Take your clothes out of the plastic bags and hang them on a clothesline or in your garage for 30 minutes. Perchloroethylene, a suspected carcinogen, is widely used to dry clean clothes and recent studies shows that people breathe low levels of this chemical in homes where dry cleaning in stored and when they wear dry-cleaned clothes, according to the EPA.

When guests come to stay, they may be bringing more than their luggage. It’s not uncommon for clothes, shoes and bags to carry residual allergens, such as pollen and pet dander, says Cunningham. To avoid a sneezing fit, put visitors’ coats and shoes in a closed-off room and after they leave, use a vacuum with a HEPA (high-efficiency particulate) filter or a double-layered bag.

“Changing furnace filters is one of the most overlooked items for homeowners,” says Cunningham. A clean filter helps reduce the amount of dirt and dust circulating in the air and also maximizes the efficiency of your furnace, saving your money on your heating bills. Standard one-inch filters should be changed once a month; others can sit for up to a year if they’re larger. When in doubt, look at the backside, says Cunningham. “If grey or brown debris has pushed through, it’s definitely time for a change.”

Even if they’re closed, these products can leak volatile organic compounds (VOCs), gases that can cause respiratory tract irritation, headaches, dizziness and more, according to the EPA. “The best thing to do is put them in sealed containers and store them outside in the garage or another area that has better circulation,” says Cunningham. The EPA also recommends throwing away old or unneeded cleaners—just don’t toss them straight in the garbage can. Communities often organize special days for the collection of toxic household wastes.

“We associate the smell of fresh paint with things that are new and good,” says Cunningham. “But it’s an irritant.” According to the EPA, paint strippers, adhesive removers ad aerosol spray paints contain methylene chloride, an organic compound that causes cancer in animals and is also converted to carbon monoxide in the body, which can trigger symptoms related to carbon monoxide exposure. Many paint supplies also contain benzene, a human carcinogen. If you’re repainting a room, use low-VOC paint and open windows or use an air purifier to ensure maximum ventilation. The EPA also recommends buying limited quantities of these products if you only use them occasionally so you don’t have to store them in your house.

With all these sneaky health hazards floating through your home, buying an air purifier seems like the obvious solution, right? Wrong. “Some portable purifiers actually emit ground-level ozone,” says Cunningham, which can cause shortness of breath, chest pain when inhaling deeply and wheezing and coughing. Unfortunately there is no easy way to figure out which products are non-ozone, so you’ll have to do little digging. If the store or dealer you’re buying it from doesn’t know, check the company’s website.

Next: House Plants for a Healthier Home