We've been conditioned by advertising to believe that if something smells clean, it is clean. So it's no surprise that chemical air fresheners have become a staple in schools across the country. They are typically used in locker rooms, lavatories, storage closets, lounges, and even classrooms.

Among the most commonly used chemicals in commercial air freshening products are phthalates (pronounced "thay-lates") — a class of hazardous chemicals known to cause hormonal abnormalities, birth defects, and reproductive problems. An independent test of fourteen common air freshening products conducted by National Resources Defense Council showed phthalates were present in all but two of them, including many listed as "unscented."

Other chemicals commonly found in air fresheners (and scented candles) can trigger asthma attacks, interfere with endocrine systems, and even increase the risks of cancer in some individuals. Children and pregnant women are particularly vulnerable to these toxins.

Good ventilation and good housekeeping are still the best way to keep things smelling fresh and clean. Scrubbing with detergent and hot water and then deodorizing using white vinegar or baking soda can eliminate many odor problems. There are also many new products on the market using essential oils and plant extracts to create pleasant but non-toxic scents.

Note: chemically-sensitive individuals may even have adverse reactions to natural scents.