A lot of U.S. EPA lifetime safety and security requirements for health hazards are developed based upon a 1 in 100,000 threat of fatality. Most scientists agree that the danger of fatality for radon at 4 pCi/L is about 1 in 100. At the 4 pCi/L EPA action guideline level, radon lugs about 1000 times the threat of fatality as any type of various other EPA carcinogen. It is very important to keep in mind that the activity level is not asafe degree, as there are no "risk-free" degrees of radon gas.