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The terms "mold" and "mildew" are often used interchangeably to describe those unsightly dark patches that can invade tile grout. These issues can arise in even the most spotless homes, whether due to an unnoticed bathroom leak, neglected cleaning areas, or a damp and musty basement environment.
Are mold and mildew truly the same, and what can you do to prevent their growth? Dive into the mold versus mildew discussion and learn expert tips on how to effectively clean and eliminate both.
Natalya Vilman/Getty ImagesHow to Identify Mildew and Mold
Molds, which are fungi similar to mushrooms, flourish in damp, oxygen-rich environments. While they play a beneficial role in decomposing organic matter outdoors, such as fallen trees, they become problematic indoors, where they can deteriorate wood, insulation, and other structural components if ignored.
Unchecked mold spores can travel through the air, spreading to other areas of the home. Exposure to mold can trigger allergy-like symptoms, including sneezing, a runny nose, skin rashes, and aggravated asthma.
Mold appears in various colors, textures, and forms, often presenting as fuzzy, slimy, or raised patches. Commonly green or black, it can also be pink and is typically accompanied by a strong, musty smell. Effectively cleaning and eradicating mold often requires professional intervention.
Mildew
Mildew is essentially a specific variety of mold. According to mold specialist Michael Rubino, "The term 'mildew' describes mold that appears light in color and has a powdery texture. These colonies can be gray, white, or light green and grow flat, lacking the fluffy, sponge-like appearance of other mold types."
Mildew is commonly found in moisture-prone areas like bathrooms and windowsills. Its flat growth pattern keeps it confined to surfaces, making it more visible and easier to clean. Additionally, mildew emits a milder odor compared to other molds.
Other Types of Mold
The CDC estimates there are around 1.5 million mold species, with Cladosporium, Penicillium, and Aspergillus being the most prevalent indoors. Certain molds, such as Stachybotrys chartarum (black mold), Penicillium, Byssochlamys, and Aspergillus, can produce dangerous mycotoxins.
It’s worth noting that terms like "black mold" and "toxic mold" are not scientific classifications but rather colloquial terms often used by the public and media.
Molds capable of producing harmful mycotoxins are frequently encountered in the food industry but are also prevalent in water-damaged structures. Interestingly, even certain mildew species can release mycotoxins. Unfortunately, these toxins are invisible to the naked eye, making it impossible to determine their presence simply by observing mold growth. [EPA]
What Are Mycotoxins?
The World Health Organization (WHO) explains that certain molds naturally produce toxic substances known as mycotoxins. These molds can develop on food and crops, particularly those grown in warm, humid environments, and are often found in cereals, coffee beans, dried fruits, and nuts.
Mycotoxins can also become airborne, potentially exposing individuals to these toxins. Depending on the type, duration of exposure, and toxin involved, people may experience symptoms such as skin irritation, vomiting, diarrhea, blurred vision, and respiratory problems. In severe cases, inhalation can lead to serious health complications or even death.
How to Prevent Mold
Since mold and mildew are fundamentally the same, the same prevention strategies apply. Rubino suggests the following methods to help stop mold from developing in the first place.
Reduce Moisture
Since moisture promotes mold growth, it’s essential to minimize it in your home. This involves cleaning up spills or standing water immediately, repairing leaks or structural problems that could let water in, allowing appliances like dishwashers and washing machines to air out, and ensuring wet items such as bathmats, shower liners, curtains, and towels dry thoroughly.
Keep indoor humidity levels between 35% and 50%. This might mean using a dehumidifier in damp areas like basements, running exhaust fans, or opening windows during activities like showering or cooking.
Clean Regularly
Regular cleaning not only enhances your home’s appearance but also helps prevent mold, mildew, and unwanted pests. Rubino advises using plant-based cleaning products, HEPA-filter vacuums, and maintaining a consistent dusting and deep-cleaning routine.
Improve Air Quality
Enhancing your home’s air quality can significantly reduce mold, mildew, bacteria, pet dander, and other unwanted contaminants. Maintain your HVAC system regularly and opt for high-grade MERV filters to minimize airborne pollutants. Air purifiers are also highly effective in preventing mold and mildew while reducing dust, allergens, bacteria, and viruses.
How to Remove Mold
Stay calm—there are safe methods to eliminate mold and mildew from your home. Once removed, follow the prevention tips mentioned earlier to stop it from returning. Here’s what you need to know to tackle mold or mildew effectively.
When cleaning mold or mildew, consider using personal protective equipment (PPE) to safeguard your skin and respiratory system. Wear gloves, goggles, and a mask, and ensure the area is well-ventilated during the process.
Eliminate the Source
To effectively clean mold and prevent its recurrence, it’s crucial to eradicate it entirely at its source. Rubino emphasizes, "Every trace of contamination must be removed, including the colony, roots, dead mold particles, mycotoxins, and any bacteria present."
If any of these elements remain, the mold colony may persist, and the indoor environment could still be filled with harmful microscopic particles. In such cases, hiring a mold remediation expert to assess the growth, test for mycotoxins, and thoroughly clean the area may be necessary.
Tailor the Treatment
The approach to cleaning mold should vary based on the type of surface it’s on. Mold behaves differently on nonporous, porous, and semi-porous surfaces, requiring specific cleaning methods for each.
- Nonporous surfaces: For mold on nonporous surfaces like bathroom tiles or sealed countertops, use a botanical cleaner (Rubino suggests Benefect Decon 30). Let it sit for 30 seconds, then wipe with a microfiber cloth, which removes 100 times more particles than regular rags. Repeat the process at least three times to ensure all contaminants are gone.
- Semi-porous surfaces: Cleaning mold on semi-porous surfaces, such as grout or hardwood floors, can be more challenging. Rubino explains, "Mold roots can penetrate the surface, making complete removal difficult. To ensure the surface is contaminant-free, all particles must be eliminated." Follow the same cleaning process as for nonporous surfaces, then seal the area. For grout or caulk, hydrogen peroxide can help remove mold—monitor for quick regrowth, which may signal a deeper issue requiring professional intervention.
- Porous surfaces: Mold on porous surfaces is often too difficult to clean thoroughly. Rubino advises replacing the affected item to avoid ongoing mold exposure.
While bleach is often promoted as an antiseptic and anti-mold cleaner, the U.S. Environmental Protection Agency (EPA) states it is ineffective at removing mold or mildew, which is essential for preventing future growth. Although bleach can be used in some cases, addressing the underlying moisture problem is critical to fully eliminate mold and stop it from recurring.
When to Call a Professional to Clean Mildew or Mold
While small mold or mildew areas can often be cleaned independently, certain situations warrant professional help. Consider the mold’s location, the size of the affected area, and whether household members are experiencing health symptoms. If mold returns after cleaning, it’s a sign that professional remediation may be necessary.
The EPA recommends hiring a professional for mold growth exceeding 10 square feet. If mold has infiltrated your HVAC system, it can spread through the air, causing further problems—another scenario where professional assistance is essential.
Similarly, if the water damage is widespread (regardless of the area), located within walls, caused by sewage issues, or involves toxic mold (such as black mold) or rapid spreading, professional assistance is crucial. Additionally, seek professional help if you or anyone in your household experiences health issues like skin rashes, coughing, congestion, or other respiratory problems.
