Product DescriptionHSI products are Environmentally Friendly. Our CoCheck Carbon Monoxide Detector Tester does not have HFC. Our products do not damage the Ozone layer and do not contribute to Global Warming. CoCheck Carbon Monoxide Detector Tester complies with both the Kyoto and Montreal Protocols and the California state requirements. CoCheck is 100% All Natural and Non-Flammable This product contains material found in the air we breath. Designed and packaged in a size that prevents any accidents. There is not enough CO in the product to produce any ill effects. It is safe, effective and works! The Perfect solution.