What is the source of the indoor-air concern, and which observation, test or qualified response can answer the next question?
Start with the actual building, activities, moisture and fuel-burning equipment. Use the right test for the pollutant, address sources and water problems, and coordinate ventilation with outdoor conditions. Retain measurements and the evidence that a proposed correction worked.
Evidence checked October 16, 2026 (America/Denver). Version 1.0. Desk review; no hands-on testing.
What this guide helps you do
For planning routine indoor-environment observations and appropriate assessment. It does not diagnose illness, certify air as safe, prescribe remediation or authorize disturbance of suspected asbestos, lead, concealed mold or fuel equipment. An active CO alarm requires immediate action.
Make the urgent response clear
If a CO alarm sounds, CPSC directs people to move outside to fresh air, call emergency services or 911, and stay out until responders permit reentry. Do not search the house for the source first. Keep that response with the household emergency plan and actual alarm instructions. Routine investigation of a stain or stuffy room is a separate task. No alarm test or quiet sensor establishes that every indoor hazard is absent; CPSC notes that a test button does not verify sensor accuracy. Source: CPSC carbon-monoxide prevention and alarm response.
Create a dated building and activity record
Note where concerns occur, when they appear, recent products or renovation, water events, odors and the operation of cooking, heating or ventilation equipment. Keep observations separate from diagnoses. Identify installed equipment and available service records without opening hazardous or concealed areas. Ask occupants about recurring patterns and take personal health concerns to an appropriate clinician. The purpose of this file is to help the right assessor choose meaningful questions and tests, not to prove a cause from an odor or symptom alone.
Match the control to the source
EPA separates reducing pollutant sources, bringing in suitable outdoor air and filtering particles. Check the actual ventilation arrangement; ordinary recirculating HVAC airflow does not necessarily supply outdoor air. Consider outdoor smoke and other pollution before opening windows. A particle cleaner is not a universal gas-removal system or a substitute for radon mitigation. Ask a qualified person how a proposed control will work for the actual pollutant and building, and keep manufacturer care instructions with any equipment. Source: EPA indoor-air improvement framework.
Find and correct the water problem
EPA explains that mold can recur when cleanup leaves the moisture problem unresolved. Record visible dampness and the history of leaks and repairs. Ask for appropriate help when the water may be contaminated, HVAC contamination is suspected, hidden damage is possible or health concerns affect the work. Do not use the guide’s general area example as a universal permission to do cleanup. Retain the cause assessment, correction and follow-up observations; a new finish or a cleaned surface does not itself demonstrate that the water source was corrected. Source: EPA home moisture and mold guide.
Use a real radon result and the right protocol
A regional map cannot determine the radon level in an individual home. Follow the actual approved device or qualified measurement protocol for the purpose of the test, including placement, duration and conditions. EPA recommends fixing at 4 pCi/L or more and considering fixes between 2 and 4 pCi/L; it does not identify a no-risk boundary. CDPHE’s general and kit-specific placement sections need to be matched to the actual purpose and device. Keep the result, units, protocol and follow-up recommendation together. Source: EPA radon action guidance with Colorado testing pathway.
Verify the correction and leave a useful handover
Before buying a device or commissioning work, agree what the assessment is meant to establish and what follow-up will show. Keep the original report, limitations, corrective work, actual settings or maintenance instructions and next review. For CO-alarm placement, use the actual manufacturer instructions and local fire/building requirements; the captured CPSC pages differ on a basement exclusion, which remains unresolved here. Do not use that ambiguity to remove existing protection. Leave the file where another occupant can find both the routine care plan and urgent response.
A pathway to practice
- Describe the concern: Building, activity, moisture, equipment
- Choose the right assessment: Actual pollutant and test purpose
- Correct and verify: Source, water, ventilation, follow-up
- Keep care and response usable: Records, manuals, maintenance, handover
Resources and their limitations
EPA indoor-air improvement framework
Use it for: Identify a pollutant source and the appropriate control instead of assuming one device solves every problem.
Access and cost: Public reference freely readable; tests, equipment, professional services and improvements may cost extra.
How to use it: Read Source Control, Improved Ventilation and Air Cleaners together; check outdoor air before opening the home and retain actual system instructions.
Evaluation and limits: No pollutant, air cleaner, ventilation rate, health condition or HVAC system measured. A particle filter does not establish protection against gases or radon; linked products and technical documents not audited.
Alternatives: Qualified indoor-environment/building assessment; actual local health authority; the radon, moisture and CO sources below.
Open EPA indoor-air improvement framework
EPA home moisture and mold guide
Use it for: Connect recurring mold to the water problem and recognize circumstances needing experienced help.
Access and cost: Public reference freely readable; tests, equipment, professional services and improvements may cost extra.
How to use it: Read Mold Basics, Mold Cleanup and Hidden Mold with the actual circumstances. Seek experienced help for contaminated water, suspected HVAC contamination or uncertain scope.
Evaluation and limits: No mold, moisture source, hidden assembly, illness or cleanup assessed. Generic area cutoffs are not a universal DIY clearance. Chemical mixtures, demolition and cleanup procedures are not reproduced as instructions.
Alternatives: Qualified moisture/remediation professional; treating clinician for personal health concerns; building-envelope guide.
Open EPA home moisture and mold guide
EPA radon action guidance with Colorado testing pathway
Use it for: Keep the actual test result, purpose and follow-up distinct from a regional map or a no-risk claim.
Access and cost: Public reference freely readable; tests, equipment, professional services and improvements may cost extra.
How to use it: Follow the actual approved device instructions or qualified measurement route. Record purpose, location, conditions, duration, units and result; obtain appropriate follow-up advice.
Evaluation and limits: Existing resource and three scoped claims rechecked against EPA and CDPHE. No test, device, professional, rental-law provision, price or mitigation design verified. CDPHE contains generalized and kit-specific placement sections; resolve the exact purpose and protocol with the provider. No threshold is a guarantee of safety.
Alternatives: Actual state radon program and qualified measurement/mitigation professional; original device instructions.
Open EPA radon action guidance with Colorado testing pathway
CPSC carbon-monoxide prevention and alarm response
Use it for: Plan fuel-appliance maintenance, actual alarm care and immediate response to an alarm.
Access and cost: Public reference freely readable; tests, equipment, professional services and improvements may cost extra.
How to use it: Read alarm testing, installation and response sections with the actual model manual and local requirements. For an alarm, move outside, call emergency services and wait for permission before reentry.
Evaluation and limits: No alarm, appliance, sensor accuracy or home placement tested. The separate CPSC alarm page excludes certain basements while the Q&A says every level; no blanket basement exemption is adopted. Older mortality statistics are not current counts.
Alternatives: Manufacturer instructions, local fire/building authority and qualified appliance service; emergency responders for an active incident.
Open CPSC carbon-monoxide prevention and alarm response
Checklist
- Urgent CO response and actual alarm instructions available
- Activities, moisture and equipment observations dated
- Source control, suitable ventilation and filtration distinguished
- Water source and cleanup scope assessed appropriately
- Radon test purpose, protocol, result and follow-up retained
- Correction evidence, maintenance and handover recorded
Related guides
Building design and space planning (SG-D08-S02); Owner-building and project management (SG-D08-S04); Roofs, foundations and building envelopes (SG-D08-S06); Codes, permits and inspections (SG-D08-S08); Insulation and weather sealing (SG-D09-S01); Heating choices and wood heat (SG-D09-S02); Cooling, shade and ventilation (SG-D09-S03); Household energy assessment (SG-D09-S04).
From the Whole Earth registry to current practice
Spring 1969 Your Engineered House (PDF page 24, printed page 22; WE69S-E046/WE69S-L038) treats light, heat, ventilation and living conditions as design questions. The page was visually reviewed. Modern radon, CO, moisture and pollutant controls are separately sourced; the historical review supplies no current indoor-air safety standard.
Whole Earth Spring 1969 archive edition
Sources and review notes
No pollutant, home, test, sensor, illness or remediation was assessed. A universal basement alarm-placement exception is held unresolved and is not an instructional dependency. Existing radon records were rechecked. Historical ventilation questions do not establish modern pollutant control.
