Technical Guide: Workplaces and Air Quality

Do you know what health effects the air quality of your workplace has? Since currently, due to changes in lifestyle, we spend about 80% of our time in enclosed environments (such as our workplace), it is essential to ensure indoor spaces with quality indoor air. Below, we explain the main guidelines that the National Institute of Occupational Hygiene (INHT) recommends through its Technical Guide for the assessment and prevention of risks related to the use of workplaces.

What does the Technical Guide state about air quality?

In its Appendix 5, Indoor Air Quality. Ventilation of Workplaces, the technical guide outlines the relationship between the airtightness of buildings due to energy efficiency requirements and the quality of indoor air. Likewise, the use of non-natural materials (causing the emission of chemical products) and insufficient air renewal contribute to unhealthy work environments.

Air with the presence of contaminating particles favors the appearance of ailments and health disorders in individuals. The symptoms are varied: irritation and dryness of mucous membranes, headaches, drowsiness, etc. In the case of microbiological agents, allergy cases (such as asthma) or infections (legionellosis) may occur.

Factors Influencing Indoor Air Quality

We can establish three factors that directly affect the quality of indoor air in workplaces:

Outdoor Air Quality

Since the air that is blown into the interiors comes from outdoors, the quality of this air is important. The level of ambient pollution should be taken into account to incorporate air filtration and purification elements according to the building's environment. In any case, efforts will be made to place air intakes in areas where the air is cleaner, away from pollution sources. Existing air currents should also be considered.

Indoor Pollutants

The existence of sources of contamination (chemical and biological agents) within indoor spaces affects the quality of indoor air. This will be affected by the emission of volatile organic compounds (VOCs) released by construction materials, cleaning products, and biological effluents produced by the occupants themselves.

To avoid increasing indoor pollution, a sufficient ventilation flow must be ensured. For this, correct sizing of the ventilation system is essential.

Ventilation System

The ventilation system used to renew the air in the spaces directly influences the air quality. Thus, the use of traditional ventilation methods (natural ventilation) or hybrid ventilation has proven inefficient and insufficient in ensuring comfort.

The former does not guarantee the absence of mold and fungi in spaces with high relative humidity, as it is often impossible to ventilate the spaces for the necessary time. The latter, being an unbalanced ventilation system, does not ensure that the volume of extracted air is equal to that of the supplied air (with the negative consequences for well-being that this entails). Likewise, it does not guarantee that the hygrothermal conditions are maintained within the recommended parameters (between 50% and 60%), since the supplied air, albeit filtered, is introduced with the hygrothermal characteristics of the outdoor air.

A controlled mechanical ventilation system is the best air renewal system. In addition to guaranteeing the extraction of contaminated air from the interior and supplying clean air from outside, it allows for control over the flow rate and relative humidity levels.

It is essential to ensure proper maintenance and cleaning of all system components. Likewise, filters should be replaced according to regulations, and a ventilation system should be installed that allows for the necessary access points to carry out periodic maintenance actions.