VOCs stands for Volatile Organic Compounds, which describes airborne chemicals. VOCs are both naturally occurring and manmade.
Additionally, it is important to distinguish between VOCs and TVOC (Total Volatile Organic Compounds). While VOCs refer to individual chemical compounds, TVOC represents the combined concentration of all detected VOCs, typically displayed as a single value on consumer air quality monitors.
Units of Measurement: mg/m³ vs ppm
mg/m³ (milligrams per cubic meter): A mass-per-volume unit that measures the weight of VOCs in a given air volume.
ppm (parts per million): A volume mixing ratio that measures the number of VOC molecules per million air molecules.
Conversion Challenges: Converting between mg/m³ and ppm requires knowledge of the specific VOCs present, their molecular weights, and environmental conditions like temperature and pressure. Since TVOC aggregates many compounds, precise conversion is not straightforward without detailed chemical composition data.
Why are VOCs important to monitor?
Harmful VOCs can cause health effects in both the short and long term. Health effects vary from minor eye, nose and throat irritations to more serious ailments, depending on the level of exposure to a particular chemical. It is important also to note that VOC sensors also simply detect chemicals associated with human or animal presence. So although some VOCs are not always bad for your health, they are important to monitor if consistently high and to experiment with ventilation.
Where do VOCs come from?
They come from an array of everyday items including paints and varnishes, wax and cosmetics, cleaning and hobby products, and even cooking. When you have an enclosed space like a home or office, these emitted gases accumulate and can pollute our fresh air. VOCs are actually also produced by humans, and it is useful to monitor total VOC levels in rooms to see when it's a good time to ventilate or identify potential sources.
Interpreting and Comparing VOC Readings Across Devices
Differences Across Brands: VOC readings may differ between devices due to variations in sensor technologies, calibration methods, and data sampling techniques. These differences can affect absolute values.
Focus on Patterns: When comparing devices, prioritize patterns and relative changes (e.g., spikes during specific activities) rather than exact numerical matches. This approach provides more actionable insights into air quality trends.
Candles and fires
Anything that burns gives off fumes. Fireplaces and scented candles are especially harmful, so keep an eye on your levels while using them.
Humans
Humans and animals also produce VOCs. The sensor detects VOCs in peoples breath (and perfume and other smells)
Nighttime spikes in VOC levels are often observed in bedrooms due to human presence and reduced ventilation. Emissions from breath, skin, and other human-related sources accumulate in closed spaces, leading to higher TVOC readings.
Fragrances
Mothballs, room deodorizers and perfumes—anything with a fragrance, contain chemicals that should be avoided.
Cooking fumes
Cooking also creates gases that can be toxic. Always use a hood fan or open a window while cooking indoors. And keep the door closed when grilling outdoors.
New furniture
New furniture, carpet, drapes, mattresses all contain chemicals that slowly release into the air, often for years after you bring them home.
Conversion Challenges Between Units
Converting between mg/m³ and ppm is complex and requires detailed knowledge of the specific VOCs present, their molecular weights, and environmental conditions like temperature and pressure. This complexity arises because TVOC readings aggregate many compounds, making precise conversion difficult without detailed chemical composition data.
Cleaning products
While cleaning with soaps, detergents, furniture polish and glass cleaners be aware of terpenes and ethanol and ventilate accordingly.
Craft products
Glue, paints, fabrics, wax, dyes, many craft products contain VOCs. Be sure to ventilate while using them.
Children's toys
Some hard plastics contain formaldehyde, and new fabrics emit toxins into the air. Look for BPA-free plastics or avoid plastics altogether, and wash toys before using them.
Paints and varnishes
Lacquers, paint, industrial glues, paint thinner and harsh chemicals should not be kept in the home, even when they are locked tight they emit chemicals into the air.
Please see here for an example of how particular VOCs are classified:
