Mold can produce a variety of odors, and in some cases, it may smell like sewage. There are a few reasons why mold might give off a sewage-like smell:
Types of mold that smell like sewage
Certain types of mold are more likely to produce sewage-like odors. These include:
- Stachybotrys chartarum – Also known as “black mold,” this toxic mold is known for its foul, musty odor that some describe as smelling like sewage.
- Aspergillus – This common mold can produce a stench similar to rotten eggs or sewage when it grows indoors.
- Fusarium – A pink mold that is often found in showers and damp areas, fusarium can emit a strong sewage or fishy odor.
So if you detect a sewage-like smell in your home, it could be due to the presence of stachybotrys, aspergillus, fusarium, or another type of mold.
Causes of sewage-like mold odors
There are a few reasons why mold might produce an odor reminiscent of sewage:
- Organic matter – Mold often grows on decaying organic matter. The odor of decomposition can be similar to that of sewage.
- Sulfur compounds – Some molds produce sulfur compounds like hydrogen sulfide as a byproduct, which has a distinct sewage smell.
- Anaerobic conditions – When mold grows in anaerobic (low oxygen) conditions, like behind walls or under materials, it can generate foul odors resembling sewage.
So if mold is growing undetected in your home, such as behind drywall or under carpets, the anaerobic conditions can cause it to emit an especially unpleasant sewage-like smell.
Health risks of sewage-smelling mold
Inhalation of molds that smell like sewage can potentially pose health risks including:
- Allergic reactions – Symptoms may include nasal congestion, eye irritation, coughing, wheezing, and skin rashes.
- Asthma attacks – Mold exposure can trigger asthma attacks in those with sensitive airways.
- Respiratory problems – Sewage-smelling molds can cause upper respiratory tract infections, shortness of breath, and worsen COPD symptoms.
- Headaches, fatigue, and nausea – Toxic molds like stachybotrys may cause flu-like symptoms from inhalation of spores and mycotoxins.
Prolonged exposure to foul-smelling molds could potentially lead to dangerous health consequences. Seek medical help if you experience concerning symptoms after inhaling moldy odors.
Mold vs sewage: key differences in smell
While there may be some overlap, mold generally has a mustier, stale odor compared to raw sewage. Here are some key differences:
| Mold | Sewage |
|---|---|
| Musty, stale, earthy smell | Ammonia-like, rotten egg odor |
| Smell intensifies after rain or water damage | Persistent odor, not weather dependent |
| Associated with moisture, humidity | Associated with septic systems, sewer pipes |
Pay attention to when and where an odor arises to help decipher if it’s more likely caused by mold growth or a sewage leak.
How to get rid of sewage-smelling mold
If the mold odor persists after cleaning, you may need professional mold remediation. But here are some initial DIY steps:
- Find and fix the moisture source allowing the mold to grow.
- Clean surfaces with detergent and water to remove mold.
- Use fans or dehumidifiers to dry out the area fully after cleaning.
- Discard any porous materials like drywall or carpet that have heavy mold growth.
- Use protective gear like masks, gloves, and goggles when cleaning mold.
- Consider using mold killing products like bleach, vinegar, or tea tree oil.
- Keep the area well-ventilated.
Removing the underlying moisture issue is key to getting rid of sewage-smelling mold long-term.
When to seek professional mold removal
Contact a professional mold remediation company if:
- Mold covers a large area greater than 10 square feet.
- You have a mold allergy or sensitivity.
- DIY clean up attempts are unsuccessful.
- The mold returns quickly after removing it.
- You suspect you have “toxic” black mold like stachybotrys.
- Mold is growing inside HVAC systems, under materials, or in hard to reach spots.
Professionals have the proper equipment, expertise, and products to fully rid a home of persistent, hazardous molds. They can also identify and fix any environmental issues causing the mold growth.
Conclusion
In summary, certain types of mold can produce a sewage-like odor due to decomposition processes and sulfur compounds. Stachybotrys, aspergillus, and fusarium molds are most associated with sewage odors. While similar, mold tends to smell mustier compared to raw sewage. If mold smells like sewage, take steps to remove it to avoid potential health issues. Seek professional help for large or recurring mold problems.