Mold is an environmental hazard that can cause concern among renters. Across the country, tenants have won multimillion-dollar cases against landlords for significant health problems—such as rashes, chronic fatigue, nausea, cognitive losses, hemorrhaging, and asthma—allegedly caused by exposure to "toxic molds" in their building.
If you suspect there's mold in your rental unit, learn what to look for and when your landlord might be liable. Even better, take steps to prevent or clean up mold before it becomes a problem.
Mold comes in various colors and shapes. The villains—with names like stachybotrys, penicillium, aspergilus, paecilomyces, and fusarium—are black, white, green, or gray. Some are powdery, others shiny. Some molds look and smell disgusting; others are barely seen—hidden between walls, under floors and ceilings, or in less accessible spots, such as basements and attics.
Mold often grows on water-soaked materials, such as wall paneling, paint, fabric, ceiling tiles, newspapers, or cardboard boxes. Humidity sets up prime growing conditions for mold. Buildings in the naturally humid climates of Texas, California, and the southeast have experienced more mold problems than residences in drier climates. But whatever the climate, mold can grow as long as moisture is present.
Mold is also among the most controversial of environmental hazards. There is considerable debate within the scientific and medical communities about which molds, and what situations, pose serious health risks to people in their homes. There is no debate, however, among tenants who have suffered the consequences of living amidst (and inhaling) mold spores.
Keep in mind, however, that most mold is not harmful to your health—for example, the mold that grows on shower tiles is not dangerous. It takes an expert to know whether a particular mold is harmful or just annoying. And it's very tricky to find out whether a person who has been exposed to mold has actually inhaled or ingested it. Although blood, urine, and other tests can be used to assess exposure to mold, these tests are often inconclusive.
With a few exceptions, landlord responsibilities regarding mold aren't clearly spelled out in building codes, ordinances, statutes, or regulations. (But, as explained below, landlords can be held responsible for mold problems even absent specific laws governing mold.)
No federal law sets permissible exposure limits or building tolerance standards for mold in residential buildings. A few states (including California, Indiana, Maryland, New Jersey, and Texas), and a few cities (including New York and San Francisco), have taken steps toward establishing permissible mold standards or guidelines and regulations for mold in indoor air.
To see whether your state is considering mold-related legislation that might affect residential rentals, you can search the National Conference of State Legislatures' Environmental Health State Bill Tracking Database. Check the "Indoor Air Quality—Mold" box in the "Topics" column, and check the box next to your state.
For local mold-related rules, contact your city manager, mayor's office or other local government department.
Even if your state or city doesn't have specific mold laws, your landlord could still be liable for a mold problem in your rental, as a result of landlords' responsibility to provide safe and livable housing. Depending on the situation, state law might give you options such as rent withholding if your landlord fails to fix a serious mold problem, or you might be able to file a lawsuit for mold-related health problems. A few states, such as Virginia, specify that maintaining mold-free premises is part of a landlord's duty to provide habitable housing. (Va. Code § 55.1-1220 (2023).)
Landlords in all states are responsible for maintaining fit and habitable housing and repairing rental property, and this extends to fixing leaking pipes, windows, and roofs—the causes of most mold. (Note that each state has its own definitions of what "habitable housing" is, and each state's law sets its own level of landlord responsibility. Some states have stricter habitability laws than others.) If the landlord doesn't take care of leaks and mold grows as a result, you might be able to hold the landlord responsible if you can convince a judge or jury that the mold has caused a health problem.
The liability picture changes when mold grows as the result of your own behavior, such as keeping the apartment tightly shut, creating high humidity, or failing to maintain necessary cleanliness. Tenants have some duties to maintain their rental unit, so when a tenant's own negligence is the sole cause of injury, the landlord is not liable. To avoid causing any mold problems, practice good housekeeping, such as ventilating your apartment.
Some landlords include clauses in the lease that purport to relieve them from any liability resulting from mold growth. At least one court has refused to enforce such a clause, ruling that to do so would be against public policy. (Hi-Tec Properties, LLC v. Murphy, 14 N.E. 3d 767 (Ind. App. 2014).) More cases from other parts of the country are sure to arise as mold litigation makes its way through the courts. Some states require landlords to disclose information about mold to tenants.
A smart landlord will try to prevent the conditions that lead to the growth of mold—and tenants should be the landlord's partner in this effort. This approach requires maintaining the structural integrity of the property (the roof, plumbing, and windows), which is the landlord's job. You can help by preventing mold problems in your home in the first place and promptly reporting problems that need the landlord's attention.
For more information on mold, including what it looks like, how to test for mold, the health effects of mold exposure, and how to clean up mold, check out the Mold section of the EPA website.