Is bathroom mold dangerous?

Air quality experts explain whether bathroom mold is harmful and the steps to take to reduce any concerns

blue tiled bathroom with double shower
(Image credit: Future PLC)

A small amount of mold in the bathroom is very common, and generally not a cause for serious alarm. Of course, we would want to get rid of it promptly to keep our bathrooms looking their best, but the moisture from steamy showers, bathtubs, running sinks, and flushing toilets does make the bathroom a prime spot for microbial growth. 

There are various ways you can get rid of black mold when it appears, and methods to remove black bathroom ceiling mold safely, which can often be a problem if there isn't enough ventilation, or if there has been a leak.

We turned to air quality experts to find out if black mold in the bathroom is dangerous and the steps to take if you are concerned about its presence.

Bathroom mold dangers

It's worth noting that mold in your shower or bathroom can increase the chance of it developing elsewhere, so check for mold in your house to tackle the issue before it spreads, and consider investing in one of the best dehumidifiers to reduce moisture levels around the house.

Marble shower with glass frameless doors

(Image credit: Future)

What is toxic black mold?

Toxic black mold – also known as Stachybotrys chartarum or simply 'black mold' – is a fungus that is greenish-black in color. It can produce toxic, microscopic chemicals called mycotoxins, which can have adverse effects on our health. 

These toxins are dangerous if ingested, and cause irritation and allergy-like symptoms if inhaled, particularly for those with allergies, asthma, or compromised immune systems. 

'Inhaling mold spores often leads to nasal congestion, throat irritation, coughing, and even eye discomfort sometimes,' says air quality and air purifier expert Milan Antonic at Air Purifier First. 'Even though they're not extremely dangerous for most people, if you're allergic to mold or have a compromised immune system, you could have a more severe reaction (lung infections, etc.).'

Common symptoms of mold exposure

Experts agree that prolonged exposure to high levels of mycotoxins can cause health issues. 'These tiny toxins are naturally toxic to our bodies, which is why the FDA regulates them in our food,' says Michael Rubino, an air quality and mold expert at HomeCleanse.

'Unfortunately, there are no regulations for levels within our indoor environments. To make matters even more complicated, some species of mold can release multiple types of mycotoxins.

'As an added contamination layer, bacteria grows in similar conditions as mold and can often be found growing right alongside it. Spores, mycotoxins, and fragments are small enough to be inhaled, absorbed, and ingested into the body. 

'Once inside, they trigger an immune response, which is the underlying factor in their ability to cause adverse health reactions. As the particles continue to enter the body, the immune system will attempt to keep up with removing them, but it can become overloaded or malfunction, particularly for those who are hypersensitive.'

toxic mold expert Michael Rubino founder HomeCleanse
Michael Rubino

Michael Rubino, indoor air quality and toxic mold expert, is the founder of HomeCleanse, a company aiming to end the worldwide health epidemic caused by poor air quality and toxic indoor environments. Michael is a council-certified Mold Remediator by IICRC and ACAC and a contributing member, sponsor, and speaker for the Indoor Air Quality Association.

  • Headaches and migraines
  • Joint and/or muscle pain
  • Digestive issues
  • Brain fog
  • Chronic fatigue
  • Flu and cold-like symptoms
  • Hair loss
  • Anxiety and/or depression
  • Mood swings
  • Skin issues such as rashes
  • Hormone imbalances

Michael Rubino points out that one of the trickiest things about issues like mold in the bathroom is that no two people will respond the same way to exposure. 'One individual may experience occasional brain fog, while another develops a dozen symptoms and an autoimmune disease,' he says.

How to identify toxic black mold

black ceiling mold

(Image credit: Alamy)

'Recognizing the type of mold is almost impossible for most people, and that's why I recommend everyone use mold test kits,' says Milan Antonic. Milan recommends the Mold Armor Do It Yourself Test Kit, available at Amazon which can be sent off to a lab. Alternatively, you can find them at a local hardware store.

As Logan Cox at John the Plumber St. Catherines highlights, not all molds are toxic, and the mere presence of mold does not guarantee the presence of mycotoxins.


Is mildew dangerous?

Michael Rubino says that contrary to popular belief, mildew is actually just a variety of mold. 'It’s not a separate entity. The term “mildew” basically refers to mold growth that’s light in color and powdery in texture. These mold colonies could be gray, white, or light green and grow in a flat format without much height, meaning they aren’t as fluffy and sponge-like as some other mold growth. 

'Quite a few species can fall under the “mildew” umbrella, such as Aspergillus, a “common mold,” according to the CDC. This particular species of mold can create toxic byproducts called mycotoxins, which is why mildew is no less of a home health threat than other varieties of mold.'

Keeping on top of cleaning, opening windows, removing shower curtain mold, and using the appropriate-sized exhaust fan will go a long way in keeping moisture levels down. And when if comes to updating your space, make sure you avoid common bathroom renovation mistakes that can make your bathroom moldy.

Millie Hurst
Section Editor

Millie Hurst is a freelance lifestyle writer with over six years of experience in digital journalism. Having previously worked as Solved Section Editor at Homes & Gardens and Senior SEO Editor at News UK in London and New York, Millie has written for an array of homes brands including Livingetc and Real Homes and was formerly Senior Content Editor at Ideal Home. She has written and edited countless features on home organization, decluttering and interior design and always hopes to inspire readers with new ways to enjoy their homes. She lives in Sheffield, South Yorkshire, and loves to weave nature-inspired decor and nods to time spent in Italy into her own home.