Radon is an invisible gas that can affect any home. Knowing what safe radon levels are essential for homebuyers in Colorado. In this blog, we will walk you through the EPA action level, local radon zones, and testing options to help you make an informed decision on your home purchase.
What is Radon and Why It Matters
Radon is a naturally occurring radioactive gas that comes from the breakdown of uranium in soil and rock. You can’t see it, smell it, or taste it, but prolonged exposure can increase the risk of lung cancer.
For home buyers, understanding radon is crucial because it can accumulate in basements, crawl spaces, and even main living areas if the home isn’t properly ventilated. Knowing safe radon levels gives buyers the confidence to protect their health and make informed decisions.
Understanding Radon Levels: Safe vs. Unsafe
The Environmental Protection Agency (EPA) sets an action level of 4 picocuries per liter (pCi/L) for indoor radon. Levels below this are generally considered low risk, while anything above warrants mitigation. Colorado is divided into three radon zones to indicate risk:
- Zone 1: Highest potential levels – includes cities like Boulder and Fort Collins. Homes here are more likely to exceed the EPA action level.
- Zone 2: Moderate potential – Denver and surrounding suburbs typically fall here. Radon can still be a concern, so testing is recommended.
- Zone 3: Low potential – some rural areas see minimal radon risk, but testing is still the safest approach.
Even homes in Zone 2 or 3 can occasionally have elevated levels, so testing is always the best practice. Safe radon levels mean knowing where your home stands and taking action if numbers are above the recommended limit.
Radon in Colorado: What Buyers Should Know
Radon levels can vary from home to home, even within the same neighborhood. Denver homes often fall in the moderate range, but seasonal changes, soil conditions, and foundation type can influence indoor radon. In Boulder and Fort Collins, the likelihood of higher readings increases, reflecting their Zone 1 classification.
For buyers, this means a home inspection or radon test during the purchasing process can provide clarity and peace of mind. Knowing the potential for elevated radon allows buyers to plan for mitigation if needed.
Testing Your Home for Radon
Testing is simple and effective. Short-term tests last 2–7 days and give a quick snapshot, while long-term tests track levels over several months for a more accurate picture.
Many buyers include radon testing as part of the home inspection process, especially in Denver, Boulder, and Fort Collins. By testing early, buyers can see whether radon levels are safe or if mitigation steps are necessary.
Mitigation Options
If a home tests above the EPA action level, radon can be reduced through professional mitigation systems. These often involve venting radon from below the foundation to the outside, preventing accumulation inside the living space.
Professional mitigation is reliable, non-invasive, and gives buyers confidence that their new home is safe. Knowing safe radon levels and having a plan in place ensures that homeowners can enjoy their space without worrying about hidden risks.
The Bottom Line on Safe Radon Levels
Safe radon levels in Colorado homes vary depending on location, construction, and soil conditions. Zones 1–3 help illustrate potential risk, but testing is the only way to know a home’s actual radon levels.
Homebuyers should prioritize radon testing as part of the home-buying process. Understanding these levels, and knowing mitigation options exist, gives buyers the tools to protect their health and make smart, informed decisions.
