Monitoring Indoor Air
Quality and Pollutants
in the Workplace

Air quality monitoring can determine a number of issues within a building, including thermal conditions, air exchange, airborne hazards, sources of microbiological contamination and overall hygiene.

In this blog, Susan Cassells, business development manager for SOCOTEC’s Environment & Safety division, explores how organisations can improve indoor air quality on their premises to safeguard employees against a host of occupational health concerns.

What is indoor air quality?

Indoor air quality can be defined as the quality of the air within and around buildings. Carbon monoxide, radon, indoor particulate matter and Volatile Organic Compounds (VOC) have been identified as the four major indoor air pollutants, with poor indoor air quality associated with occupational health risks such as sick building syndrome and heart/lung-related illnesses.

According to research by the EPA, the levels of indoor air pollutants are often two to five times higher than those outdoors. Given that we spend an average of 90% of our days indoors, it is important that duty holders regularly monitor air quality within their buildings in order to protect against the damaging impacts of indoor pollution.  

How can I improve indoor air quality?

Ensuring good air quality is important when premises have been subject to a change in use or activities, particularly when they have been left unoccupied for a period of time. A number of technical checks can provide an indication as to the quality of indoor air, highlighting possible problem areas where ventilation rates are poor. SOCOTEC undertakes surveys across a wide range of premises, including manufacturing, office, engineering, logistics and educational buildings, determining specific conditions in the working environment and providing tailored solutions to ensure safe and suitable working conditions.

Currently, good ventilation rates are imperative to reducing the quantity of indoor air pollutants, as well as minimising the risk of transmission from COVID-19. Government advice recognises the increased risk of viral transmission from mixing indoors and therefore recommends opening windows to ensure satisfactory rates of ventilation. In premises where ventilation is provided via air conditioning, it is essential that sufficient fresh air is added to any recirculated air and that ventilation rates are adequate to minimise the risk of transmission. As well as sufficient ventilation, keeping on top of your cleaning regime is important to help tackle the harmful effects of indoor pollution. It can also be worth investing in an air purifier or a dehumidifier to tackle particularly damp areas.

How do I check indoor air quality within my premises?

To monitor levels of indoor air pollutants, samples can be taken onto agar plates and examined for the presence of Total Bacterial Viable colonies, yeasts and moulds. This can identify the presence of dampness or mould within a property, with further checks carried out to determine the extent of microbiological contamination on surfaces (including COVID-19) and assess the cleanliness and overall hygiene measures in place within a building.

Air exchange is essential to prevent the build-up of carbon dioxide (CO₂) gas, which is present in the atmosphere at levels between 400 and 500ppm. When a building is occupied, exhaled CO₂ can increase in the atmosphere if the ventilation rates are poor. Increased CO₂ can lead to lethargy and headaches, as well as complaints of stuffiness, with levels above 1000ppm an indicator that ventilation rates are inadequate.

Are VOCs dangerous?

Volatile Organic Compounds (VOCs) are harmful, carcinogenic pollutants which are present in many everyday chemicals, including air fresheners, deodorants, cleaners, paints and varnishes. Additionally, building fabrics such as carpets and furnishings can also release VOCs into the workplace. They can be defined as a group of compounds with high vapour pressure and low water solubility. The overall amount of VOCs in a given space is known as the Total Volatile Organic Compounds (TVOCs) – this is a term that does not have a standardised definition given that the various groupings of TVOCs are subject to interpretation.

The health effects associated with VOCs depend largely on the concentration and level of pollutants in an indoor environment. Inhalation of high concentrations of VOC can lead to narcotic effects, including headache, lethargy, changes in perception and nausea. Exposure to levels which are likely to result in serious health effects is unlikely to occur except in industrial processes, whereby large quantities of solvent are being used with inadequate control. This can lead to irritation of the lungs, as well as damage to the kidneys, lungs and nervous system.

Lower levels of VOC are unlikely to result in any significant health effects, although they do provide a good indication of poor ventilation rates and allow for a gradual build-up of VOCs in the atmosphere. This can be confirmed by determining ventilation rates from supply and extract air systems, allowing for an estimate of total ventilation rates within any occupied area to be determined.

What causes high VOC levels?

The Chartered Institute of Building Service Engineers (CIBSE) recommends a range of temperature and humidity levels to create comfortable conditions. However, if not correctly monitored and controlled, both temperature and humidity can lead to high TVOC levels, with high levels of humidity leading to mould growth and sensations of dampness. They can also reduce the body’s ability to control its temperature through the evaporation of sweat, invoking the feeling of uncomfortably high temperatures. At the same time, low humidity can lead to dryness of the eyes and throat, as well as the complaint of static discharges if the humidity levels are particularly low.

Levels of fine particulates (dust) are also known to cause high TVOC levels. Present in varying concentrations within most workplaces, they can be generated by a number of activities or processes on site. It is essential for duty holders to minimise the presence of particulates in the workplace, as not only can they cause a visible impact on surfaces, they can also lead to respiratory issues if levels are elevated or employees are subject to continued exposure.

How can SOCOTEC support my organisation with indoor air quality?

SOCOTEC can carry out air quality monitoring and assessments within your organisation’s premises to determine the presence/levels of indoor pollution. Findings from assessments are then presented in a written technical report and referenced against current guidance and industry knowledge, along with remedial actions to ensure that appropriate measures can be implemented.