Can Black Mold Kill You?

Medically Reviewed by Melinda Ratini, MS, DO on May 26, 2023
Written by WebMD Editorial Contributors
4 min read

There are many types of black mold. Stachybotrys chartarum is usually the one referred to as " toxic mold." All molds can cause symptoms in people who are sensitive to or allergic to mold. But there is no reason to believe that black mold is any more dangerous than other types or colors of mold.

Stachybotrys chartarum is a common black mold. It can also be a greenish color. It grows on cotton, wood, and paper products. It sometimes produces toxic chemicals that are found in its airborne spores and fungus fragments. 

These are called mycotoxins and are dangerous if they're eaten. There's no link to inhaled Stachybotrys chartarum mycotoxins and deadly diseases. But there are risks for people with allergies, asthma, and other hypersensitivities.

There is no evidence that black mold causes symptoms such as fatigue, memory loss, an inability to focus, or a headache. These symptoms have been referred to as "toxic mold syndrome" but are largely due to media hype. Yet some people are allergic to mold. It should always be removed from your home.

Molds are an important part of our environment. They decompose dead plants and animals. All types of mold will grow if the conditions are right. Mold grows and spreads quickly in the right conditions, which include:

  • Moisture level (humidity) at or over 70%
  • Adequate food source (such as drywall)
  • Oxygen
  • Temperatures that range from 40 to 100 degrees F

Mold can grow anywhere in your house that provides these conditions. The most likely places mold will grow are:

  • Anywhere that there has been a water leak.
  • Damp rooms without adequate ventilation, such as bathrooms.
  • Basements where humidity tends to be higher.
  • Any areas with a lot of water condensation.
  • Any areas where flooding has occurred.

Mold can cause symptoms in people who are allergic to them or in people who are exposed for a long period of time or to a lot of mold such as farmers working with a large amount of moldy hay. The most common symptoms of mold exposure include:

Be careful if you have asthma. Mold exposure may trigger an attack. Symptoms of a mold-induced asthma attack can be any of the following: 

Protect yourself. You don't need to worry about having mold tested if you find mold in your house. But you should get rid of it no matter what type of mold it is. Take precautions to protect yourself before you attempt to remove mold.

Use an N-95 face mask to avoid breathing in mold spores. Wear gloves to protect your hands and goggles without ventilation holes to protect your eyes.‌

Find and destroy the mold. The most important part of removing mold is finding and removing its water source. Mold can't grow without moisture. Keep the following tips in mind when you're cleaning up mold:

  • Items that can't be dried quickly should be discarded if they show signs of mold or water damage. Porous items such as carpet, padding, drywall, and paper soak up moisture.
  • Do not paint or caulk over moldy surfaces. Remove the mold and dry the surfaces before you paint. Paint applied over mold will peel.
  • Use plastic sheeting to block an area with mold from the rest of your house and keep the spores from spreading.
  • Scrub hard surfaces with mold with detergent and water and dry them thoroughly.
  • Put any moldy items in a plastic bag before you take them out of the room to prevent mold spores from spreading.
  • Use a HEPA filter in your air conditioner and furnace to capture mold spores that may be airborne in your house.
  • Consult a specialist if you're not sure of the best way to clean a valuable or sentimental item.‌

Be careful with bleach. Take the following extra precautions if you're using bleach to clean mold:

  • Never mix bleach with any other household cleaner, especially any containing ammonia. Mixing bleach and ammonia will produce a poisonous gas that can kill you.
  • Make sure you read and follow the manufacturer's directions on bleach or any other cleaning product.
  • Open your windows and doors to let in fresh air when you're using bleach.
  • Wear rubber boots, gloves, and goggles to protect your skin and eyes from the bleach.

Controlling moisture is the key to preventing mold from growing in your home. The following tips will help stop mold from becoming a problem:

  • Keep the humidity in your house below 50%. Using an air conditioner or dehumidifier can help with this.
  • Make sure your house is clean, dry, and well-ventilated.
  • Fix any water leaks immediately.
  • Use ventilation fans in your kitchen and bathrooms.
  • Don't put carpet in rooms that are likely to become wet such as the basement, kitchen, or bathrooms.
  • Make sure wet floor mats are dried quickly.