Interior Air Quality and Reduction of Volatile Organic Compounds (VOCs)

CONTEXT

The term “interior air quality” is applied to non-industrial interior environments: facilities, office buildings, restaurants and homes. As it does not cause immediate adverse health effects, the importance and impact of the quality of interior air tend to be somewhat disregarded. Poor interior air quality affects both the physical and mental health of the occupants of the building, generating higher levels of stress, reducing employee performance and producing malaise in its occupants.

Volatile Organic Compounds (VOCs) are a group of chemical substances that are easily converted into vapours or gases, mainly petrochemical industry derivatives. Although their presence in interior air is imperceptible to human beings, there is a wide variety of consumer products and construction materials that emit such substances. paint, varnish, rugs, plastic, particle boards, etc. VOCs are also present in cleaning products, pesticides and cigarette smoke. The problem is that these types of substances can accumulate in interior spaces if the ventilation system is not adequate. Climate change affects the quality of exterior air and, in turn, the types of constructions that are developed, tending towards their hermeticity. This lack of ventilation affects the quality of the interior quality of homes and facilities, affecting people’s health.

The most abundant VOCs in the air are formaldehyde, isocyanates, benzene, me-thane, toluene, propane and ethylene. Some VOCs are classified as carcinogenic substances, such as benzene.

Exposure to VOCs mainly occurs through respiration, but it can also occur through the skin. Exposure to VOCs (prolonged or isolated) may cause respiratory problems, eye and throat irritations, dizziness, irritability, concentration problems, etc. In the long term it may cause renal, endocrine or central nervous system damage. Moreover, as they are fat-soluble they are bio-accumulated in the fats of living beings, so they are very difficult to naturally remove from the body.

The population groups most affected by the presence of contaminants in the interior air are babies and small children, pregnant and lactating women, and the elderly.

OBJECTIVE

Minimise the presence of VOCs in interior spaces with the aim of preventing ad-verse health effects.
Foster awareness about non-toxic constructed environments and about the design of healthy buildings.

PROPOSALS AND RECOMMENDATIONS

Control the quality of interior air, acting on three basic factors:
- The contamination source, taking into account construction materials, cleaning products and office activities, like the use of photocopiers.
- The means of dispersal of the contaminants, increasing ventilation, choosing the most suitable cleaning method (HEPA filter vacuums, for example) and maintaining the ventilation system.
- The receiver, limiting and avoiding exposure, for example, when using pesticides, painting or carrying out renovation or repair work.
Avoid the use of construction and decoration materials that contain formaldehyde and other VOCs. The VOC emissions of each construction material can be consulted on their technical data sheets.
Choose low-VOC emission materials, especially in the following categories: paint, varnish, sealants, and wall and ceiling coatings. Accordingly, it is advisable to use databases of healthy and non-toxic materials, such as those described in the “Reference Experiences” section.
Use water-based products wherever possible. Avoid solvent-based products.
Respect the periods stipulated for the dispersal and reduction of the levels of contaminants from construction materials. Intensely ventilate the building in the final phases of construction before occupation, using mechanical, natural or mixed ventilation. Guarantee that the pipes and filters of the ventilation system are correctly cleaned before the building is occupied.
Avoid the use of construction materials and cleaning products that contain formaldehyde. Establish low-emission maintenance and cleaning product purchasing policies. This type of characteristic can be consulted on the technical data sheets and safety sheets of the various products.
Use non-chemical methods for pest control wherever possible and increase ventilation when pesticides are to be used in the interior. If the use of chemicals is necessary, establish protocols for their use and always ventilate thoroughly afterwards.
Improve knowledge about exposure to contaminants in interior environments and their impact on health. To do so, provide information and recommendations for the occupants of these buildings about factors that can affect the quality of interior air.

REFERENCE EXPERIENCES

International Well Building Institute. “Well Building Standard - Air/VOC Reduction”.
International Well Building Institute. “Well Building Standard - Air/Air Quality Standards”.
Ministerio de Energía y Medio Ambiente del Gobierno Francés. Sistema obligatorio de etiquetado de materiales de construcción según el nivel de emisiones de COV.
Agència Francesa per a l'Alimentació, Ambient i Salut Ocupacional (ANSES). “Indoor air quality".
Friendly Materials, “Guía de materiales de construcción saludables”.
Green Building Council España, “Plataforma de materiales”.