Understanding hazard and risk in liquid roofing specification

Gavin White from leading liquid applied roofing specialist, Sika Liquid Plastics, discusses the importance of supply chain technical support in managing hazards and avoiding risk.


Even in the context of the building products market, where next-generation materials and a competitive environment are driving innovation, the liquid-applied roofing sector is particularly dynamic.

Product development in liquid-applied roofing membranes is being driven by the need for high levels of both performance and buildability, resulting in systems with enhanced service life, speed of installation and low-odour characteristics. With so many systems available and some bold product claims, however, it’s important that specifiers truly understand the capabilities offered by their product choices along with any hazards that may need to be managed during installation.

Low odour vs low hazard

Any construction project inherently involves a level of hazard. However, risk can be avoided if any hazards are known and managed. For example, in the liquid roofing sector, if skin contact with the product needs to be avoided, wearing appropriate PPE and following manufacturer guidelines on safe handling requirements can ensure that risk is avoided on site.

When it comes to inhalation hazards, however, the picture is more complex. Moreover, whereas skin contact hazards only have the potential to affect contractors actually using the product, inhalation hazards could also pose some level of risk to occupants of a building during a roof refurbishment project if they not correctly managed.

The dilemma for specifiers is that low-odour and low-inhalation hazards are not always the same thing. It’s perfectly possible for a product with a distinctive odour to present no inhalation hazard at all. Conversely, it’s equally possible for some low-odour liquid roofing systems on the market to present a surprisingly high level of inhalation hazard and risk if this is unknown and unmanaged.

Beyond compliance

To safeguard against the use of hazardous and environmentally harmful chemicals in the formulation of liquid roofing systems, all manufacturers must avoid using any chemicals banned by EU REACH regulations. The REACH banned list aims to ensure chemicals are not used if the level of hazard they involve is unmanageable.

Legally, all manufacturers must also clearly state all constituents with associated hazards for every product on the product safety datasheet.

These requirements are designed to help specifiers make safer and more informed choices. However, it’s important to understand that new chemical substances are constantly being developed and the REACH banned list is extended to include more banned constituents each year. As a result, liquid roofing systems can be REACH compliant but still include potentially hazardous constituents in their formulation.

When it comes to low-odour products, it’s particularly important to be confident that none of the constituents pose any inhalation hazards because the lack of any unpleasant odours could make contractors and building owners less vigilant.

Supply chain partnership

By working with a supply chain partner that is both proactive and candid in identifying hazards, the specifier can be confident of avoiding any design responsibility risk and any potential risk for contractors or building occupiers on site.

For example, as part of the global Sika network of companies, Sika Liquid Plastics adheres to an internal Sika banned substances list, which includes many substances not currently banned by EU REACH regulations. This not only means that we avoid using any constituents identified by Sika’s global compliance department in our product formulations; it also enables us to be a step ahead of any new REACH compliance requirements when developing new, high-performance roofing solutions.

Proof and performance

Specifiers should not only be able to rely on their roofing supply chain partners for clear and honest advice on both performance and hazards, but should also expect product claims to be backed by credible test data.

While terms like ‘low odour’ and ‘odourless’ are unregulated and subjective, inhalation risk is quantifiable using the HSE’s WELs (Workplace Exposure Limits). Regardless of whether a liquid roofing system has a noticeable odour or not, it should have been through a thorough testing process, including third-party lab tests and occupational exposure testing in an environment that simulates a real-world installation environment.

Indeed, when Sika Liquid Plastics tested the Decothane Ultra low-odour roofing system prior to launch, a box test was used to assess inhalation hazards against WELs of the constituent components. This involved trapping the freshly-applied coating and detector inside a box immediately after application. Even in this extremely confined space, Decothane Ultra, like all Sika Liquid Plastics’ systems, was found to be significantly below WELs levels.

Testing products to worst-case-scenario levels for inhalation hazards in this way ensures that contractors are protected from risk, even when working in confined areas of the roof. Similarly, it protects building occupiers from any inhalation risk during refurbishment projects.

Specifiers can also ensure that hazards are managed on site by working with a supply chain partner that offers a complete service and technical support package. For example, regular inspections by Sika’s Roofing Applications Team, mean that all Sika Liquid Plastics projects are monitored for installation practices that support high levels of both safety and performance.

Safety centre stage

The liquid roofing sector continues to offer specifiers a variety of options, enabling them to choose a best-fit system to meet the specific installation and performance criteria for their new-build or refurbishment project. Safety must be integral to those criteria and only by working closely with the supply chain can specifiers ensure that risk is avoided with an informed and proactive approach to understanding and managing hazards.

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