VOCs in Building
The term “VOC” covers hundreds of individual chemical compounds. Health Canada and WorkSafeBC use exposure guidelines based on specific compounds rather than total VOC levels, since a given chemical’s toxicity varies enormously. Some of the most commonly encountered VOCs in building assessments include: Cleaning agents, sanitizers, print media
Long-term or acute exposure to elevated VOC concentrations has been linked to a range of health effects — from eye, nose, and throat irritation at lower levels to central nervous system effects, liver and kidney damage, and in the case of benzene, carcinogenicity with chronic high exposure. In an occupational context, WorkSafeBC sets legally enforceable Occupational Exposure Limits (OELs) for specific compounds. For residential or general commercial buildings, Health Canada’s residential indoor air quality guidelines provide the relevant benchmarks.
Key distinction: Total VOC (TVOC) readings from low-cost consumer sensors are not a reliable basis for health decisions. Professional assessments are more accurate and can measure individual compounds against compound-specific exposure limits.
Common Sources of VOC Contamination in Buildings
Before sampling begins, a qualified assessor conducts a source investigation — because identifying the likely compounds guides the choice of sampling method and analytical target list. Common sources we encounter include:
- Building materials: Engineered wood products (plywood, MDF, OSB), spray foam insulation, carpet adhesives, and caulking compounds all off-gas formaldehyde and other aldehydes, particularly in the months following installation.
- Renovation activity: Paints, primers, solvents, epoxy coatings, and flooring adhesives introduce a sharp spike in VOC concentrations that can persist for weeks in poorly ventilated spaces.
- Industrial processes: Print shops, auto body facilities, dry cleaners, laboratories, and cannabis production facilities generate occupationally significant VOC levels as part of normal operations.
- Consumer products: Cleaning agents, air fresheners, personal care products, and photocopiers contribute to background VOC loading in office environments.
- HVAC deficiencies: Inadequate fresh air supply, recirculation of contaminated air, or HVAC systems drawing from contaminated interstitial spaces can concentrate VOCs well above outdoor levels.
How VOCs Are Measured: Sampling Methods
Direct-Reading Instruments
Photoionization detectors (PIDs) provide real-time, non-specific VOC readings useful for screening and source-finding during the walkthrough phase of an assessment. A PID reading will identify areas of elevated contamination for targeted sampling, but cannot identify individual compounds and should not be used as the sole basis for regulatory compliance decisions.
Interpreting the Results: What Are the Benchmarks?
There is no single universal threshold for “acceptable” VOC levels — the appropriate benchmark depends on the building type and regulatory context:
- WorkSafeBC OELs apply in workplaces and are expressed as 8-hour TWA concentrations and 15-minute STELs. These are the legally enforceable benchmarks for occupational exposure in BC.
- Health Canada Residential Indoor Air Quality Guidelines provide long-term (annual average) and short-term (24-hour) guidance values for residential buildings, including formaldehyde, benzene, naphthalene, and others.
- ASHRAE Standard 62.1 addresses ventilation requirements and acceptable IAQ in commercial buildings, with reference to VOC minimization through source control and dilution.
- LEED and WELL Building Standards include VOC emission limits for building materials and finishes, relevant to new construction or certification projects.
Where concentrations exceed guideline values, remedial options typically include increased ventilation and dilution, source elimination or encapsulation, modified work practices, or respiratory protection as an interim measure. ABM Environmental provides actionable, prioritized recommendations tailored to the specific compounds, concentrations, and building conditions identified in the assessment.
VOC assessments require careful planning, calibrated equipment, and the right analytical targets — a consumer air quality monitor simply cannot provide the resolution needed to make defensible decisions about occupant health or regulatory compliance. If your building has occupant health complaints, recent renovation activity, or industrial processes involving chemical use, a professional assessment is the right starting point.