Is Mold In Bathroom Dangerous

Stand: 12.04.2019 09:52 Uhr | Archive Conventional cleaners don’t stand a chance against nasty fungal plaque on grout lines. Mold spores are everywhere in the air. They find ideal living conditions in the warm, humid climate of bathrooms. Mold-infested tile grout often looks rotten, but there is usually no health risk. Only allergy sufferers and people with weakened immune systems should stay away as a precaution and leave the cleaning to others. But: Which remedies help best against the black coating? Markt compares home remedies and special cleaners (prices per 100 milliliters):

  • Methylated spirits for 0.20 euros
  • Cleaning alcohol (isopropyl alcohol) for 2.95 euros
  • Hydrogen peroxide for 2,31 Euro
  • Mildew remover with sodium hypochlorite for 0,38 Euro
  • Mold remover with benzalkonium chloride for 2,00 Euro

Basically, all products should be used only with protective gloves.

Methylated spirits: mold dead, stains remain

Methylated spirits are an inexpensive but inedible variant of potable alcohol (ethanol). It is suitable for all surfaces. To reliably kill mold, methylated spirits should be worked in with a rag or brush. However, the stains often do not disappear or fade only slightly. The reason: alcohol has no bleaching effect.

Cleaning alcohol: Good for the environment and health

Isopropyl alcohol is available at pharmacies. It gives off the typical hospital smell. It is often used there as the main ingredient in disinfectants. Similar to methylated spirits, cleaning alcohol should be worked thoroughly into the joints, for example with a cloth or brush. The German Federal Environmental Agency even recommends alcohol for mold removal, as it is considered harmless to health and the environment. It simply evaporates.

Hydrogen peroxide: Three-percent solution helps

Many people know the household remedy hydrogen peroxide from the hairdresser: in higher concentrations it makes hair blond. A three-percent solution is enough to kill fungal spores on plaster and joints. To make the liquid solution stick to the wall better, it is best to place a suitable strip of kitchen paper on the joint and apply the hydrogen peroxide to it with a brush. After half an hour, brush it off well.

Mold cleaner with chlorine: Smell like a swimming pool

“Clean without scrubbing”: this promise is kept by the chlorine cleaner in the practical test. Mold removers with sodium hypochlorite contain chlorine. They therefore usually emit an intense odor like that of a swimming pool. Chlorine can irritate the respiratory tract and must not be used together with other cleaning agents. In combination with acid cleaners, highly toxic chlorine gas can be produced. In the practical test, however, the cleaning agent with chlorine was the most convincing: after 15 minutes of exposure time, there was almost nothing left of the mold.

Mold cleaner without chlorine: A lot of scrubbing necessary

An alternative to chlorine-based mold removers are products containing the active ingredient benzalkonium chloride. According to experts, it is less problematic for health and the environment. Disadvantage: Testers must scrub vigorously to remove mold as thoroughly as with a chlorine-containing mold remover.

Ventilate well and rinse with water

With or without chlorine: Mold cleaners they are not suitable for all surfaces. This is because they leave behind residues that can pollute the air in the room. After exposure, rinse thoroughly with clean water. This can be done quickly in the shower. On plaster, however, the residues are often stubborn. Important: Ventilate well when spraying the cleaner.

Silicone joint hardship

In practical tests, all cleaners have failed on a moldy silicone joint. The reason: The mold eats into the soft material, so that the cleaners have no chance. From a health point of view, a discolored silicone joint is harmless. Anyone who is bothered by the black spots should have the silicone joint renewed by a specialist company. To prevent the fungus from returning so quickly, sanitary silicone is a good choice. It contains fungicidal substances. Further information This topic in the program:

Market | 04/15/2019 | 8:15 p.m.

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15 min 6 min

  • First warning signs of mold infestation
  • Causes of mold
  • Dangers of mold

First warning signs of a mold infestation

Long before mold shows itself with visual clues, a harmful infestation of mold may be present. Typical indications are usually musty odors that cannot be associated with the materials present and reappear promptly after airing. On the inner surfaces of exterior walls as well as in the area of thermal bridges, damp spots and color changes can often appear at an early stage, which do not disappear even after checking and adjusting normal room usage behavior. Check not only the room walls, but also hard-to-reach areas such as the back of furniture for slight changes and undefinable dust. Mold spores are easily mistaken for dust due to their small size and show up in shades of gray, green and white, depending on the type of mold. In addition, the health of the occupants should be kept in mind. The first signs of health problems caused by mold exposure manifest themselves similarly to a flu-like infection with constant fatigue, headaches, aching limbs and problems with the bronchial tubes. If you are unaware of an illness of this type and the symptoms last for more than 14 days, medical clarification should be sought. However, many other symptoms of unknown origin may also be caused by mold infestation. A test can measure the mold infestation and provide you with certainty.

Causes of mold

In fact, it is inevitable that mold spores will enter the living space because they are microscopic components in the air. Mold on food or items that have been moved from outdoors to indoors can also carry the airborne spores into the home. If the premises then offer good growing conditions, the fine spores adhere and begin to develop. This can happen in old buildings as well as in the most modern new buildings, where the natural drying of the building materials has not yet been completed. The occurrence of mold has many causes. However, for mold to thrive, it requires three basic criteria:


If the relative humidity in the air is higher than 60%, or the relationship between temperature and humidity is unbalanced, moisture will condense on the surfaces in the room. The higher the temperature, the higher the moisture absorption capacity of the air (relative humidity). The greater the difference in temperature between the air in the room and the surface of the building component (dew point), the more condensation can form.


In addition to humidity, temperature is a major factor in mold growth. The higher the difference between the surface temperature and the air temperature, the more readily moisture from the air settles on surfaces as condensation. At temperatures around 15° Celsius, this effect can already occur at a relative humidity of 60%.

Nutrient supply

Molds prefer a pH-neutral environment with a pH value of 5 to 8. In addition, the mold needs air circulation in order to be supplied with organic material that is not found in the substrate. From these particles, the mold gains its energy. The coincidence of factors favors the growth of mold indoors. A good heating and ventilation system reduces the risk of mold spores settling in the home. However, it is a widespread misconception that ventilation and heating alone can eliminate the causes of mold.

Cause: Usage habits or building defects

The usage habits of the room users are widely considered to be the main aspect for mold growth. Wrong heating and airing is with exact cause research however usually only an intensifier of the problem. Only 10% of mold damage can be attributed to incorrect usage behavior alone and is related to insufficient fresh air supply, which in combination with irregular heating (e.g. indirect heating of several rooms through open doors, not heating and ventilating unused rooms). Find out more about “Proper ventilation and heating” here. Building defects are much more often the cause of mold. For example, moisture can penetrate through defective or missing building seals in the area of the roof or basement. Leaky pipes and joints, as well as damage to water and heating pipes or cracks in building materials also allow moisture to penetrate and can become the cause of mold.

Cause: unsuitable remediation measures

Sometimes renovation measures can also become the cause of mold. Newly installed windows can even promote mold growth in some cases if this is the only energy-saving measure and in the future the wall surface will be the coldest point in the room, where condensation forms as a result. Thermal bridges, caused for example by insufficient insulation, can promote the escape of heat from the inside to the outside. Condensation can form on cold wall surfaces where heat escapes when moist air hits them. This circumstance is one of the frequent causes of mold. Typical areas for thermal bridges are found on window and door constructions, on two- or three-dimensional exterior wall corners, on roller shutter boxes, radiator niches, and on uninsulated reinforced concrete components. Without appropriate consideration of the problem in heating and ventilation behavior, living conditions can thus arise for mold that are conducive to growth.

What makes mold dangerous?

Mold infestation is immediately harmful: mold spores are tiny and already endanger health when the actual mold infestation has left little or no visible trace. The World Health Organization (WHO) reports that in damp and moldy dwellings, the burden on the respiratory tract of the occupants is very high and there is an increased risk of allergies, asthma and other respiratory diseases. In addition, there is the varying potential danger posed by various types of mold: some fungi can colonize the lungs when the spores penetrate them. The human body provides the right balance of moisture and heat necessary for growth. Although this danger exists primarily in people whose immune systems are severely compromised, this is when mold becomes exceedingly threatening. How does mold threaten health? While some molds primarily negatively affect the building fabric and air quality in general, others are downright dangerous. This is especially true for mold species that develop mycotoxins. Mycotoxins are mold toxins that can lead to acute poisoning. They can accumulate in the body if the body is exposed to high concentrations over a long period of time. If the immune system is already weakened, mycotoxins can place an additional burden on the organism and promote the invasion of other pathogens. Accordingly, people with chronic diseases such as allergies, autoimmune diseases, patients with cancer and HIV diagnoses, children and adolescents, and the elderly are considered to be particularly at risk. Mold spores are always found in the air. Only when they encounter a suitable nutrient medium do the spores develop into a new fungus, which, however, initially grows just as invisibly as the spores. The concentration of mold spores in the air shapes the environment: the fungi can settle on food and be absorbed by the body through this as well as through the air we breathe. Uniform limit values are lacking The danger of mold contamination by spores and their metabolic products is known in many places. However, there are no uniform findings on limit values above which the concentration of mold spores can lead to a health hazard. The application of a precautionary principle is therefore advisable and should be carried out in the sense of the housing hygiene and the health of the inhabitants already, before it comes to an illness or a harmful influence. Accordingly, expert support is already advisable at the first mold settlements; from half a square meter of infested surfaces, a specialist should definitely be consulted.

Do you have any questions?

You have questions about Baumit products or the topic “remediation systems”. You are looking for a craftsman or building material dealer to buy the products. Please contact us. Information on cookie settings Please agree to the storage of the cookies listed below or personalize them! Required cookies Analytics and statistics Marketing and re-targeting. * I hereby consent to the cookies listed above. Cookie settings These cookies are required for the operation of the website and cannot be turned off. Such cookie is set only in response to actions you perform, such as language, currency, login session or privacy settings. You can set your browser to block these cookies, but our website may not work if you do so. More details keyboard_arrow_down Less keyboard_arrow_up These cookies allow us to determine visitor frequency and track traffic sources by collecting information in records. These help us understand which products and activities are more popular than others. More details keyboard_arrow_down Less keyboard_arrow_up Marketing and re-targeting These cookies are usually set by our marketing and advertising partners. They are used by them to create an interest profile of you in order to subsequently show you advertising that is relevant to you. If you do not consent to the use of these cookies, you will not benefit from personalized advertising. More details keyboard_arrow_down Less keyboard_arrow_up ** Coupon can only be redeemed once for an order in the webshop Calmwaters. Not combinable with other promotions or vouchers. No cash payment possible. The cozy warm bathroom is a space to feel good and relax. But unfortunately it is at the same time a place where mold likes to spread. And once it is in the apartment, it is often difficult to get rid of the mold. In this guide, we show you how to remove the unwelcome visitor and explain how the infestation develops, how you can recognize it, what types there are and how you can prevent it.

How does mold actually develop?

In nature: a useful helper

In natural environments, mold is responsible for decomposing dead organisms. This allows, for example, the renewed conversion of plant remains into water and carbon dioxide. The molds spread as spores in the air and form microscopic roots on the object in question, provided it can serve as food for them. If there is enough moisture due to condensation or humidity, decomposition begins afterwards.

In the apartment and bathroom: dangerous co-inhabitant

Mold can be dangerous within your own four walls: a spoiled apple is not worth mentioning. A room infested with mold, on the other hand, can have serious health consequences in the long run. This is because the coating is capable of triggering allergic reactions or exacerbating existing illnesses and even causing permanent lung damage. In addition, the building fabric can be damaged in the long term. This is a particular problem in rented apartments, as it is often difficult to prove who exactly is responsible for the infestation. Often, it is simply the conditions that prevail in most bathrooms: High relative humidity and organic materials such as wallpaper or fabrics as a substrate provide ideal conditions for the fungus to take root. An additionally acidic substrate provides even better conditions. Tip 1: If you suspect that mold – already discovered or still undiscovered – is responsible for health complaints, it is best to call in your family doctor or an advisory center for environmental medicine as a precaution. Tip 2: To prevent disputes, it is advisable to report the infestation directly to the landlord. In this way, the landlord can directly examine the building fabric for causes. In case of conflict, you should seek legal as well as professional advice.

Detect mold

Determine the infestation

It is important that you notice as soon as possible whether fungal infestation is spreading in your bathroom. Because the sooner you recognize the development, the sooner and easier you can take action against it. Specially trained sniffer dogs or tests submitted to laboratories can reliably detect mold before it is even visible. However, there are also ways to carry out investigations yourself. The following tips will show you how to recognize an impending infestation.

Noticing mold infestation

Typical locations

Mold classically appears in areas such as room corners, near the shower pan, on the bathtub, on the shower curtain, on silicone joints, around the sink or underneath the sink. If you have murals or similar items on the outside wall, you should inspect these areas as well. Likewise, the area behind a washing machine can be hazardous.


Musty, foul-smelling room air, which remains in the room even after airing, indicates that there is an infestation. This is because the metabolism of mold produces organic compounds with a corresponding odor. Mold spores, which are present in the air in case of heavier infestation, intensify the odor.


In most cases, if you look closely, you can see the fungi with the naked eye. Especially on a light background, the colored or dark spots stand out.


Your own sense of health can be a reliable alarm signal. Unexplained headaches or abdominal pain, general malaise or even fungal skin diseases are a possible indication.

Types of mold

According to estimates, there are about 250,000 species of mold worldwide, of which only 100,000 are known. Few of these varieties occur in living spaces, so you can definitely remember the most common ones and thus recognize them more easily. Basically, you can distinguish them by their colors, for which the fruiting body of the mold is responsible. For a professional determination you should nevertheless rather consult an expert. In the table you can see the different types of the most common fungi, their characteristics and appearance as well as the possible health effects.

Species Special features Health effects
Green mold, “Aspergillus fumigatus”. Is the most common variety. The spore carriers are green, while the remaining components are gray to whitish. It often occurs in damp areas such as the bathroom and can form different consistencies, but usually a fluffy coating. It often co-occurs with other species, creating a colorful mixture. The fungus contains the toxin gliotoxin. This is not excessively harmful to humans or animals, but has an immunocompromising effect and can cause allergies, asthma and headaches, as well as permanently damaging the lungs.
Black mold, including “Aspergillus niger” or “Stachybotrys chartarum”. It can form from numerous different mold species and genera and is the most feared variety. It occurs in the bath and can exist in both cold and warm temperatures. Depending on the species, the dry and powdery or slimy gray. For humans due to the high robustness enormously dangerous. It can cause different diseases such as allergies, kidney diseases as well as infectious diseases.
White mold Turns dark only after a while and therefore usually remains unnoticed at first. Is often found in the bathroom in corners, niches or furniture on exterior walls. Irritates mucous membranes and can lead to colds, skin diseases, aching limbs, scratchy throat or chronic bronchitis.
Red mold, “Neurospora” or “Chrysonilia sitophila”. Requires large amounts of cellulose to grow and therefore often develops on paper wallpaper. The coating has a dry to slimy consistency. Red tones and color intensities may vary. Can cause lung diseases such as asthma.
Yellow mold, “Aspergillus flavus”. Appears more ochre or brown than true yellow and is therefore less noticeable. It is less common in Germany due to higher hygiene standards. Consistency ranges from dry, flaky to granular to greasy. Produces the toxin aflatoxin and, like black mold, is particularly hazardous to health. It can cause liver cancer or heart failure.

How to get rid of mold

Remove mold properly

You can remove small areas of up to half a square meter, which only have surface infestation, on your own. To do this, it is better to wear gloves, face mask, goggles and, depending on the infestation, disposable coveralls to protect your health. It is also important to clean the infested area completely. Because even dead parts can be harmful to your health. Attention: If you have allergies, chronic illness or a weakened immune system, do not do the cleaning yourself and do not be present in the room during the cleaning.

Eliminate mold infestation

The following tips will show you how to permanently eliminate the infestation:

  • You should completely remove wallpaper or infested silicone joints and then clean the underlying wall with 70 – 80 percent methylated spirits (ethyl alcohol) or rubbing alcohol and allow it to dry sufficiently. You can bind spores and bacteria by moistening or pasting the wallpaper in advance. Then you can renew the damaged areas.
  • Rub plaster surfaces or other porous materials with methylated spirits or three-percent hydrogen peroxide solution. The advantage of hydrogen peroxide is that it has a bleaching effect and therefore removes stains at the same time. However, you should be careful with sensitive surfaces such as wood or furniture and test the agents on an inconspicuous area beforehand.
  • Special mold cleaners, whether with or without chlorine, you must rinse thoroughly with clean water after use and additionally ventilate well. These can themselves be hazardous to health. In addition, the cleaners are not suitable for all surfaces, so you should always pay attention to the manufacturer’s instructions.
  • A final disinfection of the place is usually not necessary. In addition, the bacteria can form an immunity against the active ingredient. Furthermore, you should not use vinegar for cleaning, as it even serves as food for some types of mold.
  • Waste that has come into contact with mold should be disposed of in a plastic bag with the household waste.

Prevention is the key

To prevent mold from growing in the first place, you should follow a few tips for prevention. For one thing, it does no good to remove mold without addressing the causes of the infestation. And for another, it’s always better if the infestation doesn’t occur in the first place.

Tips for mold prevention

  • Ventilate properly Keep humidity levels as low as possible. To do this, you should ventilate well after every shower. And even if you don’t shower, airing three to four times a day for 5 – 10 minutes is a good guideline. Depending on the load on the room air or weather conditions, even 10 – 20 minutes of ventilation may be necessary and at the very latest when condensation forms on windows and mirrors. For bathrooms without windows, a home ventilation system is recommended.
  • Heating While airing, you should turn off the heating to save energy. Then turn the heating back on, preferably at a temperature between 18 and 22 degrees Celsius. The warm air can better absorb the moisture. In addition, the heating circulates the air, which makes mold less likely to grow.
  • Remove damp laundry Damp towels or laundry is better dried outside! This way you lower the risk of increased humidity.
  • Keep surfaces dry After showering, it is advisable to remove standing water with a rag or squeegee. This will prevent water from collecting in the joints.
  • Furnishings Furnishings can help reduce the risk of mold. Strongly cooling exterior walls and corners should allow air to flow past. In addition, do not block radiators. In addition, avoid placing too many plants in the bathroom, as they increase humidity.
  • Check drains If you notice areas on the shower or other drains that are permanently damp, the inlets and outlets could be defective. You need to have these repaired immediately. So keeping your eyes open pays off!

No mercy to the mold

With this, you have the knowledge you need to prevent mold in your bathroom in the first place. And if an infestation does occur, you can recognize it quickly and eliminate it immediately. This will keep you happy in the bathroom for a long time and you can make your bathroom a pleasant place of well-being. Everything you need for this, you will find in our store. Large selection and convenient delivery to your doorstep included! And if you have any further questions, we can be reached at [email protected]. Is Mold In Bathroom Dangerous.

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