• There are a few varieties of white mold.mold on petrified wood image by MAXFX from Fotolia.com
  
  Mold is a variety of fungus that decays organic matter. Thousands of mold spores are floating through the air inside and outside of your home. They can become a nuisance and can cause health problems if left to grow extensively inside your home or if you work in a mold-infested area. Some varieties of white mold are more harmful than others and grow for different reasons and in different places.
  
  

Aspergillus

• Aspergillus is a common variety of mold. Depending on the genus of the mold it can appear grey, brown, yellow, green, black or white. Aspergillus can cause an allergic reaction and hay fever-like symptoms. It can also cause long-term health concerns, such as lung infections and the spread of toxins through the body. Those with susceptible respiratory systems are particularly at danger of long-term effects. Aspergillus commonly grows in walls, insulation, soil and clothing. It grows most often in areas that are damp and poorly ventilated.
  
  

Penicillium

• Penicillium is a common type of mold that was once used to discover the common antibiotic penicillin. This variety of mold is commonly found on food, such as older cheese or rotten fruit, and is not normally hazardous. The worst result of penicillium exposure is a mild allergic reaction. In most cases it is completely harmless. Cheese-makers often even encourage the growth of white mold on their fine cheeses. Nonetheless, those that are susceptible to respiratory difficulty--including the elderly, pregnant women, children or asthmatics--should avoid any mold consumption or discuss it with their doctor. In some cases, penicillium can grow on walls or insulation. The mold can appear blue, green or white.
  
  

Acremonium

• Acremonium most often grows in damp places, such as basements, laundry rooms, bathrooms or attics. It can also grow in areas that are not well-ventilated. The mold can appear grey, brown or white. It often grows in insulation, drywall or Sheetrock. It can cause reactions ranging from a mild allergic reaction to severe lung infections, depending on the extent of the growth and a person's exposure to it.