Mould encyclopedia

Acremonium

In nature, Acremonium is found in soil and dead plant material. The fungus can therefore also occur naturally indoors in smaller quantities. A larger occurrence is a sign of indoor growth on, for example, concrete, plaster, wet wallpaper or wooden materials.

Alternaria/Alternaria altern

The Alternaria genus, which is a parasite/rot fungus, typically grows in nature on plants, fruits and vegetables. It can also be found in rotten wood, compost and soil. But they also grow indoors. In terms of health, Alternaria can cause high fever and be an asthma and allergy trigger.

Alternaria altern sp is also an asthma and allergy trigger. This type of mould is known, among other things, as a cause of “baker’s lung” and “farmer’s lung”, as it occurs on grain and hay, among other things.

Visually, Alternaria can be recognized by black to olive-black or gray fungal colonies.

Aspergillus

Aspergillus spp is one of the most common moulds on damp building components and does not require much moisture to develop. The species can thus already begin growth at just 75 percent relative humidity on the surface of a material.

Aspergillus species can, due to their wide distribution, strong musty odor and large spore production, have major negative consequences for the indoor climate. Aspergillus is also considered a biologically active mould (SBAS) that can produce toxins.

This type of mould can thus cause infections in the lungs, respiratory tract, nose, sinuses and ear canals. In people with a weakened immune system or immune deficiencies, Aspergillus can lead to serious illness, where internal organs such as the brain and kidneys can also be attacked.

The fungus is transmitted by inhaling fungal spores in the air or from air conditioning systems. It is not contagious between people.

Visually, Aspergillus is characterized by forming colonies with white, yellow, orange-yellow and orange-green colours.

Aspergillus niger

Aspergillus niger is common in nature and in homes. The fungus forms black colonies that are often seen on, for example, vegetables and fruits, but can also occur on building materials and in potted plant soil.

Aspergillus niger thrives at high temperatures and at lower humidity levels than some other moulds. Therefore, it can grow even in areas with minor moisture damage. The fungus can be pathogenic for people with a weakened immune system.

Chaetomium

Chaetomium sp is a mould-like sac spore fungus that is cellulose-degrading and can cause surface rot. The fungus is often seen on plants, damp wood, plasterboard and wallpaper.

The Chaetomium fungus releases a large spread of mould fragments and can cause both allergic reactions and infections. It emits a characteristic and unpleasant mould odor.

The fungus is very easily recognizable, as it forms black, hairy colonies.

Chaetomium globosum

Chaetomium globosum is a fast-growing fungus that requires high humidity. It is frequently seen on concrete and materials that contain cellulose, e.g. wallpaper and wood. The colour can be from white to gray, can also be brown and black!

The fungus is usually only found in low levels in outdoor air. Therefore, even a small occurrence is a strong indication of current or past moisture damage. Chaetomium globosum can produce toxins that are suspected of causing problems for people living in moisture-damaged buildings.

Cladosporium

The majority of spores in the air outdoors come from Cladosporium moulds. The fungi, which are allergenic, live, among other things, on leaves from deciduous trees, dead plant parts and in soil. This type of mould can also be found in refrigerators and on wallpaper.

Cladosporium, which is a rotting fungus, is one of the most common mould groups. This is not least because they thrive very well outdoors, but also often occur in humid environments indoors.

This type of mould is not particularly toxic. Unfortunately, however, the spores from Cladosporium promote asthma or cause symptoms of asthma.

Cladosporium can be visually recognized by olive green and brown colonies.

Fusarium

In nature, Fusarium spp are found in the soil and various plants, e.g. grains. During World War II, many Russians experienced food shortages and therefore ate grains that had been under the snow over the winter. The grain was infected with Fusarium, which led to serious poisoning.

Indoors, Fusarium can occur in carpets and mattresses, damp walls, wallpaper, polyurethane foam, in humidifiers and areas with stagnant water. Some species can infect the eyes and nails, and can also cause keratitis. The fungus is also dangerous if inhaled and belongs to the group of particularly toxic fungi.

Mucor

Mucor is a water damage mould. This type of mould is commonly found on fruit and fruit-containing foods. It also grows on damp wood and is often seen in house dust.

Mucor can cause symptoms of hay fever and respiratory allergies.

Usually appears as white and grayish colonies.

Penicillium

Penicillium Sp is a fairly large and very extensive genus of mould. The type is among the most frequently occurring moulds in both indoor and outdoor air, as well as on damp building parts.

Penicillium can attack the majority of organic materials, especially damp building materials. It is especially known from soiled wallpapers.

The fungi form many, small spores that are extremely unhealthy for health. Penicillium should therefore be considered very seriously in indoor climate matters.

This type of mould most often forms white or slightly greenish colonies.

However, Penicillium is one of the mould species that we also enjoy greatly. For example, the bactericidal penicillin is secreted by, among others, Penicillium notatum and Penicillium crysogenum, while enzymes from Penicillium roqueforti are used in the production of blue cheeses, including Roquefort and Gorgonzola.

Stachybotrus

Stachybotrus Chartarum Sp, which is a water damage mould, breaks down cellulose-containing materials, such as wood. Often grows on wet or damp plasterboards covered with cardboard or wet wallpaper.

When this type of mould grows, it develops gaseous compounds that irritate the skin and reduce the immune system.

Visually, Stachybotrus Chartarum is characterized by forming dark colonies in brownish and greenish colours.

Streptomyces

Streptomyces spp is not a mould, but a group of bacteria that are primarily found in soil. Here they secrete substances that give the characteristic, earthy odor that is often associated with moisture problems.

Streptomyces spp often occurs when there is moisture in floor structures and screeds, but can also find their way into indoor dust when, for example, dogs or cats bring soil into the home.

Streptomyces spp can produce a wide range of organic compounds. Some of these can worsen the indoor climate and cause health problems.

Ulocladium

Ulocladium Chartarum occurs relatively rarely indoors, even in connection with moisture damage. However, at high moisture levels over a long period, the fungus can appear on, among other things, plasterboard, wallpaper and woodwork. Since the outdoor level is very low, even a low occurrence indicates a moisture problem.

Yeast

Yeast sp includes a large group of single-celled moulds. They are commonly found in both indoor and outdoor air.

Yeast is often found on damp surfaces in wet rooms and by windows. They are often greasy to the touch.

Visually, this type of mould appears in almost all colours. From white to red to black types. Unlike mould, yeast does not need oxygen to grow.

Other moulds (Mycelia sterilia)

Mycelia sterilia are fungi with sterile mycelium without known growth pattern, colour, or spore-forming cells, making them difficult to identify with certainty.