Red mold is any mold — a fungus growing in the form of a filamentous structure called a hypha — with a reddish color at some stage of its life. Many molds are red for all or part of their lives, and people interested in identifying a specific species will need to collect some information about its characteristics in order to identify it. In some cases, inspection in a lab is necessary, as sometimes the distinctions between mold species are difficult to make without experience and special equipment.
Fungi run the gamut from obnoxious growths developing in moist environments like bathrooms to beneficial molds used in the production of food products like fermented red rice colonized with Monascus purpureus, a red mold sometimes called “red yeast” because of the negative associations with mold. Molds tend to enjoy moist, warm environments with limited air circulation. Some do not like ultraviolet radiation, and will avoid sunny spaces, preferring dark and dim areas or locations with indirect light. Common areas to find red species include on tile grout, the undersides of houses, damp rooms, and on foods like bread, where the high moisture level and nutrients can cause molds to thrive, sometimes exploding into growth in a matter of days.
In many cases, red mold is not harmful, although it is advisable to avoid close contact with it. Foods on which it grows should be discarded unless they are fermented or specialty foods made in controlled conditions, where the type of mold is known. In environments like kitchens and bathrooms, molds can be removed with hot water and soap. Increasing air circulation, using heaters to dry the air, and promoting the flow of sunlight into a space can limit the recurrence of molds. Solutions like bleach sprays may also help.
Some types of molds can produce toxins, making people sick. If people are concerned about fungus they encounter in their homes, they can take a swab and take it to a lab for testing. A mycologist can examine the sample, determine what kind of mold is involved, and provide people with information on whether it is harmful. The specialist may also have tips for eliminating and suppressing growth to make sure molds will not come back in the future. It is important to remove it thoroughly before painting, applying new tile or linoleum, or engaging in other remodeling activities. If the mold is simply covered, it can grow under and behind the covering, and it will become a problem in the future.