Improve Indoor Air Quality
Gases, Vapours and Odours: What You can't See can Hurt You

The types of gases or vapours most often found in indoor environments include combustion byproducts, such as carbon monoxide, nitrogen oxides, sulfur dioxide, soot particles and polycyclic aromatic hydrocarbons (PAHs); phthalates; pet, human and cooking odours; ETS; volatile organic compounds (VOCs); and microbial VOCs and mycotoxins. Many of these substances also produce odours, some of which are pleasant while others can be distracting and irritating.

Volatile Organic Compounds. Among the most prevalent of all indoor air constituents are volatile organic compounds (VOCs), with as many as 100 to 1,000 different VOCs in the air where human can easily inhale them. Some VOCs can cause eye, nose and throat irritation; cough; headache; general flu-like illnesses; skin irritation; and some can cause cancer. Others produce odors that may be objectionable. Complicating matters is the potential for interactions of VOCs with other chemical compounds to form a third compound that also may be a threat. As a result, even though the concentrations of individual VOCs may be well below odor thresholds or known toxic levels, their occurrence in complex mixtures may lead to perceived poor IAQ or irritation among those exposed.

Majority of everyday chemical exposure occurs through the air we breathe in our homes, offices, schools and other indoor environments. These airborne chemicals are commonly referred to as volatile organic compounds (VOC's).

What are VOCs?

Volatile organic compounds are chemicals used to manufacture and maintain building materials, interior furnishing, cleaning products and personal care products. ‘Volatile' means that these chemicals evaporate or can easily get into the air at room temperature. ‘Organic' means these chemicals are carbon based. The term ‘chemical emissions' refers to VOCs as they evaporate into the air from products.

Studies by Environmental Protection Agency and other researchers have found that VOCs are common in indoor environments and that their levels may be two to a thousand times higher than outdoors. There may be anywhere from 50 to hundreds of individual VOCs in the indoor air at any one time. Some may produce objectionable odours at very low levels, but many have no noticeable smell. Many VOCs are irritants and can cause headaches, eye, nose and throat irritation and dizziness. Long-term exposure to certain VOCs may lead to chronic diseases or cancer. At high concentrations, some VOCs are toxic.

Where are VOCs Found?

The majority of VOCs found in the indoor environments originate from building materials, indoor furnishings, cleaning supplies, consumer products and processes, such as printing, cooking, hobbies, cleaning, interior renovations and pesticide applications.

A growing number of scientists also are concerned that exposure to very small traces of VOCs and some industrial chemicals in homes, schools and other buildings may have profound impacts on human health, including disruptions to the endocrine system (hormones), gene activation and brain development. An especially striking finding is some chemicals may have health impacts at extremely low levels, which are not seen at higher levels. Minute levels of phthalates, for example, which are used to make toys, building materials, drug capsules, cosmetics and perfumes, have been linked to sperm damage in men and genital changes, asthma and allergies in children (Waldman 2005, Bornehag et al 2004).