Understanding Total Volatile Organic Compounds (TVOCs)
The air inside buildings can contain various substances, including Volatile Organic Compounds, or VOCs. These carbon-containing chemicals readily vaporize or “off-gas” into the air at typical room temperatures. VOCs are widespread, found in many everyday indoor items.
When discussing indoor air quality, “Total” Volatile Organic Compounds, or TVOCs, refers to the combined concentration of a broad spectrum of individual VOCs present in an air sample. It serves as a general indicator of the overall chemical load in the air rather than measuring a single specific chemical. Thousands of different VOCs exist, making individual measurement complex and impractical for general assessment, which is why the TVOC metric is frequently used in indoor air quality monitoring as it offers a quick overview of the chemical presence.
Common Sources of TVOCs in Indoor Environments
Many items within homes and other indoor spaces release TVOCs into the air through a process called off-gassing. Building materials and furnishings are significant contributors, particularly when new. Examples include paints, varnishes, adhesives, sealants, and various types of flooring like carpeting and vinyl, along with engineered wood products such as particleboard and plywood.
Household products are another common source of these compounds. This category encompasses a wide range of items, including cleaning supplies, disinfectants, and air fresheners, as well as pesticides, solvents, and polishes. Even laundry detergents can contribute to the TVOC levels in indoor air.
Personal care products also release VOCs during their use. Cosmetics, perfumes, and hairsprays are examples, as are nail polish and its removers.
Certain activities and hobbies can increase indoor TVOC concentrations. Cooking fumes are a common source, and the burning of tobacco or other substances significantly releases VOCs. Dry-cleaned clothing can off-gas chemicals, and craft supplies like glues and markers, along with burning candles or incense, also contribute to the overall TVOC load.
Health and Air Quality Impacts of TVOCs
Elevated levels of TVOCs can diminish indoor air quality, often leading to unpleasant odors and a sensation of stuffiness within a space. This general chemical presence is frequently the first noticeable sign of higher TVOC concentrations.
The specific health effects from TVOC exposure depend on several factors, including the particular types of VOCs involved, their concentration in the air, the duration of exposure, and an individual’s personal sensitivity. Some people may experience symptoms at lower concentrations than others.
Short-term or acute effects are commonly observed when TVOC levels are elevated. These immediate symptoms can include irritation of the eyes, nose, and throat, often accompanied by headaches. Dizziness, nausea, fatigue, and allergic skin reactions are also reported by individuals exposed to higher concentrations of TVOCs. These symptoms typically subside once the exposure is reduced.
Prolonged exposure to higher TVOC levels can lead to more persistent health issues. Respiratory problems, such as the exacerbation of asthma symptoms, are a concern. While TVOC is an aggregate measure, certain individual VOCs within that total are linked to more serious outcomes, including potential damage to the liver, kidneys, or central nervous system. Some individual VOCs are recognized as known or suspected carcinogens, underscoring the importance of managing overall chemical exposure.
Strategies for Reducing TVOC Levels
Controlling sources is often the most effective way to reduce TVOC levels in indoor environments. When undertaking renovations or furnishing new spaces, selecting low-VOC or no-VOC products for paints, varnishes, and adhesives can significantly limit chemical emissions. Opting for solid wood furniture over pressed wood products, or allowing new items to off-gas in a well-ventilated area before bringing them indoors, also helps to minimize these emissions.
Careful selection of household products contributes to lower TVOC concentrations. Choosing cleaning products, personal care items, and air fresheners with fewer chemical ingredients or those labeled as “fragrance-free” can reduce airborne VOCs. Storing chemical products such as paints, solvents, and cleaning agents in tightly sealed containers in well-ventilated areas, ideally outdoors or in a garage, prevents their off-gassing into living spaces.
Proper ventilation is another important strategy for managing indoor air quality. Regularly opening windows and doors increases the circulation of fresh air, especially when using products that off-gas. Utilizing exhaust fans in kitchens and bathrooms helps to remove pollutants directly at their source, preventing their dispersion throughout the home.
While less effective than source control and ventilation, certain air purifiers can supplement reduction efforts. Air purifiers equipped with activated carbon filters can help absorb some VOCs from the air. However, it is important to avoid ozone-generating air purifiers, as ozone can react with VOCs to form other potentially harmful compounds. Maintaining moderate temperature and humidity levels indoors can also help reduce the rate at which some materials off-gas.