
Packaging producers advancing recyclability and circularity are increasingly verifying that new solutions do not drive up air emissions. Signal Group, a UK-based manufacturer of gas analysers, reports growing demand from the packaging sector for continuous volatile organic compound, VOC, measurement. VOCs are emitted in a range of processes used to make plastics, resins, fibres, textiles, elastomers, solvents, pigments and adhesives. These pollutants are tightly regulated, so continuous monitoring is necessary to demonstrate compliance and to avoid sustainability trade-offs. As Signal MD James Clements notes, "The packaging industry is currently under enormous pressure." He cites ESG commitments, customer expectations and regulatory drivers including the UK’s Extended Producer Responsibility and the EU's Packaging and Packaging Waste Regulation. A McKinsey report underscores the trend, stating, "The global packaging sector continues to be attractive and is expected to grow faster than global GDP," with rising interest in piloting sustainable packaging to reduce material use, increase circularity and make greater use of recycled materials. Clements cautions that the path is not linear: "It’s not as simple as that. Yes, waste reduction is enormously important, but the development of new packaging products can be a bit like ‘whack-a-mole’ because sustainability objectives also include other important factors such as carbon footprint and environmental emissions." He adds that manufacturers want to ensure they do not inadvertently increase emissions of pollutants such as VOCs, which is driving the uptake of continuous analysers.
VOC sources in packaging production
VOCs can arise at multiple stages of polymer and packaging manufacture. During polymerisation, unreacted monomers and residual catalysts may be released as VOCs. Additives introduced to tailor polymer properties can also be volatile and contribute to emissions. Thermal processing at elevated temperatures can degrade polymers into smaller, volatile compounds. In downstream converting, application of plastic membranes such as PET, HDPE, LDPE or PP to paper or board for food packaging is a typical source of VOCs that require abatement.
Regenerative thermal oxidisers, RTOs, are commonly deployed to oxidise VOCs in exhaust gases to carbon dioxide and water vapour. Effective abatement requires proper control and verification with gas analysis. In such systems, a flame ionisation detector, FID, from Signal can sample both inlet and outlet streams to assess destruction efficiency and demonstrate regulatory performance. This can be implemented with two FIDs or with one FID combined with a switched sampling system.
Monitoring technology and certification
The reference method for measuring VOC emissions is the flame ionisation detector. The FID technique selectively detects carbon hydrogen bonds, providing high sensitivity to VOCs. Signal manufactures fixed analysers for permanent installation and portable analysers for use at multiple sites where discontinuous monitoring is permissible. Portable instruments are typically applied at lower emitting facilities where periodic verification is sufficient.
Regulatory monitoring in many countries requires compliance with specific performance standards. Signal’s latest FID, the Solar Cemnex, recently passed a rigorous test programme at TÜV in Germany. As a result, the monitor has MCERTS approval verifying conformity with performance and uncertainty requirements specified in the UK’s Environment Agency Guidance: MCERTS for stack emissions monitoring equipment at industrial installations - Continuous emissions monitoring systems, CEMS, Updated 28 August 2024, EN 15267-1:2023, EN 15267-2:2023, EN 15267-3:2007 and QAL 1 as defined in EN 14181: 2014.
Balancing sustainability metrics
Sustainability claims may relate to lower carbon footprint, reduced environmentally harmful emissions, lower energy or water consumption, or waste reduction. However, improving one metric should not undermine another. Continuous or periodic VOC monitoring helps packaging manufacturers verify that innovations in recyclability or recycled content do not increase pollutant emissions. As Clements highlights, the sector is working to avoid a "whack-a-mole" effect by adopting robust measurement to support design, process control and regulatory compliance.