Preventing and Managing Mold, Bacteria, and Viruses
Cleaning is a top-level strategy for removing mold and bacteria. This work can be quite a chore but it is necessary to keep yourself and your family healthy. A few additional steps can be taken to reduce the possibility of these microbes causing a problem around your home.
Utilize natural light and circulating air
- Open a window or turn on a fan to move moist air out and reduce the likelihood of mildew forming in the bathroom. Mold and mildew are often a problem in bathrooms because of the moisture.
- Use the sun: UV rays can kill bacteria, and leaving items exposed to strong sunlight for several hours can help to disinfect them.
Stop mold from growing by fixing leaks right away
- Fix leaky pipes or water spills right away to help make sure that mold never has a chance to start growing.
- Get help–if your mold problem is extensive, you may want to consider hiring someone to help. For more information about mold, see the US EPA’s Guide to Mold, Moisture, and Your Home.
Practice clean kitchen techniques
- Ensure that raw foods such as meat are kept separate from other foods in the refrigerator to avoid intestinal problems caused by foodborne illnesses.
- Clean counters and cutting boards thoroughly after they have come into contact with raw foods. If a cutting board is not dishwasher safe, clean it thoroughly with warm soapy water after use.
- Make sure that cold foods stay cold and hot foods stay hot to keep bacteria from growing. Keep your refrigerator at 40°F or below and put leftover food in the refrigerator as soon as possible.
- Cook meats to the right temperature to make sure they are safe to eat: 145°F for whole meats, 160°F for ground meats, and 165°F for poultry.
- Wash hands frequently to help prevent transmission of pathogenic bacteria or viruses. Soap and water are a powerful tool and in most cases are just as effective as antibacterial soaps.
Be careful with children, toys, and pets
- Keep toys clean. Children’s bath toys can retain water, which encourages the growth of mold.
- Avoid sharing bath towels. Sharing is not recommended since this can spread bacteria and viruses, especially when someone in the household has a cold.
- Wash hands after playing with pets or handling pet waste.
Low Impact Approaches
Natural Cleaners for Mold, Bacteria, and Viruses
Various combinations of household items such as vinegar, baking soda, and plain soap can be used as cleaning agents in the home and are just as effective as harsher chemical products for many applications. Whether you want to avoid using these harsh chemicals because of asthma or other sensitivities or are just looking for a cost-effective set of cleaning tools, the following list highlights the most important cleaners.
- Vinegar works best at full strength (5% acetic acid) but the addition of several drops of essential oil will improve the smell for those that are sensitive. Vinegar is effective for cleaning mildew in the shower or can be used as an after-shower spray to prevent the growth of new mildew. Vinegar can also be used to kill some bacteria and viruses, including Salmonella and E. coli, and is useful for cleaning counters or cutting boards and removing smells.
- NEVER mix vinegar with bleach or ammonia because it forms harmful chlorine or chloramine gases. Be careful not to clean with vinegar and then with bleach after, as the residue may still react.
- Baking soda has antifungal properties and is registered by the US EPA as a biopesticide.
- Mix baking soda with water to make a paste that is effective at removing mold or mildew in the grout between tiles. Baking soda has many properties that make it useful as an all-purpose cleaner and can be used as a scouring agent.
Tea tree oil
- Tea tree oil is more expensive than some other natural remedies but is effective at killing mold and mildew. After scrubbing off mildew using a tea tree oil solution, apply a little extra to prevent more mildew from growing back.
- Many bacterial species are susceptible to tea tree oil, including Streptococcus pyogenes, Staphylococcus aureus, and Escherichia coli.
- Salt is a microbial inhibitor. Many microorganisms need moist conditions to thrive, making salt an efficient way to reduce the amount of water available for microbes to grow.
- Salt also interferes with microbe enzyme activity and weakens the molecular structure of bacterial and fungal DNA.
Household hydrogen peroxide
- A 3% hydrogen peroxide solution can be used to remove and prevent the growth of mildew and mold.
- Hydrogen peroxide is registered as a sterilizer and is effective against the HIV-1 virus, Hepatitis B, Hepatitis C, Mycobacterium tuberculosis, and Norovirus. Higher concentrations of peroxide are available as cleaning products and are also effective against many pathogenic bacteria and viruses, but are corrosive to skin and eyes.
- Lemon juice is a versatile cleaner and can be used in combination with baking soda or salt to inhibit the growth of some bacteria.
- Using a stronger cleaner is advised for cleansing surfaces that come in contact with raw meat.
Many of these natural cleaners can help reduce problems caused by other household pests as well. Wiping counters with vinegar can kill microbes as well as prevent pests such as ants and cockroaches finding food in your kitchen, without resorting to harmful pesticides. See our bulletins on ants and cockroaches for more information.
Antimicrobial Pesticides for Treating Mold, Bacteria, and Viruses
Potential Consequences of Using Antimicrobial Pesticides
Antimicrobial pesticides can be beneficial for protecting human health and are required in some institutional settings such as daycare centers, restaurants, and other food-handling establishments. If you are caring for an immune-compromised person or running a daycare center, proper disinfection or sanitation of surfaces is particularly important, and antimicrobial pesticides are an important tool. Nevertheless, there are adverse effects associated with their use, such as:
- The overuse of some antimicrobial agents may be a factor contributing to the development of resistant bacteria, so use only when needed.
- Because many of these products are available as aerosol sprays, exposure through inhalation is possible and can cause respiratory and eye irritation and exacerbate asthma.
- Many of these products are effective at sanitizing and disinfecting because they are oxidizing agents or are strongly acidic or basic. These characteristics result in hazards from spills on skin or in the eyes, or via inhalation.
Be sure to follow the label instructions carefully and read all warnings.
Types of antimicrobial pesticides
Antimicrobial pesticides are used to destroy or stop the growth of microorganisms such as bacteria, viruses, and fungi. They are designed to be used on inanimate objects only and can be found as sprays, liquids, concentrated powders, wipes, and gases (mostly for hospital use).
There are several different types of anti-microbial products and it is important to know their intended use. The US EPA has very specific definitions for each one:
- Cleaner: A product that physically removes debris from the surface.
- Sanitizer: A product that kills 99.9% of the germs identified on its label.
- Disinfectant: A product that kills nearly 100% of the germs identified on its label. Destroys most pathogens but not bacterial spores.
- Sterilizer: A product that destroys all microorganisms, including bacterial spores.
The Centers for Disease Control (CDC) further classifies disinfectants as high, intermediate, and low level disinfectants, which has to do with which particular microorganisms it inactivates and the concentration at which it is active.
The antimicrobial activity of the product is affected by the concentration of the active ingredients and the dwell time.
- Dwell time: The amount of time that the product must remain on the surface for optimum antimicrobial activity. Typically included on the label.
- Concentration of active ingredients: The concentration of an active ingredient varies from product to product, so read the label to determine if a product can be used as a disinfectant or only as a sanitizer.The percent of the active ingredient and the inert ingredients in a product may also change the hazards associated with a particular product.
The US EPA registers antimicrobial products and ensures that labels may not make claims about their effectiveness that are not supported by data. They have also compiled a list of registered products that are effective against specific pathogens, including tuberculosis bacteria, HIV-1 virus, and hepatitis C. For the lists of these products and others, see their website on Selected EPA-Registered Disinfectants.
The following table provides the hazards associated with specific active ingredients. Products may contain other ingredients or more than one active ingredients, so be sure to carefully read the label for any additional or different hazard warnings. According to the EPA, there are approximately 275 active ingredients that are used in antimicrobial products, so we have provided a partial list of some of the types of products you may encounter.