Odors That Warn: Identifying Pollutants By Smell

Odour is increasingly being recognised as an atmospheric pollutant, with several countries attempting to regulate emissions. Odour can be an important warning signal, as people are often more sensitive to smells than instruments. For example, formaldehyde, which is emitted by furniture and wood panelling, has a sharp and irritating smell. Other indoor pollutants with strong smells include aromatics, aldehydes and terpenes.

Volatile organic compounds (VOCs)

Some common sources of VOCs include furniture and wood panelling, which often emit formaldehyde, a sharp and irritating odour. New carpets can also release VOCs, specifically 4-phenylcyclohexene, which is often described as the "new carpet smell". Other chemicals that are frequently present indoors and can have strong odours include aromatics such as toluene, styrene, and xylene, aldehydes such as formaldehyde and acetaldehyde, and terpenes such as α-pinene and limonene.

The characterisation of odours, both qualitative and quantitative, can be useful in identifying the sources of VOC pollution. This is because human sensitivity to odour is much greater than that of instrumental methods, and the ability to distinguish among different odours can help determine the possible source of an odour in complaint investigations. For example, in an office with complaints of an uncomfortable smell, carbonyl chemicals and VOCs were investigated, and the odour was evaluated by non-smoker odor assessors who recorded the odor characters that appeared in the offices.

Overall, VOCs are a significant concern when it comes to air quality and human health, and the ability to recognise them by odour can be an important tool in identifying and addressing sources of pollution.

Formaldehyde

Odour can be a warning signal for pollutants. Humans are more sensitive to odours than instruments, and the character of an odour can help determine its source. Some countries are trying to classify odour as an atmospheric pollutant.

To reduce exposure to formaldehyde, it is recommended to increase ventilation and air exchange rates in indoor spaces. Using products with low or no formaldehyde content can also help reduce exposure. In addition, some air purifiers can effectively remove formaldehyde from the air.

New carpets

The smell of new carpets is often described as a sharp and irritating odor, similar to that of formaldehyde, which is emitted by furniture and wood paneling. While the odor of new carpets is usually mild and intermittent, it can be a cause for concern for some people, especially those with sensitivities to certain chemicals.

The presence of 4-phenylcyclohexene in new carpets is due to the manufacturing process and the materials used. This chemical is released as the carpet ages and off-gasses, which is a normal part of the carpet's life cycle. However, it's important to note that the off-gassing process can take several months or even years, depending on the carpet's quality and the environment in which it is installed.

To minimize the odor of new carpets, proper ventilation is crucial. Opening windows and doors, as well as using fans or air purifiers, can help dissipate the smell more quickly. Additionally, some people choose to air out their new carpets outdoors before installation, although this may not always be practical or possible.

If you are sensitive to odors or have concerns about the potential health effects of 4-phenylcyclohexene, it is advisable to consult with a healthcare professional. While the odor of new carpets is generally not considered harmful, everyone's tolerance and sensitivity to chemicals are different. Taking precautions, such as improving ventilation and choosing carpets with lower VOC emissions, can help create a healthier indoor environment.

Aromatics

Toluene is a colourless, water-insoluble liquid with a smell similar to paint thinners. It is a common solvent, used in contact cement, glues for shoes, and permanent markers. It is also used in the production of benzene and as a gasoline additive.

Styrene is a colourless oily liquid with a sweet smell. It is used in the production of polystyrene and several copolymers, as well as in paints and varnishes, and in making fibreglass.

Xylene is a colourless, flammable liquid with a sweet smell. It is used as a solvent in the printing, rubber, and leather industries, and as a cleaning agent. It is also used in the manufacture of dyes and pharmaceuticals.

Aldehydes

Formaldehyde, also known as methanal, is a colourless gas with a strong, pungent odour. It is used in a variety of industrial applications, including the production of resins, adhesives, and plastics. Formaldehyde can also be found in some household products, such as cleaning agents and personal care products. Exposure to formaldehyde can cause a range of health issues, including eye, nose, and throat irritation, as well as headaches and nausea.

Acetaldehyde, on the other hand, is a colourless liquid with a fruity or vinous odour. It is produced naturally in small amounts by the body and is also found in some foods and beverages, such as ripe fruits and alcoholic drinks. However, exposure to high levels of acetaldehyde can be harmful, causing respiratory irritation, eye and throat pain, and even damage to the central nervous system.

The presence of aldehydes in indoor environments can be a cause for concern, as they can contribute to poor air quality and potential health risks for occupants. It is important to be aware of the sources of aldehydes and to take steps to reduce exposure, such as proper ventilation and the use of low-emission products.

In summary, aldehydes are a group of chemicals that can be recognised by their distinct odour and are commonly found in indoor environments. While they may be present in small amounts in some natural products, high levels of exposure to aldehydes can be harmful and should be avoided. It is important to be vigilant about the potential sources of aldehydes and to take preventative measures to ensure good air quality and maintain health and safety.

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