Frequently Asked Questions

Chlorine and other chlorine-containing products that contain hypochlorite are no longer allowed to be used for disinfection and thus the removal of scale. Moreover, is hypochlorite listed on the Danish Environmental Protection Agency's list of undesirable substances (LOUIS).

The reason why the Danish Environmental Protection Agency has listed hypochlorite on their list of undesirable substances is the lack of updated data for the potential carcinogenic and mutagenic effects of these substances. In addition, hypochlorite is suspected of reacting with naturally occurring substances and forming environmentally hazardous substances that accumulate in the aquatic environment.

You must use ProtoxHysan instead.

Hysan contains chlorine dioxide that does not form these dangerous substances. Hysan is used all over the world as a disinfectant, and also for a safe, disease-free drinking water supply.

ProtoxHysan can be used everywhere, both outside and inside.

Since the active substance (Chlorine dioxide) in ProtoxHysan only leaves a little salt and water on your surfaces, you can safely use the product for your entire mold removal. Several other anti-fungal agents often contain active substances that bind strongly to your surfaces and therefore remain in your indoor climate.


Protox Hysan contains a small amount of alcohol (<1%), it is the same alcohol you know from cleaning products such as glass and window cleaner. The alcohol has the same characteristic smell as glass and window cleaner, which disappears quickly when aired out after use.

ProtoxHysan is composed in such a way that when the liquid comes into contact with the acid molds, the chlorine dioxide is released (this is called "in situ generation").
In normal attacks, it is not necessary to add activator.

In case of massive infestations or in connection with disinfection (e.g. after rising sewage), activator must be used. This is a task for professionals who have completed the necessary courses.

When working with mold and other fungi, spores and "fungal dust" will be released. You should therefore always use a dust mask. Furthermore, you must always read the product's safety data sheet before use. This data sheet contains all information about the safety factors that must be observed, including whether respiratory protection is recommended.

Boring beetles are a collective term for several different species of insects that live in and on wood. Most common is the Alm. Boring beetle (Anobium punctatum), which is found in almost all older houses.

Attacks are most often seen as round or oval holes in the woodwork and sprinkles of "drilling flour" under the holes.

Read more here.

Carcinogen means cancer-causing.

ppm is a concentration indication. Directly translated, it means "parts per million" i.e. number of parts per million. The unit is often used at very low concentrations.

An indication of e.g. 10 ppm therefore means a concentration of 10 parts of the substance in 1,000,000, or converted to % = 0.00001% - then it is easier to write 10 ppm.

Chlorine dioxide is a very unstable and reactive gas which acts as a disinfectant because it breaks down (oxidises) the cell membrane of bacteria, fungi, viruses etc.

Chlorine dioxide is broken down very quickly by sunlight, leaving only oxygen and salt (table salt).

An activator is a product that starts or accelerates a reaction or process.

For example, the activator starts a massive release of chlorine dioxide i ProtoxHysan and ProtoxBiox.

An oxidizing agent is a substance that chemically breaks down mould, bacteria, viruses and bad odours.

Common to the oxidizing agents Protox use in ProtoxHysanProtoxBioxProtox AbsenceProtoxMille and Protox Cloudburst  is that they strain the indoor climate and the working environment as little as possible.