House dust is now recognized as one of the most significant sources of childhood exposure to toxic substances. Studies have shown that house dust can contain a chemical soup including low levels of flame retardants, phthalates, organotin compounds, metals like lead, mercury and arsenic, pesticides, alkylphenols and perfluorinated compounds. Some of these chemicals are tracked in from outdoors but most originate from normal use and simple wear-and-tear on many different consumer products. Particularly for young children, activity such as crawling on the floor, hand-to-mouth activity, and putting toys or other objects in their mouths, increases their exposure. Many people find it surprising that very small amounts of these contaminants are found in house dust with higher levels in dryer lint and in the vacuum cleaner bag.