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Polyurethane & Diisocyanates REACH 2023: Your Essential Guide to Compliance and Safety

Polyurethane & Diisocyanates REACH 2023: Your Essential Guide to Compliance and Safety


Polyurethanes, are versatile polymers integral to various industries and have faced a recent change in regulations. The REACH Restriction, effective from August 24, 2023, brings forth new guidelines and training requirements for professionals and industrial users. In this blog, we'll explore the implications of polyurethane adhesives, their benefits, the chemistry behind them, and the implications of the REACH polyurethane regulation.

Polyurethane: A Brief Overview

Polyurethane adhesives have been known for many years for their versatility, and offer superior adhesion to plastics, metals, and composites. Widely recognised for their toughness, high peel strength, and suitability for gap filling, these adhesives find application in various sectors. Outdoor usage is common due to their resilience against impact, solvents, weather, and abrasion.

Applications of Polyurethane in the Construction Industry Requiring Mixing and Curing

Polyurethane Sealants: Used for sealing joints and gaps in buildings to prevent air and water infiltration. These sealants often come in two-component cartridges that require mixing before application.

Duct Sealing: DIY type cans of expanding foam, and more engineered versions mixed within a bag or cartridges are used to seal cable ducts against water & gas. A cheap alternative that doesn’t work, and of course is carcinogenic to humans.

Cable Jointing: Two-component bags of resin are used for casting and protecting electrical cable joints

Polyurethane Adhesives: Used for bonding construction materials, such as wood, metal, concrete, and plastic. They often come as two-component systems that need to be mixed before application.

Polyurethane Grouts: Used for filling and sealing cracks in concrete structures, stabilising soils, and lifting concrete slabs. Polyurethane grouts typically come in two-component systems that need to be mixed on-site.

Spray Polyurethane Foam (SPF): Used for insulation and roofing applications. SPF is applied as a liquid that expands and cures into a foam. It involves mixing two components (polyol and isocyanate) on-site during the application process.

Polyurethane Concrete Repair Products: This includes repair materials for damaged concrete structures, such as crack fillers, spall repair, and surface coatings. These products often involve mixing two components before application.

Polyurethane Coatings: Used for protective coatings on surfaces like floors, walls, and roofs. Some formulations require on-site mixing of components before application.

Polyurethane Mortar Systems: Used for flooring in industrial and commercial settings. These systems typically involve mixing resin and hardener components to create a durable and chemical-resistant flooring surface.

Polyurethane Injection Resins: Used for structural crack repair and soil stabilisation. These resins are injected into cracks or voids in concrete structures and may involve on-site mixing.

Polyurethane Concrete Raising Systems: Utilized for lifting and levelling sunken concrete slabs. The process involves injecting expanding polyurethane foam beneath the slab, and the components are often mixed on-site.

Polyurethane Formulations for Mold Making: In construction, polyurethane may be used for creating moulds for architectural elements. This involves mixing and casting the polyurethane material to form moulds.

Chemistry of Polyurethanes:

Polyurethanes result from the reaction between isocyanates and polyols, with additional components such as pigments, fillers, plasticizers, flame retardants, and UV absorbers. It's crucial to note the hygroscopic nature of polyols and isocyanates, as their reaction with moisture can lead to undesired foaming or bubble formation. Catalyst selection plays a vital role in either suppressing or promoting such reactions.

Isocyanates and Safety:

Diisocyanates, notably toluene diisocyanate (TDI) and methylenediphenyl diisocyanate (MDI), are primary components of polyurethane adhesives. While they are consumed (become inert) during the adhesive reaction, their handling before cure poses health risks, including skin irritation, chest tightness, and respiratory issues. Moreover, isocyanates include compounds classified as potential human carcinogens. CARCINOGENIC TO HUMANS

What happens when Polyurethane catches on fire:

When polyurethane burns, it undergoes a combustion process that involves the release of heat, smoke, and potentially toxic gases. The specific reactions and byproducts can vary based on the composition of the polyurethane and the conditions of the fire. Here are some general aspects of what happens when polyurethane burns


Polyurethane undergoes pyrolysis when exposed to heat, breaking down into simpler compounds due to the absence of oxygen. This process releases flammable gases, such as carbon monoxide, carbon dioxide, water vapour, and various volatile organic compounds (VOCs).

Toxic Gas Emissions:

The combustion of polyurethane can release toxic gases, including isocyanates. Isocyanates are a component used in the production of polyurethane, and their release during combustion can pose health risks, especially if inhaled. These gases can cause respiratory irritation and other health issues.

Smoke Generation:

The burning of polyurethane produces dense smoke, which can significantly reduce visibility and make evacuation difficult in case of a fire. The smoke may contain particulate matter and other combustion byproducts that can be harmful when inhaled.

It's important to note that the combustion behaviour can vary depending on the specific type of polyurethane, its formulation, and the conditions of the fire. Additionally, the presence of other materials in the vicinity can influence the overall toxicity of the smoke and gases released during the burning process.

New REACH Restrictions:

The European Parliament's review led to the implementation of REACH restrictions on aliphatic and aromatic diisocyanates, effective from August 24, 2023. These restrictions necessitate training for all professional and industrial users dealing with products exceeding a total monomeric diisocyanate concentration of 0.1%. Adhesives and sealants manufacturers must provide safety training information and label products accordingly.

New Labelling Requirements:

Products sold within the EU and UK with a total monomeric diisocyanate concentration greater than 0.1% intended for professional or industrial use must have the statement below on the product container label by 24th February 2023:

'As from 24th August 2023, adequate training is required before industrial or professional use’.

This sentence should be visibly distinct from the rest of the label information.

Implications for Employers:

Under the new requirements, employers are tasked with offering adequate training for employees handling substances containing diisocyanates. The format of training is not specified, and many online courses are available. The Association of the European Adhesive & Sealant Industry (FEICA) supports its members with financial aid for training material related to polyurethane adhesives and sealants applications.

Are there alternatives that AC Cable Solutions Manufactures and supplies:

When it comes to alternatives for sealing cable ducts, such as Duct Sealing Systems, AC Cable Solutions manufacture Non-hazardous curing compounds that require no hazardous warning labels, and contain zero MEKO – The following Blogs will help you choose an alternative to Polyurethane based duct seals

What Duct Sealing Should i Use?


Correctly Specifed Duct Sealing Systems




This is simple when it comes to sealing cable ducts, DON'T USE POLYURETHANE 


Written by Carl Pike - The Duct Sealing Man 

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