Radon Testing for Businesses and Commercial Buildings

If you own or operate a commercial building in Colorado — office, retail, light industrial, healthcare, daycare, school — radon testing is a different conversation than a homeowner test. The buildings are larger, employees and visitors spend longer hours in them, the regulatory framework is more specific (especially for schools and childcare), and the testing methodology shifts accordingly.

This page covers the basics for commercial Colorado property owners and operators: when to test, what standards apply, who's required to test, and what mitigation looks like at commercial scale.

EPA's 4.0 pCi/L action level was set for residential homes, where occupants spend the most time. Commercial workplaces have different exposure patterns:

• Office workers spend 40+ hours per week in a single building.
• Retail employees often work shifts in basement-level stockrooms.
• Healthcare facilities have patients with vulnerable lung health.
• Daycares and schools have children — for whom radon risk is a particular concern (higher respiration rates, developing lungs).

OSHA does not have a specific radon limit for workplaces (the closest analog is the radiation exposure limit for "general industry," which is far higher than typical home radon levels and rarely relevant). EPA's 4.0 pCi/L is the de facto standard.

For larger commercial buildings, testing follows the ANSI/AARST MAH (Measurement Protocols for Long-Term Devices) and SGM-MFLB-2023 standards.^[1] Key differences from residential:

• More tests per building. AARST protocols call for testing in roughly 10–30% of habitable spaces in a commercial building, depending on building size and use.
• Lowest occupied level. Same principle as homes — basements and ground floors first.
• Long-term tests preferred. For initial assessment and post-mitigation verification.
• HVAC awareness. Commercial HVAC systems can mask or dilute radon. Tests should be placed under representative HVAC operation.
• Licensed measurement. Same DORA + NRPP/NRSB credentials required for testers, plus AARST certification for commercial measurement.

Commercial testing typically runs $200–$500 per building for a small property, scaling up with building size.

Schools occupy a special category in radon policy. Colorado follows EPA recommendations for school radon testing:^[2]

• Every frequently occupied room in contact with the ground (including ground floor and basement classrooms, gyms, libraries, cafeterias, offices) should be tested.
• Initial testing should use a long-term measurement, or two consecutive short-term measurements.
• Action level of 4.0 pCi/L applies.
• The school district is responsible for testing decisions; CDPHE provides guidance.

Colorado does not have a state law requiring school radon testing, but EPA strongly recommends it. Many Colorado school districts have testing programs in place.

Childcare facilities licensed in Colorado are regulated by the Colorado Department of Early Childhood. Radon testing isn't currently a licensing requirement, but:

• EPA recommends radon testing in childcare facilities given child vulnerability to radon exposure.
• Many Colorado childcare facilities test voluntarily.
• Liability considerations: a daycare in a building with known elevated radon faces meaningful exposure risk if a child later develops radon-related lung disease.

Childcare operators in Colorado are well-advised to test annually or biennially, document results, and mitigate if levels exceed 4.0 pCi/L.

For office buildings, retail centers, and other multi-tenant commercial properties:

• The property owner or building manager typically arranges testing for common areas.
• Individual tenants can request testing for their leased spaces; tenant rights vary by lease terms.
• Testing follows AARST SGM-MFLB-2023 standards for the building scale.
• Mitigation responsibility usually rests with the property owner unless the lease assigns it to the tenant (uncommon).

Commercial mitigation uses the same principles as residential — sub-slab depressurization, sub-membrane for crawlspaces — but at building scale. Practical differences:

• Multiple suction points are the norm. A 10,000 sq ft building typically needs 4–8 suction points.
• Larger fans or multiple fans — often industrial-grade equipment rather than residential RadonAway/Fantech models.
• HVAC integration. Commercial HVAC affects building pressure; mitigation system design accounts for it.
• Building permits. Commercial mitigation work requires standard commercial building permits in Colorado Springs through Pikes Peak Regional Building Department.
• Cost. Commercial mitigation typically starts at $4,000–$8,000 for small buildings (under 5,000 sq ft) and scales up to tens of thousands for larger facilities.

1. Hire a DORA-licensed, AARST-certified measurement professional for commercial radon testing.
2. Walkthrough and test plan. They identify the rooms to test and plan placement.
3. Long-term measurement over 90+ days (or 2 short-term measurements 1–2 weeks each).
4. Report and review. Result interpreted against EPA 4.0 pCi/L action level.
5. If above 4.0 pCi/L: mitigation design begins. For larger buildings, expect a 2–4 month timeline from test completion to system commissioning.