Monitoring VOCs Indoors
Volatile Organic Compounds (VOCs)
The legal limits on emissions of and exposure to VOCs vary from place to place, and are set by authorities including the European Union and the United States Occupational Safety and Health Administration OSHA. In the UK, there are currently no indoor air quality guidelines for individual volatile organic compounds. In their absence, the recently revised Department for Education Guidance BB101: Ventilation, thermal comfort and indoor air quality (DfE, 2018) recommended the use of the WHO (2010) Indoor Air Quality (IAQ) guidelines.
Monitoring Indoor Air For VOCs
Some public locations present exceptional levels of specific VOCs
Total emissions of particulates and volatile organic compounds other than methane (NMVOCs) in the UK have decreased by more than 50% since 1990. This is good news, and largely thanks to a dramatic decrease in vehicle emissions, a trend seen in many other countries. Simultaneously, research has revealed in more detail the exposure of people to particulates and VOCs, and their effect on health. Definitive thresholds have been compiled for VOC concentrations indoors such as those provided by Public Health England.
– Indoor Air Quality Guidelines for selected Volatile Organic Compounds (VOCs) in the UK, Public Health England, London, UK, 2019.
”Formaldehyde is a major air contaminant indoors, especially in newly furbished rooms, typically outgassing from fibreboard and plastics for a few months after installation. Fairly inexpensive monitors engaging metal oxide semi conductivity-based sensors provide robust responsively.
L Spinelle, M.Gerboles. G.Kok, T.Sauerwald, ‘Review of low-cost sensors for the ambient air monitoring of benzene and other volatile organic compounds’, J.R.C. Technical Report, E.U., 2015
Clean Air Strategy 2019
To further address the health and safety and environmental issues surrounding air pollution, in January 2019 the UK government launched a Clean Air Strategy to outline how they will tackle all sources of air pollution, making the air healthier to breathe, protecting nature and boosting the economy.
The strategy sets out how the government will;
- protect the nation’s health
- protect the environment
- secure clean growth and innovation
- reduce emissions from transport, homes, farming and industry
- monitor the progress
VOC Monitoring Indoors
Given the range of VOC’s in air and their variable harmfulness, it might seem preferable to monitor the more ubiquitous and harmful of them individually. Despite the technological revolution of recent decades, analysis of individual VOCs continues to rely upon gas chromatographic separation of volatiles, followed by their detection. The cost and service burden of such VOC analysers remains high – much too high for wide deployment. But some specific VOC detectors and sensors are commercially available.
Benzene arises primarily from external sources but is also found in paints. Selective monitors are available which engage miniaturised GC-PID (gas chromatography-photoionisation detection).
– W. Haag ad F. Dean Continuous Benzene-Specific Monitoring Using the Titan
Download our FREE Guide
“Monitoring Indoor Air For VOCs”
The monitoring indoor air for VOCs guide which can be downloaded below provides the reader with an in-depth balance of knowledge regarding how clean air is largely defined by the absence of VOCs apart from methane, and particulates. The VOCs of concern are chemically diverse, vary in their toxicity, and arise from several sources, both from indoors and out of doors. None the less the concept of ‘total volatile organic compounds’ is well recognised, being stipulated for example, in building ventilation guidelines. A few technologies are capable of detecting VOCs non-selectively. Of these, PID is the best suited and most widely deployed.