Focus on construction: Built-in antimicrobial protection for a greener construction sector

11 December 2023

Construction materials are particularly susceptible to the growth of fungi – such as moulds and mildews – and are often inaccessible for routine cleaning or inspection. Fungi reproduce through air-dispersed spores that are invisible to the naked eye, which can then settle and propagate on almost any surface. Uncontrolled proliferation of these organisms may eventually cause visible and structural damage to materials, including staining, discolouration, odours and reduced physical strength. This degradation can potentially create an unpleasant environment for building occupants and elicit considerable safety concerns, shortening the usable lifetimes of products. Frequently maintaining or replacing building components can also be very inconvenient and expensive for property owners, and may incur additional expenses associated with temporary relocation or lost business.

A prime example of a building material susceptible to fungal growth is PVC, a popular and highly versatile polymer with exceptional physical properties and fire resistance and an excellent cost-to-performance ratio. Unfortunately, PVC goods – such as roofing membranes – are at particular risk of fungal attack, as they contain plasticisers that provide micro-organisms with a nutrient-rich food source. In addition, membranes are often used for flat roofs, which can hold water for longer, contributing to the creation of an ideal environment for microbial growth. 

Addressing the gap in the market

The structural risks associated with mould and mildew, coupled with the cost and inconvenience of replacing damaged building materials, have sparked interest in preventative antimicrobial technologies that could extend the usable lifetimes of these products. These chemistries can be built into a variety of substrates during the manufacturing process to provide around-the-clock product protection against the growth of damaging microbes, including moulds and mildews. This helps to prevent the colour changes, odours and reduced performance caused by uncontrolled fungal proliferation, extending the usable lifetimes of roofing materials for greater safety and sustainability. 

Historically, arsenic-based 10,100-oxybisphenoxyarsine (OBPA) was a common antifungal agent used to protect a range of products against fungal growth. However, the safety of this compound was recently called into question, as it was discovered to be highly toxic to a range of organisms. Studies have also shown that OBPA readily leaches into water sources, causing harm to aquatic life. To make matters worse, this arsenic-based compound is also a recognised carcinogen, posing a risk to human and animal health. Consequently, OBPA was totally banned in the EU in 2016, and was also added to the REACH restricted substances list, meaning that goods imported into the EU cannot contain this compound. This ban caused roofing manufacturers to seek safer alternative technologies with improved toxicology profiles and broader consumer acceptance. Furthermore, international building specifications are becoming ever more stringent, and now frequently call for improved levels of sustainability, motivating architects and contractors to source materials with enhanced durability.


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Innovative solutions for peace of mind

Microban International has responded to the pressing, industry-wide need for alternative antimicrobial protection by developing MicroGuard, a range of metal-free, globally compliant antifungal formulations for PVC, PU and EVA foam applications. MicroGuard is designed to provide superior product protection, enhancing the cleanliness and longevity of a broad selection of polymer materials used across the construction sector. The technology boasts high antimicrobial efficacy and UV stability, as well as improved toxicity compared to existing arsenic-containing antimicrobial additives, such as OBPA. MicroGuard operates by preventing fungal microtubule structures from forming – terminating cell division – and by disrupting enzyme activity, blocking energy production pathways and leading to cell death.

MicroGuard is available in both masterbatch pellet and liquid formulations that can be easily incorporated into a spectrum of building materials at the point of manufacture, ensuring uniform distribution. It does not affect the appearance or function of the final goods, and its active agent becomes an intrinsic component of the item, actively inhibiting fungal growth 24/7 for the product’s expected lifetime. Microban® antimicrobial technologies are all registered with the US Environmental Protection Agency and compliant with the UK and EU Biocidal Products Regulation standards. They have a long history of safe and ffective use in the construction industry, and do not hinder compliance with complex building specifications, providing reassurance to contractors.

Contributing to a circular economy

Inhibiting microbial growth minimises the need for excessive cleaning of building components and surfaces – which demands large amounts of water, energy and harsh chemicals – and prevents product degradation to reduce the volume of plastic waste entering landfill. In addition, MicroGuard does not wear off or leach out into the environment over time, further minimising ecological concerns. MicroGuard is at the forefront of Microban’s efforts to mitigate the adverse environmental impacts associated with the overconsumption of polymers across multiple industries. In recognition of this, the product has recently been awarded the title of ‘Sustainability Product of the Year’ at the Business Intelligence Group’s Sustainability Awards 2023, as well as recognition at the 2023 FacilitiesNet Vision Awards. Pioneering metal-free antimicrobial chemistries such as MicroGuard enables the manufacture of construction materials with excellent antifungal product protection, without stimulating the environmental concerns associated with toxic alternatives. This novel solution is allowing architects, contractors and property owners to select building components with enhanced longevity and structural integrity, while simultaneously supporting the industry’s green transition.

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