I used to get a lot of question about how long it takes to test a home for radon. I really didn’t have an answer to that question, so I started to answer, “How long do you have?” The honest answer is that a result can be garnered within twenty-four hours. Most radon tests suggests that the test be done for forty-eight hours or longer. These tests will also tell you that if there is a reading that is less than a four pCi/L. What this means less than four picoCuries per liter of air. Madame Curie came up with the way to test for radioactivity. A Curie is a unit of radioactivity that is equivalent to 1 gram of radium per trillionth. According to the EPA, any reading should be taken action on. According to most health departments, less than a 4 pCi/L is acceptable and deemed not dangerous. The longer the test kit sits in the lowest part of the home, the better the reading. A false reading, meaning that the pCi/L is lower than it actually reads, happens when the test is done for less than ninety days. Since most people don’t want to wait to buy their dream home, for over three months, the testing is done in about two weeks, in most situations. The EPA has loosened up and agreed that there is little chance of radon poisoning occurring if the reading is at a concentration of lower than 4pCi/L, and that has become the standard for testing for radon in homes.