Sharing What We Know
This has been a complex situation and the community has had many questions. This page is designed to answer the most common concerns and FAQs with the most accurate and up-to-date information we currently have available.
If you don’t see your question answered, please use the form below to reach out – we’re here to help.
Frequently Asked Questions (FAQs)
Understanding the Occupied Building Indoor Air Quality Report
Why was another indoor air quality report conducted at Covington Middle School?
In order to take full advantage of the subject matter expertise of our hired partners, and to provide the best possible outcomes for our community, the Alleghany Highlands School Board committed early on to implementing all feasible recommendations provided by third-party partners supporting our response to the January 31 incident. Conducting another air quality study while the building was fully occupied was a recommendation in the Facilities Dynamics Engineering Mechanical Systems Assessment Report issued March 3, 2025.
What was tested in the building?
The occupied building air quality assessment focused on four key indoor air quality indicators:
- Carbon dioxide (CO₂)
- Carbon monoxide (CO)
- Temperature
- Relative humidity
The assessment used standard industry benchmarks to evaluate air quality, ventilation, and environmental comfort inside the CMS building.
What did the testing find?
The testing confirmed that the building met all OSHA workplace air quality standards.
Carbon Monoxide
No elevated carbon monoxide (CO) levels were detected anywhere in the building.
These test results are consistent with Virginia Department of Health’s early February 2025 investigation at CMS which was officially closed on February 1, 2025.
Note: The Virginia Department of Health’s larger community-wide investigation into elevated carboxyhemoglobin test-results is ongoing. More information about that effort is available on their website at https://www.vdh.virginia.gov/roanoke/news-room/.
Carbon Dioxide
Carbon dioxide readings ranged from 384ppm (very low) to 3157ppm (elevated but not dangerous) throughout the building. While these levels fall well below the OSHA permissible exposure limits of 5000 ppm over an 8-hour period, these levels did show that fresh air was not flowing equally through all parts of the building. Notably, some of the rooms on the second and third floor of the building that had reported unusual odors correspond with rooms that registered higher CO2 levels when occupied.
While these levels ARE NOT considered dangerous to occupant health, they do point to an opportunity to improve building ventilation in order to make these rooms more comfortable for staff and students.
With this new information, AHPS has prioritized upgrading its ventilation system to increase the flow of fresh aid throughout the building. Modern air handling technology has made tremendous efficiency gains in recent years, so an entirely new system (Tempmaster by JCI 100% Make-up Air unit) has been ordered to replace the older RTU-4 unit. It will be installed upon arrival.
In the meantime, window units have been ordered and will be installed as soon as possible to improve air flow in affected classrooms more immediately.
Temperature
Temperatures were all in typical ranges and indicated no issues with heating and cooling controls.
Relative Humidity
Relative humidity was not elevated. This is consistent with previous building spore testing (mold testing) which also did not raise any concerns.
The full report is available for download and review in its entirety here: Air Quality Report
Was anything dangerous found in the latest occupied indoor air quality testing report?
No. OSHA’s permissible exposure limit (PEL) in a building like ours is 5,000 ppm (taken as an average over an 8-hour period). The readings inside our building averaged less than half of this OSHA permissible limit.
Was anything actionable found in the latest occupied indoor air quality testing evaluation?
While there was nothing dangerous reported based on the most recent air quality evaluations, the findings did identify an opportunity to improve building ventilation, especially in some of the classrooms on the second and third floor where unexpected odors had been reported.
Unlike carbon monoxide, which can be dangerous, carbon dioxide is a naturally occurring substance that is part of the natural human breathing process. All day and every day humans breathe in air, filter it, keep the oxygen, and breathe out carbon dioxide. That is why when a building is fully occupied, CO₂ levels are at their highest.
Accordingly, the CO₂ levels in some classrooms did exceed current industry targets for CO₂ concentrations. These results indicate an opportunity to improve air flow and ventilation inside the building in order to improve overall indoor air quality. This is not an uncommon occurrence for older buildings as air handling technology and building design techniques have advanced significantly over time. The building industry’s indoor air quality targets have naturally also evolved to keep pace with new equipment capabilities and widespread availability.
The current American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) target for CO₂ concentrations in an indoor air space are approximately 1000-1200 ppm or about 700 ppm above outdoor air, which generally ranges from 300-500 ppm. Many, but not all, of the spaces tested inside CMS meet these targets. The goal is to take advantage of technology advancements and upgrade our systems.
Are there any outstanding questions?
Yes. We still do not know the source of the unpleasant, “ammonia” or “cat-urine-like” odor, as reported on the third floor. At this stage, the building has been extensively tested for air quality, mold, vermin, and plumbing issues. No odors were detected by environmental assessors during the most recent testing period. A previous third-party report from ECS, indicated that the odor was most likely “occupant-produced.”
However, in an effort to leave no stone unturned, in the coming days, AHPS will conduct one last test to determine more conclusively if there is any air escaping from the sewer system and finding its way into the building. The plumbing system has been checked by multiple parties already with no significant findings but a “smoke test” is considered the most comprehensive way to rule this out this concern and has been scheduled. The results of that test will also be released when available.
If that test reveals any issues that need to be addressed, the Alleghany Highlands School Board has committed to take immediate action but, if it does not, AHPS will have exhausted available investigative options and may never know the source of the original odor. That said, school system leadership is confident that the new ventilation and air handling system upgrades will likely remedy the problem moving forward.
Will other buildings be tested or upgraded?
We know that many of our facilities are older and need updates. AHPS has an existing capital improvement plan publicly available at https://www.ahps.k12.va.us/school_board/strategic_comprehensive_capital_improvement_plans. This document helps track building needs and prioritize capital improvements.
The extensive facility testing at CMS has been an investigatory pursuit and a direct prioritized response to very specific and very serious occupant health concern that has now been resolved.
However, in the coming weeks, the Alleghany Highlands School Board will most certainly consider what has been learned from this incident more broadly and weigh additional options and opportunities districtwide.
School Operations and Impact Questions
Will students stay in-person at Covington Middle School?
Yes. Based on the results of all air quality testing to date and well-aligned guidance from multiple third-party experts, the Alleghany Highlands School Board has determined that the building remains suitable for continued use in its current state.
While the school will work to lower CO₂ levels, current levels do not pose a health hazard and meet OSHA permissible exposure limit (PEL) guidelines.
When will the new ventilation system be ready?
The new rooftop air handler (Tempmaster by JCI 100% Make-up Air unit) is expected to be fully installed and functional prior to the fall 2025 semester.
Where can I find the previous FAQs and archived CMSincident.com website content?
CMSincident.com/transparency-archive is your one stop shop for all records related to this incident. If you are unable to find something you are looking for please let us know by emailing aphsinfo@ahps.k12.va.us.
I’ve submitted a question and haven’t yet gotten a response. What can I do?
We are aware of a backlog of community communications that still need response and apologize for any delays. We have received extensive and detailed community interest in this complex situation and have prioritized responding to the most frequently asked questions through this website in order to prioritize sharing the most important information with everyone in our community at the same time. We are continuing to work through individual email communications and call logs and ask for your patience as we do so.
In the meantime, please do not submit the same questions more than once as that will not expedite your response and will slow down response times for others. Instead, we encourage everyone to check this website for the most complete, verified, and up-to-date information available at any time.
Thank you for your continued support as we have had to prioritize limited resources to keep students safe and learning while doing our best to remain open and transparent with our community.
Health & Safety Questions
Is elevated CO₂ dangerous for students or staff?
Not at the levels observed at Covington Middle School.
OSHA regulations kick in at 5,000 ppm. According to the Centers for Disease Control (CDC) CO2 is considered dangerous to life and health between 50,000 and 100,000ppm. The highest level observed at Covington Middle School was in the low 3,000 range initially and dropped to the 2,000 range when the recently repaired RTU-4 unit was activated.
CO₂ is a natural component of the air we breathe and is not toxic at the levels identified in the most recent air quality studies. However, general industry consensus is that ideal indoor air quality has CO₂ levels that typically register at or below 1200. AHPS is upgrading CMS air handling equipment to be able to achieve these new targets.
What is the difference between carbon monoxide and carbon dioxide? Does carbon dioxide (CO₂) cause elevated carboxyhemoglobin levels?
Carbon dioxide and carbon monoxide are completely different gases.
Carbon dioxide is a naturally occurring compound found in the air we breathe. Carbon monoxide (CO) is not naturally occurring. It is produced by incomplete combustion and can cause elevated carboxyhemoglobin (COHb) levels in the blood.
Carbon monoxide can bind to hemoglobin in human blood and cause elevated carboxyhemoglobin levels. Carbon dioxide (CO₂) does not bind to hemoglobin and does not cause CO poisoning or elevated COHb levels.
There is no evidence of current CO hazards in the building. CMS is not believed to be the source of exposure for anyone who may have had elevated carboxyhemoglobin test results in recent weeks.
What is being done to improve indoor air quality at CMS?
AHPS has ordered a full replacement of the third-floor rooftop air handler unit (the RTU-4), the system responsible for circulating fresh air through parts of the building. Upon arrival the new unit (a Tempmaster by JCI 100% Make-up Air unit), it will be installed and is expected to meet higher performance standards and significantly improve airflow and indoor air quality throughout the building. The full replacement will take several weeks and must be scheduled around student schedules. The project is expected to be completed before the start of the 2025–2026 school year.
In the meantime, temporary window units have been ordered and will be installed in select rooms upon arrival. Periodic air quality monitoring will continue to take place, and all staff are encouraged to continue to report concerns so, should they arise, they can be addressed quickly.
What do I do if my child has a new or ongoing health concern?
As always, anyone who believes they need medical attention should seek the care they need from a qualified health practitioner. All AHPS school nurses are supported by a dedicated school nurse coordinator in an expansion of services since consolidation. CMS also has a guidance counselor onsite who can provide extra support where needed.
If you have a concern specific to your child’s educational welfare or a health concern you feel the school system should know about, please contact CMS directly so that the administrative team can connect you with additional resources as appropriate.
Will air quality continue to be monitored?
Yes. AHPS will continue routine monitoring of CO₂ and ventilation performance in classrooms and other areas of the building. Additionally, carbon monoxide detectors will remain in all classrooms and in shared spaces and hallways throughout the building. These resources are helping us to ensure that conditions remain stable and that improvements are working as intended.