As if that weren't enough, 95 percent of synthetic compounds in scent are sourced from "petrochemicals" – substances linked to cancer, birth deformities, nervous system disorders, asthma, and environmental allergies. The other 5 percent are natural ingredients such as flower petals, amber resin, and even animal bones. Bath and body products can contain chemicals known as phthalates. These chemicals can be found in plastic toys, cosmetics, and fragrance products. They have been shown to break down into smaller particles that are able to enter the human body through the lungs or through pores in skin. The American Chemistry Society has said that there is some evidence that these chemicals may affect the development of reproductive organs in animals given large amounts over a long period of time. In addition, paraffin wax used in candle making contains hydrocarbons that may lead to cancer if inhaled for long periods of time. In fact, studies have shown that people who make their own candles using paraffin wax have higher rates of lung cancer than average. This is because they don't ventilate the rooms in which they burn candles so smoke goes straight into the air instead of escaping out the window or through an open door! Finally, mineral oils used in lubricants can solidify at low temperatures, causing problems with car engines.