Understanding Volatile Organic Compounds (VOCs) and Indoor Air Quality

Understanding Volatile Organic Compounds (VOCs) and Indoor Air Quality

By Ruth MacEachern

Product Manager

Our previous article focussed on one particular element contributing to poor indoor air quality and an unhealthy living environment; namely, mould formation. We will now turn our attention to an often cited but arguably less familiar component of indoor air pollution – Volatile Organic Compounds, or VOCs. We will begin by discussing what volatile organic compounds are, before asking how they contribute to poor indoor air quality. Finally, we will outline a number of ways in which to control and minimise their presence in residential environments.

What are VOCS and how do they contribute to poor indoor air quality?

Volatile organic compounds are a group of chemicals that readily evaporate into the air. They are emitted from certain types of liquids or solids, in the form of gases and include both synthetic chemicals (such as formaldehyde) and natural elements (such as fungi). They are found in many common household products and building materials and are present in more or less all indoor air. Many VOCs are completely odourless and therefore, if left unchecked, can go undetected and cause a variety of health complaints. The Healthy House; an e-commerce business promoting health, wellbeing and the protection of the environment within domestic dwellings, lists potential short-term symptoms of VOC inhalation as follows:

• Headaches
• Dizziness
• Nausea
• Irritated airways and mucous membranes

Some VOCs have more serious long-term effects and can even be carcinogenic or cause damage to the kidneys and central nervous system. This is particularly alarming on account of the fact that numerous studies have VOCs quantities present in the average home to significantly exceed safe levels. A report drawn up by Airtopia; a social enterprise providing air quality testing and advice, found that “45% of homes had levels of Volatile Organic Compounds (VOCs) that exceeded healthy levels, with 17% reporting high-to-serious levels of VOCs” Among the sample group of homeowners surveyed, “28% of homeowners with high VOC readings reported multiple respiratory difficulties. The report identified that these high levels of indoor air pollution were mainly caused by the occupants’ day-to-day behaviour.

Sources of VOCs include paints, varnishes, alcohol products such as cleaning solutions, hand sanitisers, air fresheners, personal care products including deodorants, perfumes, hair dye, nail varnish, and scented candles”. Furthermore, the survey conducted found that in spite of high levels of concern regarding indoor air quality, levels of awareness as to the sources of indoor air pollution were low.

Volatile Organic Compounds and building regulations

While Approved Document F; the section of building regulations in England and Wales that addresses ventilation and air flow, stipulates a number of measures to improve indoor air quality and consequently reduce VOC levels, a document published by Public Health England goes one step further, identifying specific VOCs and offering guidelines and advice on how to reduce and eliminate the harmful chemicals from homes. Indoor Air Quality Guidelines for selected Volatile Organic Compounds (VOCs) provides a comprehensive list of VOCs commonly found in domestic dwellings, specifying why they were included, outlining potential health risks, and stipulating the limit values permitted in case of both short and long-term exposure.

Methods by which to reduce and eliminate VOCs

There are a wide range of ways in which you as a house builder can reduce or eliminate the presence of VOCs in your new buildings. These include:

• Consider using low-VOC paints and materials. Certain paints and some materials, such as MDF, have been shown to emit higher levels of VOCs than others. Solid wood with low emitting finishes will contain fewer VOCs than composite materials.
• Install adequate ventilation. Mechanical ventilation systems replace contaminated indoor air with fresh, filtered air drawn in from outside the property. Many ventilation systems also incorporate the ability to control temperature and humidity levels. It has been demonstrated that “chemicals off-gas more in high temperatures and humidity”. A MVHR or MEV system will replace contaminated air with fresh filtered air from outside the property, thus reducing the concentration of VOCs from the building materials you use, and also from products such as air fresheners and cleaning products used by your future customers.
• Ensure that appropriate filters are installed in vents and ventilation systems. Evidence shows that while HEPA filters do meet a specific standard of air-pollution removal and filter out certain particulate matter, they are not sufficient as a means by which to eliminate VOCs. In order to be classified as “HEPA,” which stands for High-Efficiency Particulate Air, a filter must remove at least 99.97% of all particles that are 0.3 microns and larger. This suffices to eliminate a range of pollutants such as pollen and dust particles, however, as VOCs are gas molecules, they are much smaller. Instead, active carbon (or activated charcoal) filters are required, whereby a process known as adsorption causes the VOCs to chemically bond with the carbon in the filter.

There are a number of further daily practices that can be recommended to home buyers to ensure that VOC levels remain within recommended healthy limits.

• Install an air purifier
• Keep plants that have been shown to absorb VOCs and improve indoor air quality. An article on the benefits of house plants is available here.
• Open windows to allow fresh air in and encourage air flow between rooms. An article outlining means by which to ventilate rooms without windows is available here.
• Avoid storing paints, caulks and solvents inside the home – you can avoid storing them altogether by purchasing only what is required.
• Look for cleaning and personal hygiene products that are natural, organic and unscented.

While all of these measures can help make a difference, an article in The Times discussing measures to indoor air quality in the wake of the coronavirus pandemic nicely summed up the most effective approach in the article’s title: “Ventilate, Ventilate, Ventilate!”. Good ventilation can improve indoor air quality by eliminating VOCs, preventing the formation of mould, and reducing the quantity of allergens in the air. The role of ventilation in reducing one of the most prevalent of these allergens, pollen, can be found in our article on how ventilation can help stop hay fever. For further advice on VOCs, air pollutants and appropriate ventilation systems, check out our catalogue of blog articles or contact our expert team.