What “Investigated” Actually Requires

“Unfounded”

Seven categories of evidence contradict that characterization:

1. FLIR thermal imaging — documented elevated surface temperatures on the FSK-taped ductwork inside the unit, consistent with conditions that accelerate adhesive off-gassing.
2. IoT sensor data — continuous environmental monitoring showed anomalous temperature and humidity patterns correlating with symptom onset.
3. Physician documentation — Dr. Fabi provided two letters documenting chemical exposure symptoms consistent with VOC inhalation, including respiratory distress and neurological effects.
4. Ambulance transport — EMS was called to the unit for acute exposure symptoms. The responding crew was also affected.
5. SERVPRO refusal — SERVPRO inspected the unit and declined the remediation job, stating it exceeded residential scope.
6. Three documented re-exposures — the tenant experienced additional exposure events upon returning to or near the unit, each time triggering the same symptom pattern.
7. No testing by the building — at no point did the building or its management company produce air sampling results, material safety data sheets, instrument calibration records, or any documentation of a methodological investigation.

The word “investigated” without methodology, instrumentation, or results is not an investigation. This page explains what a competent one looks like.

What Is a VOC Investigation?

Volatile organic compounds (VOCs) are chemicals that evaporate at room temperature. They are found in adhesives, sealants, paints, building materials, cleaning products, and manufactured goods. When trapped indoors, they accumulate in breathable air and can cause acute and chronic health effects ranging from eye and respiratory irritation to neurological impairment and organ damage.

Identifying that someone is experiencing symptoms is not the same as identifying what caused them. A VOC investigation is the structured process of tracing symptoms back to a specific source through a specific pathway. That distinction — between symptom identification and source attribution — is what separates a medical observation from an environmental conclusion.

Source attribution asks four questions in sequence:

• Source: What material or substance is releasing the compound?
• Pathway: How does the compound travel from the source to the breathing zone?
• Receptor: Who is exposed, at what concentration, and for how long?
• Attribution: Can the observed health effects be linked to that specific source through that specific pathway, to the exclusion of other plausible explanations?

A competent VOC source attribution requires seven elements:

Each hypothesis generated during the investigation must be evaluated against five criteria:

• Temporal consistency: Does the timeline of the proposed source match the timeline of symptoms?
• Spatial consistency: Is the proposed source physically connected to the exposure location?
• Plausibility: Does the proposed mechanism match established science for that compound and those conditions?
• Measurement support: Do environmental readings confirm or contradict the hypothesis?
• Alternative exclusion: Have other explanations been investigated and ruled out with evidence, not assumption?

An investigation that skips any of these steps has not reached a conclusion. It has reached an opinion.

How Air Moves in High-Rise Buildings

Air movement in a high-rise building is governed by three forces: wind pressure on the exterior envelope, temperature differences between inside and outside air, and mechanical systems (HVAC, exhaust fans, dryers). Understanding these forces is not optional in a VOC investigation — they determine the pathway between any source and any receptor.

Pressure differences drive airflow. Air always moves from higher pressure to lower pressure. In a building, these pressure differences are created by:

• Wind: The windward face of a building is pressurized; the leeward face is depressurized. Upper floors experience stronger wind effects.
• Temperature (stack effect): In warm weather, cooled indoor air is denser than outdoor air. In a high-rise, this creates a downward pressure pattern — outdoor air enters at upper floors and exits at lower floors. In cold weather, the pattern reverses: warm indoor air rises through elevator shafts, stairwells, and utility chases, pulling outdoor air in at the base.
• Mechanical systems: Exhaust fans, bathroom vents, kitchen hoods, and HVAC systems all create pressure imbalances. Any device that removes air from a space without replacing it creates negative pressure in that space.

Stack effect in high-rise buildings is a dominant force. Warm air is less dense than cool air, so it rises. In a tall building, this creates a continuous vertical draft through any connected vertical shaft — elevator shafts, stairwells, utility chases, plumbing stacks, and wall cavities. The taller the building, the stronger the effect. The result is that air from lower floors, garages, mechanical rooms, and common areas is drawn upward through the building’s structure, carrying whatever that air contains.

Single-hose portable air conditioners create negative pressure. A single-hose portable AC unit exhausts hot air through a window hose. That air must be replaced. The replacement air is pulled from wherever it can enter the unit — and the unit does not choose clean air over contaminated air. It draws from whatever pathway offers the least resistance.

The U.S. Department of Energy has documented this effect. In a 2016 Federal Register rulemaking (81 FR 35242), DOE noted that single-hose portable air conditioners create negative pressure that draws infiltration air from outdoors, adjacent spaces, and building cavities, reducing their effective cooling efficiency by 20–40% compared to dual-hose units. The energy penalty exists precisely because the replacement air is uncontrolled.

Where does replacement air come from when a single-hose AC creates negative pressure in a sealed high-rise unit?

• Hallway corridors — under the entry door, through gaps in the door frame
• Wall cavities — through electrical outlets, plumbing penetrations, and unsealed construction joints
• Neighboring units — through shared walls, floors, and ceilings via any unsealed penetration
• Vertical shafts — elevator shafts, stairwells, trash chutes, and utility risers connected to the unit’s floor
• Below-grade spaces — parking garages, mechanical rooms, and storage areas connected through the building’s vertical structure

This is why airflow analysis is essential in any high-rise VOC investigation. A single-hose portable AC does not just cool a room — it turns the room into a low-pressure zone that actively draws air from every connected space in the building. If any of those spaces contains a VOC source, the AC becomes the mechanism of exposure.

Tapes, Sealants, and Off-Gassing

Building tapes and sealants are not inert. They contain solvents, plasticizers, and adhesive compounds that off-gas — meaning they release volatile chemicals into the surrounding air as part of their normal curing and aging process. The rate of off-gassing depends on temperature, humidity, air circulation, and the age and condition of the material.

Heat accelerates off-gassing. This is established chemistry: higher temperatures increase the vapor pressure of volatile compounds, causing them to evaporate faster. A tape applied to a surface that reaches 130°F off-gasses at a materially higher rate than the same tape at 70°F. In HVAC applications, tapes applied to supply ducts, return plenums, and mechanical equipment are routinely exposed to elevated temperatures during normal operation.

Installation quality matters. A tape applied to a clean, dry surface under controlled conditions behaves differently from a tape applied to a dusty, damp, or irregular surface in the field. Poor adhesion can cause the tape to delaminate, exposing more adhesive surface area to the airstream and increasing off-gassing. Wrinkled or overlapping tape traps adhesive between layers, creating pockets where volatile compounds concentrate before releasing.

FSK tape — the specific material at issue in Unit 806. FSK stands for foil-scrim-kraft: a laminated tape consisting of an aluminum foil face, a fiberglass scrim reinforcement layer, and a kraft paper backing, bonded together and coated with a pressure-sensitive adhesive. It is used in HVAC systems as a vapor barrier and duct sealant.

The adhesive layer in FSK tape is the primary source of off-gassing. It typically contains one or more of the following:

• Toluene — a solvent used in adhesive formulations; a known central nervous system depressant at elevated concentrations
• Xylene — a solvent and carrier in adhesive systems; causes respiratory and neurological symptoms
• Styrene — used in some adhesive polymers; classified as a possible human carcinogen (IARC Group 2B)
• Formaldehyde — released from some adhesive resins and kraft paper treatments; a known human carcinogen (IARC Group 1) and potent respiratory irritant

When FSK tape is applied to a warm surface — such as an HVAC duct carrying conditioned or heated air — and the adhesive layer is exposed to sustained elevated temperatures, the rate of off-gassing increases. In a poorly ventilated or negatively pressurized space, the emitted compounds accumulate rather than dispersing. The result is an indoor air quality problem that may not be present at all times but recurs whenever the temperature, airflow, and ventilation conditions align.

This mechanism — FSK tape adhesive off-gassing under heat into a negatively pressurized unit — is directly relevant to Unit 806. The tape was installed by building maintenance. The elevated surface temperatures were documented by FLIR thermal imaging. The negative pressure was created by the single-hose portable AC the building provided as a substitute for the failed HVAC system.

Why a Single Test Proves Nothing

Air sampling captures a snapshot. It measures the concentration of specific compounds at one location, at one moment, under one set of conditions. It does not capture what was in the air an hour earlier, what will be in the air an hour later, or what is in the air in a different part of the same space.

Episodic exposures are the norm, not the exception. VOC off-gassing from building materials is not constant. It varies with temperature, humidity, airflow, mechanical system operation, and occupant activity. A tape that emits measurable toluene at 2:00 PM when the duct surface is at 140°F may emit nothing detectable at 9:00 AM when the system has been off overnight. A unit that draws contaminated air through wall cavities when the portable AC is running may have clean air when the AC is off and the windows are open.

A clean sample does not prove the space is always clean. This is a fundamental limitation of snapshot sampling, and it is well understood in the industrial hygiene profession. The absence of a detectable compound at the moment of sampling means only that the compound was not present at a detectable level at that moment. It does not mean:

• The compound was never present
• The compound will not be present in the future
• The compound was not present at harmful levels under different conditions
• The space is safe for continuous occupancy

Timing, location, and conditions determine what a test finds. A competent investigator designs a sampling strategy that accounts for variability: multiple locations, multiple times, under the conditions most likely to produce exposure (worst-case scenario sampling). A single sample taken under favorable conditions — windows open, HVAC off, low temperature — will predictably show low or undetectable levels. That does not mean the problem does not exist. It means the test was not designed to find it.

The statement “no indication of hazardous fumes” at one moment does not mean there was never hazardous exposure. Without knowing when the sample was taken, under what conditions, at what location in the unit, using what instrument, with what detection limits, and analyzed by what method, the statement is scientifically meaningless. It is a conclusion that cannot be evaluated because its methodology was never disclosed.

The Standard

The complete 42-chapter handbook is available as a PDF: Investigating VOCs in High-Rise Residential Buildings.

A plain-English reference guide is also available: VOC Layman’s Reference Guide.