Allergy Symptoms? Tips to Eliminate Mould Growth

Summer represents the peak of mould season in many parts of the world, and with the ongoing COVID-19 pandemic and looming possibility of new outbreaks, resurgences and quarantines, many people are also feeling a nagging worry about what could be hiding inside their home. 

Rather terrifying tales of mould invasion abound on the internet and across social media – stories that spark many questions. 

'How dangerous is mould?' 'How quickly does it grow?' 'Are some types of mould more dangerous than others?' 'What can you do if your house has mould?' And perhaps most commonly, 'Is 'toxic' black mould really that toxic?' 'Can it actually make my family sick?'

Luckily, there are things you can do for peace of mind. But first, let’s start off with some comforting news. Well, 'comforting' might be a little subjective, but here goes.

We are all constantly breathing in a 'thick soup' of fungi, bacteria, and other microbes, plus their byproducts, according to Professor Naresh Magan, a mycologist at Cranfield University in England. You may be thinking that’s not very comforting at all. But it’s actually great news! It means that our immune systems have adapted over 500 million years to cope with the fungus among us.

For some though, trouble at home starts during mould season, when warm, damp weather triggers mould to release its spores. And while some of us are lucky enough to only have extra fungus trouble during a single season, others have it much worse.

If the ambient humidity in your area is above 80%, congratulations, it’s always mould season.

Any kind of mould spore can colonize your living space, but there are some types of mould that can pose serious health risks (especially to those with allergies, asthma, weakened immune systems, or lung disease) if they are present in your home. These include: Penicillium, Cladosporium, Chaetomium, Alternaria, Aspergillus, and Stachybotrys, which is also known as 'black mould.'


According to the Asthma and Allergy Foundation of America (AAFA), if you have an allergy that occurs over several seasons, you may be allergic to the spores of moulds or other fungi. As mentioned above, mould, mildew, and fungi are all around us.

They’re different from plants or animals in how they reproduce and grow. The 'seeds,' called spores, travel through the air. Inhaling the spores causes allergic reactions in some people. Allergic symptoms from fungus spores are most common from July to early fall. But fungi grow in many places, both indoors and outside, so allergic reactions can occur year-round.

The symptoms of mould allergy are often very similar to the symptoms of other allergies, such as sneezing, itching, runny nose, and congestion.

Mould spores get into your nose and can cause hay fever symptoms. They also can reach the lungs and trigger asthma.

Sometimes, the reaction happens right away, and sometimes a mould allergy can cause delayed symptoms, leading to nasal congestion or worsening asthma over time. If symptoms worsen when you enter a damp or mouldy room like an unfinished basement, it may mean you have a mould allergy.

Rarely, some people can have a more severe illness called allergic bronchopulmonary aspergillosis. In this condition, there is both an allergic and an inflammatory response to the mould. Symptoms may include severe wheezing, coughing and shortness of breath, much like asthma.


Mould spores stick to surfaces and, if conditions are sufficiently warm, damp, and undisturbed, will extrude tendrils which turn almost any surface into food.

Wood, ceiling tiles, shower curtains, rubber, carpet, soil, dust; just add water and it’s all food to the mould.

How do you know when mould has arrived in your home? That’s easy: you’ll smell it. Mould doesn’t always have a strong smell when it’s present, it’s often described as musty. Others have described mould smelling earthy, or resembling the odour of wet socks or rotten wood.

For many homeowners, the smell is unpleasant and pungent. As mould grows, it can emit gases known as microbial volatile organic compounds (MVOCs).

Technically, it’s not just mould you are smelling, but the chemical compounds that are released at different stages of the mould’s growth.

What effect does all this fungal activity have on health? Generally speaking, we know that there are two main ways mould can engage the immune system, and they depend on whether your system is underpowered or overactive.

If you have a weakened immune system, for example, if you’re going through chemotherapy or have had a recent organ transplant, fungus can easily colonize the lungs and begin treating your body as it would concrete or wood panelling, says Professor Matthew Fisher, an epidemiologist at Imperial College London.

It’s much more likely that you have an overactive immune system that sounds the alarm by triggering an allergic response when confronted with mould spores and filaments.

Pesky filaments land on the mucous membranes of our eyes, nose, and mouth, causing eye-watering, itching, sneezing, coughing, or even asthma attacks. For most people, these symptoms will stop as soon as you leave the mouldy room.

But experts estimate that 5-10% of the population are more sensitive than others. If your home becomes colonized by a toxic fungus, you’ll be inhaling those spores every day and you may potentially become sensitized to them.

Sensitization means your body recognizes a substance and mounts an extremely aggressive response to even the faintest traces of it. If you already have asthma, you might get a particularly severe 'fungal asthma.'

Even more alarming, a decade of studies show a strong link between mould exposure in infants and the development of asthma symptoms by age three. Maternal smoking is the only thing more correlated with infant onset asthma than mould exposure.


The best way to minimize mould allergies inside your home is to prevent mould from forming in the first place.

Here are some things you can do to limit mould growth inside your home:

  • Lower the humidity. Hot, humid houses are breeding grounds for mould and mildew. Maintain the temperature between 68F and 72F and keep relative humidity below 60%, ideally between 35-50%. Dehumidifiers remove excess moisture from the air and air conditioners keep the overall temperatures comfortable without opening windows and letting in humid air. An air conditioning unit with a high-efficiency particulate air (HEPA) filter will help to trap mould spores before they can come inside. Be sure to change filters regularly and make sure drain pans and drip lines are clean.
  • Ventilate the bathroom and kitchen. Be sure your home has adequate ventilation, including exhaust fans in bathrooms and kitchens.
  • Keep things neat and clean. Mould grows on dirty surfaces, so clean up spills immediately and dust your home regularly. Watch for mould growth in trash cans and recycling containers and spray them regularly with Vital Oxide. Clean out the refrigerator weekly and throw out food before it can become mouldy. Wash shower curtains and bathroom tiles regularly with Vital Oxide to inhibit mould growth.
  • Say no to carpet. Remove carpeting in bathrooms and basements and use hardwood, tile, or linoleum flooring and washable area rugs. Both of these rooms are typically moist, and adding the element of carpet often results in a recipe for optimal mould growth. If you must use carpet in your home, choose low-pile instead of high-pile carpeting and vacuum regularly with a vacuum cleaner that has a HEPA filter. After vacuuming, spray the carpet with Vital Oxide to prevent mould growth and to eliminate allergens.
  • Don’t overwater plants. If you have house plants, don't overwater; it encourages mould in the soil. If you suffer from a mould allergy, keep house plants out of the bedroom.
  • Keep the fridge clean. Wipe up excessive moisture daily to avoid mould growth. Discard mouldy or out-of-date food. Regularly empty and clean the refrigerator dripping pan with Vital Oxide and clean or replace mouldy rubber seals around doors.
  • Take care of things before they get worse. Mould grows within 48 hours of water damage, so fix any leaky pipes and clean up water immediately.
  • Clean mould-covered surfaces with Vital Oxide. To remove mould from hard surfaces, clean thoroughly with a scrub brush and rinse with water. Then, spray our mould-busting formula, Vital Oxide, from a distance of 12 inches until visibly wet, and allow it to air dry. Vital Oxide can be sprayed directly on both hard and soft surfaces to eliminate mould and mildew. Be sure to dry the area thoroughly. You can use a fan to speed up drying time. Remember, moisture is mould’s best friend.


Mould allergies can make you feel uncomfortable in your own home. To decrease mould and inhibit new growth, you need to use the right product.

Bleach and other conventional cleaners only remove stains and kill surface mould, not the membrane that lives under the black, fuzzy growth. The mould membrane is where the heart of the problem truly lies. If you try using bleach to kill mould, it will usually return with a vengeance.

The chemical structure of chlorine bleach makes it unable to penetrate porous surfaces like drywall, wood, concrete, upholstery, or carpeting, which means that mould membranes will simply retreat deeper into whatever surface they're on to avoid the chemical. The surface may appear clean, but internal roots will continue to grow.

Once exposed to bleach, the mould will recognize the bleach as a threat and can actually use it as a fungal food to grow more rapidly.

That's right, using bleach to kill mould can actually feed the problem!

study conducted by researchers at the University of Oregon proved this, and found that fungi was able to survive and re-colonize following cleaning treatments with bleach.

In addition, the Environmental Protection Agency (EPA) has specifically advised against the use of bleach for mould remediation. There is a better way.

Vital Oxide is a multi-purpose, ready-to-use disinfectant cleaner and mould killer. It eliminates mould and mildew on a molecular level, neutralizing spores and inhibiting fungal growth without damaging the surfaces treated.

Unlike bleach and other products that are only effective on non-porous surfaces, Vital Oxide can penetrate both soft and hard porous surfaces like carpets, upholstery, drywall, concrete, and wood and destroy the roots of tough mould and mildew.

Using Vital Oxide to clean and disinfect your home regularly will help to prevent mould growth before it has a chance to take hold.

Learn more about the science behind the product, as well as tons of great tips on cleaning, disinfecting, and more. If you have any questions, please get in touch – we’re here to help.