic, so that the fibers shrink less when washed. This has been considered a positive thing for a long time, a sign of quality. Today we know that microplastic (and in this case nanoplastic) is a big threat to the planet's vulnerable ecosystems. Research on superwash-treated wool and damages it casues to the environment are still at an early stage, but everything indicates that the microplastic that goes down the drain has a negative effect on marine life.

Superwash is just one of the problems when it comes to treating wool. In the process of dyeing and washing the wool, manufacturers can either choose cheap, environmentally harmful chemicals, or the opposite.

Besides the environmental aspects of these treatments, there is also reason to question how the wool's natural characteristics change when treated. Smell and isolation ability are often mentioned as downsides to treated wool. 

What can you do?
For the most part, it's hard to find out how your wool is treated (with untreated wool being the exception). So, 1. ask about this when you buy wool. Not just wool underwear, but all wool products. Use your power as a consumer to show that this is important to you. 2. Choose products that are untreated or organic. 3.Learn more and become a modern consumer with knowledge about the products you use!

We know that this just makes it even more complicated to buy the "right" products. The good news is that we see that the industry improves when they see that consumers care.

What does Northern Playgroud do?

Luckily, there are alternative treatments for wool. In Northern Playground's Organic Collection, the wool is treated with Naturetexx Plasma. This is a process where air and elctiricity are used to achieve the same anti-shrink effect. It's a more expensive treatment, but the final result is that the wool acually is a complete product of nature, as well as the treatment process needing less energy. The German company Südwolle is behind the technology for this process.
Read more here

Because of cost and availability, only our Organic Collection is treated with Naturetexx Plasma. We hope in the future to be able to use this treatment on all of our products.

If you want more information on the topic, read the report below. Written by Kjersti Kviseth from 2025 Design, with input from Dr. Paul Swan from Australian Wool Innovation.

Anti felting (Easy Care)

By: Kjersti Kviseth and Dr. Paul Swan

Questions are arising related to the true biodegradability of wool, how wool sheds microfibres, and how anti felting treatment affect biodegradation, specifically in marine environments.

Superwash
Most wool actually is coated in plastic, in nano-thickness layers provided by the Hercosett Superwash treatment. This is not compliant with the natural picture we are communicating about wool.

As Dr. Paul Swan puts it; There is an emerging issue on the links between micro- and nano-plastic pollution in terrestrial and marine environments, and health impacts in ecosystems (including human health impacts) - such links could prove damaging to wool's hard-won reputation as a healthy choice.

600 tonnes of polymer is applied to wool each year for machine wash purpose, 76% of this is Chlorine-Hercosett, where the Hercosett (polyamide-epichlorohydrin) component includes chemistry of known human and eco-toxicity effect (epichlorohydrin). Given the polymers are applied as a thin layer (microns thick), the residues could well pose micro-fibre or indeed nanoparticle risks.

According to Roy Kettlewell, a specialist in the wool chemistry field, Hercosett process stops the degraded proteins on the fibre surface from being washed away during laundry. The degraded proteins swell and help stop the scales from getting close enough to interact and lead to felting. Most of the alternatives to Hercosett rely on inter-fibre bonding to impart shrink-resistance, and this mechanism is not compatible with top processing because of subsequent gilling and combing operations.
Hercosett is classed as BAT [best available technology] in Europe, because it can consistently meet the required standards of washability on all types of wool product. This is a customer requirement and expectation that may be very challenging to change.

Polysiloxane coating
The most widely used alternative to Superwash. A reduction in volume of polymer applied per kg, (0.15% solids vs 1.5-2.0% solids for Hercosett) and a much lower toxicity risk. Process time and cost are its disadvantage.

Mercerisation
The mercerised merino process used to be the most common approach to machine washable wool for many top processors and spinners because it also improved handle for next to skin products. The mercerised merino process is slower and does weaken the fibre slightly, and the overall cost of yarn is 5 to 10% higher than chlorine Hercosett treated yarn. The mercerised merino process uses 2 to 3 times as much chlorine, thus AOX generation is significantly higher and an issue of concern.

Lanazym by Dr.Petry
In the 90`s Dr.Petry developed an enzyme based process that complied with Cradle to Cradle principles. This process is less effective in terms of felting than Superwash, and difficult to control during the processing.

EXP by Schöller
A process from the Schoeller Spinning Group that enables the wool to remain machine-washable without the use of chlorine. EXP employs natural salts as an oxidizing agent, as well as an “ecological” polymer for micro patches on the yarn surface. Certified Blue Sign, Ökotex and GOTS.

NaturtexxPlasma by Südwolle
Naturetexx® Plasma is using electricity and air to provide the anti felting effect.  The effect is slightly lower than for Superwash. The plasma treatment modifies the surface of the individual wool fibres altering the scales on the fibre surface that cause felting.
It also creates energy savings in the downstream dyeing process. Waterborne dyes are taken up more quickly, and penetrate into the fibre more easily, meaning that the dyeing process can be shortened and less energy is required as a consequence.
The electricity used comes from renewable energy sources. Certified for organic use by GOTS and IVN Best, as well as Bluesign® and OEKO-TEX®.

ENVIRONMENTAL IMPACT

All manufacturers know that a product has an impact on the environment. We must realize that we are affecting the environment in our production of Zipwear, just as you must realize that you as a consumer have an impact in the same way.

We are taking action to minimize our environmental impact.

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