In recent years there has been a growing shift towards using halogen-free materials in electrical systems and components. This trend is driven by increasing awareness of safety, sustainability, and stricter regulations on hazardous substances. But what exactly does it mean for a product to be “halogen-free”, and why does it matter for electrical installations? In this article, we explain what halogens are, why traditional plastics like PVC are being reconsidered, and how halogen-free compounds improve fire safety and environmental performance.
We’ll also compare halogen-free materials with standard PVC (a halogenated material) and highlight where these materials are commonly applied in the electrical industry. By the end, you’ll understand the key benefits of halogen-free electrical products and the reasons they are becoming an essential choice for safer, greener installations.
What Are Halogens and Why Should They Be Avoided?
Halogens are a group of chemical elements – including chlorine, bromine, fluorine, iodine (and the rare astatine) – which for decades have been used in plastics and electrical components. The most familiar example is PVC (polyvinyl chloride), a plastic made with chlorine that has been widely used for cable insulation, conduits, and equipment housings because of its excellent flame-retardant properties and durability. Bromine compounds have also been used as flame retardants in electronics. These halogen additives help materials resist fire and heat, improving safety under normal conditions.
However, halogens have a serious downside when things go wrong. In the event of a fire or when a material is exposed to high temperatures, halogenated compounds can release highly toxic and corrosive gases. For instance, burning PVC can emit hydrogen chloride (HCl) gas, and brominated plastics can emit hydrogen bromide – both of which form caustic acids on contact with moisture. These fumes pose a severe danger to human health (causing respiratory damage or worse during a fire) and can corrode nearby metal parts and electronic circuits, worsening the damage to equipment. In enclosed spaces, dense smoke from burning halogenated materials also reduces visibility, hindering evacuation and firefighting efforts. Additionally, the presence of halogens in plastics can make recycling and disposal more problematic, as they can contaminate recycling processes and produce hazardous by-products if not handled properly.
Due to these risks, there is a strong incentive to avoid halogens in materials where possible. Both health and environmental regulators have introduced measures to limit the use of certain halogenated substances. In the electronics sector, for example, regulations like RoHS (Restriction of Hazardous Substances) and REACH (Registration, Evaluation, Authorisation and Restriction of Chemicals) restrict the use of some brominated flame retardants and other hazardous additives. This has pushed manufacturers to seek safer alternatives that do not contain chlorine or bromine. The solution has been the development of halogen-free compounds which can achieve similar (or even better) flame resistance and material performance without relying on those harmful elements.
What Does “Halogen-Free” Mean?
A product is considered “halogen-free” if it meets strict limits on halogen content defined by international standards. One widely referenced benchmark is IEC 61249-2-21, which specifies that a material must contain less than 900 parts per million (ppm) of chlorine or bromine, and less than 1500 ppm of total halogens, to be classified as halogen-free. In simpler terms, any traces of halogen elements are kept to extremely low levels. For comparison, a traditional PVC compound is heavily loaded with chlorine (often well over 20% of its weight is chlorine), far exceeding those limits. Halogen-free materials replace chlorine- or bromine-based additives with other flame retardant formulations (such as metal hydroxides or phosphorus compounds) to achieve fire safety without the nasty side effects.
Meeting the halogen-free standard is about more than just numbers – it is about ensuring that if a material burns or decomposes, it will not release significant amounts of toxic halogenated fumes. By keeping chlorine and bromine content negligible, halogen-free products dramatically reduce the production of acidic smoke in a fire. This makes them safer for people (less toxic inhalation risk) and for property (less corrosion of electronics and structures). Additionally, halogen-free materials tend to burn cleaner, producing a lighter-colored smoke that improves visibility during evacuation. From an environmental perspective, using halogen-free compounds facilitates more sustainable waste handling and recycling. Since these materials don’t contain chlorine or bromine, they avoid contaminating recycling streams with halogenated residues, allowing plastics to be recycled or disposed of with lower pollution risk.
It’s important to note that “halogen-free” does not mean the material is non-flammable or safe from fire – rather, it means that if it does catch fire, it will burn without releasing halogen-derived toxins. Many halogen-free electrical materials are also designed to be flame-retardant or self-extinguishing, but using different chemistries that comply with safety standards (for example, some halogen-free cable insulations meet the same fire safety ratings as PVC, but without chlorine). In the cable industry, the term LSZH (Low Smoke Zero Halogen) is commonly used to describe insulation or sheath materials that produce minimal smoke and no halogenated gases in a fire. LSZH cables are now often required in sensitive installations like tunnels, rail networks, and commercial buildings in the UK and Europe for enhanced fire safety.
Benefits of Using Halogen-Free Materials
Switching to halogen-free materials in electrical installations brings a number of significant technical and environmental advantages. Below are some key benefits:
Lower Toxic Smoke Emissions
In case of a fire, halogen-free materials emit far less toxic and corrosive smoke than their PVC or bromine-containing counterparts. The smoke from halogenated plastics like PVC is not only thick and black, reducing visibility, but also laced with acidic gases that can harm anyone who inhales it and corrode metal surfaces. By contrast, halogen-free products produce “low smoke” that is clearer and free of chlorine or bromine compounds, which means less hazard to people and less damage to equipment during a fire. This property can be life-saving, improving the chances for safe evacuation and reducing post-fire cleanup and corrosion issues.
Easier Recycling and Sustainability
An often overlooked benefit of halogen-free compounds is their improved recyclability. Plastics containing halogens (especially mixed plastic waste) require special handling because of the risk of releasing toxins during reprocessing. Halogen-free plastics simplify the recycling process – they can be more readily processed without producing chlorine-based acids or dioxins. This supports a more circular economy where materials from old electrical equipment can be safely recovered and reused. Additionally, manufacturers opting for halogen-free ingredients are often also formulating their products to be more environmentally friendly in general (using fewer hazardous additives). The move to halogen-free goes hand-in-hand with the broader push for sustainable, green electrical products that minimise environmental impact over their life cycle.
Compliance with Safety Regulations
Using halogen-free materials makes it easier to meet present and future regulations in the electrical and electronics industries. Around the world, standards and directives are increasingly limiting the use of hazardous substances. For example, the European RoHS directive restricts many brominated flame retardants; the REACH regulation controls chemicals that pose risks; and fire safety standards (such as IEC 60754 for cables and UL 94 for flammability ratings) are emphasising low-smoke, low-toxicity performance. Many public projects and building codes now explicitly require LSZH or halogen-free cables in certain areas, such as escape routes and critical equipment rooms. By choosing halogen-free products, manufacturers and installers ensure their equipment is “future-proof” in meeting strict fire safety and environmental standards without needing exemptions. In other words, halogen-free designs are aligned with the direction of modern regulations and avoid the risk of certain materials being banned or phased out in the near future.
Strong Technical Performance
It’s worth dispelling the myth that going halogen-free means compromising on quality or performance. Modern halogen-free materials often match or exceed the technical performance of traditional plastics. They can be engineered to have excellent thermal stability, mechanical strength, UV resistance, and long-term durability. For instance, many halogen-free cable jackets and enclosures are highly resistant to heat and do not degrade as quickly as older PVC formulations (which can become brittle over time or when plasticisers evaporate). In fact, several manufacturers report that their halogen-free product lines have equal or longer service life compared to legacy versions. By eliminating certain chemicals, the materials can even be more stable and less prone to issues like corrosion or electrical leakage. In summary, halogen-free does not mean lower quality – in many cases, it is an upgrade in both safety and performance, ensuring that electrical installations are reliable as well as safe.
Halogen-Free vs Traditional PVC: A Comparison
How do halogen-free materials actually stack up against the more common halogenated materials like PVC? The table below provides a side-by-side comparison of some key aspects:
| Aspect | Halogen-Free Materials | PVC / Halogenated Materials |
|---|---|---|
| Smoke toxicity & corrosivity in fires | Produce minimal toxic smoke and virtually no acidic gases. Smoke is less dense and does not corrode metal equipment, improving visibility and safety during a fire. | Produce dense, highly toxic smoke (e.g. HCl gas from PVC) that can suffocate and poison people. The acidic fumes corrode nearby metal surfaces and electronics, exacerbating fire damage. |
| Environmental impact & recyclability | Easier to recycle and dispose of safely. Free of chlorine and bromine, so no toxic halogens are released during recycling or landfill, leading to cleaner waste management. | Difficult to recycle without special processes. Halogens can contaminate recycling streams and, if incinerated or dumped, may form harmful by-products (acids, dioxins) that pollute the environment. |
| Regulatory compliance | Comply readily with modern safety and environmental regulations (RoHS, REACH, etc.) without needing exemptions. Often already meet stringent fire safety standards (low smoke, zero halogen requirements). | Increasingly face regulatory restrictions. Some uses of PVC and brominated flame retardants are banned or limited by new regulations, requiring careful compliance management or replacement materials. |
| Fire retardancy performance | Can achieve high flame-retardant ratings using alternative additives (e.g. aluminum hydroxide, phosphate compounds). Many halogen-free cables and components are self-extinguishing and meet flame tests comparable to PVC-based materials. | Often naturally flame-retardant (PVC is self-extinguishing due to chlorine). However, while they resist ignition, they release dangerous smoke and fumes when they do burn, which is a critical safety trade-off. |
| Material durability | Designed for equal or better durability: resistant to heat aging, UV light, and mechanical stress. Halogen-free plastics maintain their properties over time without leaching harmful chemicals. | Proven track record of durability, but can degrade (e.g. PVC may become brittle with heat or sun exposure over many years). May leach or bloom additives (like plasticisers) over time. Can produce corrosive gases if overheated. |
As shown above, halogen-free materials offer clear advantages in terms of fire safety and environmental friendliness, without sacrificing performance. The main historical advantage of PVC and similar materials was their inherent flame resistance and low cost. Today, however, the cost gap has narrowed and alternative flame retardant technologies have matured, making halogen-free products a smart choice in most applications. In scenarios where human safety and equipment protection are paramount, the benefits of halogen-free compounds far outweigh any remaining cost differences.
Where Are Halogen-Free Materials Used?
Halogen-free electrical products are increasingly being adopted across a wide range of sectors – anywhere that fire safety and toxic smoke reduction are concerns. Some common applications and settings where halogen-free materials are especially important include:
- Data centers and server rooms: These facilities contain dense electronic equipment that can be severely damaged by corrosive smoke. Using halogen-free cable insulation, electrical conduits, and enclosures helps protect sensitive servers and networking gear in the event of an electrical fire.
- Hospitals and public buildings: In places like hospitals, schools, airports, and shopping centres, large numbers of people need to be evacuated quickly if there is a fire. Halogen-free wiring and fixtures ensure that any smoke generated is less harmful to inhale and does not impair visibility as much, buying valuable time for safe evacuation.
- Transportation hubs and tunnels: Underground train stations, tunnels, and other confined transit environments have strict fire safety standards. Halogen-free cables (LSZH cables) are mandated in many such cases to prevent the release of toxic fumes. Similarly, trains, ships, and aircraft often use halogen-free materials in their electrical systems for the same reason.
- Industrial facilities and factories: Many industrial settings now prefer halogen-free electrical infrastructure, especially in areas with critical equipment or personnel. For example, factories installing new industrial sockets, control panels, or cable trays often opt for halogen-free variants to enhance overall safety. In harsh environments, the combination of halogen-free and also flame-retardant properties is ideal.
- Residential and commercial buildings: Even in everyday home and office construction, the use of halogen-free materials is on the rise. From halogen-free junction boxes and enclosures to low-smoke cables in high-rise buildings, developers are recognising the added safety value. Many modern building specifications explicitly call for low smoke zero halogen wiring in critical circuits, alarm systems, and emergency lighting.
In short, any installation that values fire safety, asset protection, or has to meet strict fire codes can benefit from using halogen-free components. The movement spans multiple industries – telecom, automotive, aerospace, and, of course, construction and electrical engineering. It’s not just a niche trend, but a broad shift towards safer materials. In fact, the adoption of halogen-free compounds is frequently highlighted as part of the sustainability and safety trends shaping the future of the electrical industry. Professionals and installers are increasingly expected to be familiar with these materials as they become the new normal in specifications.
How Can You Tell If a Product Is Halogen-Free?
With manufacturers now keen to market their products as “green” or “safe”, it’s important to be sure that a given item is truly halogen-free and not just using buzzwords. Here are a few tips for identifying genuine halogen-free products in the electrical field:
- Check the technical specifications: Reputable products will clearly state compliance with halogen-free standards. Look for phrases like “halogen-free material” or references to standards such as IEC 61249-2-21, or the label LSZH for cables. For example, many product datasheets or markings will indicate “Free of halogens: Yes” as part of their safety features.
- Look for certifications or standards: Verify if the product meets relevant regulations like RoHS (which, among other things, restricts certain brominated compounds) or has a UL94-V0 rating using non-halogenated flame retardants. Some international standards explicitly certify cable materials for low smoke and zero halogen content (for instance, IEC 60754-1/2 test for acid gas emissions). Products that pass these will usually advertise it, as it’s a selling point.
- Rely on trusted manufacturers: Choose brands or suppliers with a known commitment to safety and compliance. Established manufacturers will provide documentation – such as material declarations or test reports – confirming that their plastic compounds are halogen-free. They often have this information in product catalogs or on their websites. If in doubt, don’t hesitate to request a certificate of compliance or ask whether the item conforms to halogen-free requirements.
- Beware of partial claims: Terms like “low-halogen” are not the same as “halogen-free”. A “low-halogen” product might simply have reduced halogen content but not enough to meet the official threshold. Only “zero halogen” or “halogen-free” (within the defined ppm limits) guarantees the full benefit. Always read the fine print of what a manufacturer means by their terminology.
By doing a bit of homework on specifications and certifications, you can ensure that the components you are using or purchasing truly deliver the safety advantages of being halogen-free. This diligence is especially crucial for projects like large public buildings or infrastructure, where using an imitative product that still contains halogens could have serious implications in an emergency.
Solera’s Approach: Going Beyond Compliance
At Solera, we recognise that adopting halogen-free materials is not just about ticking a regulatory box – it’s about raising the bar for safety and sustainability in every project. That’s why we have taken a proactive stance in integrating halogen-free compounds into our product lines, even in cases where current regulations might not yet demand them. Many of our enclosures, junction boxes, conduits, and other ranges are made from halogen-free thermoplastics as part of our commitment to quality. This includes products for domestic use and heavy-duty industrial applications, all designed to offer enhanced fire safety.
Our philosophy is that each innovation in material science is an opportunity to improve outcomes for people and the environment. By using halogen-free materials, we aim to provide electricians and installers with peace of mind that the products they are installing will behave more safely under extreme conditions. We also see it as a contribution to environmental responsibility – facilitating recycling and reducing the harmful impacts of electrical waste. In our view, sustainability and safety go hand in hand, and specifying halogen-free compounds is a natural part of designing modern electrical equipment that meets those twin goals.
Solera’s development team works closely with certification bodies and follows the latest standards to ensure that our products don’t just remove hazardous substances, but also perform excellently in the field. The result is a range of offerings that installers can trust to meet high standards (for example, our “Blue Series” hollow-wall boxes are made of halogen-free material and 850°C glow-wire tested for fire resistance). We believe that choosing halogen-free is not a temporary trend but a lasting improvement in how electrical systems are built. By going beyond mere compliance and embracing these materials early, we aim to lead by example in our industry.
In conclusion, halogen-free materials are redefining what it means to build safe and sustainable electrical installations. They address critical fire safety concerns and environmental issues associated with older halogenated plastics, all while delivering robust technical performance. Whether you’re an installer, a project engineer, or an end user, it’s worth considering halogen-free options for your next electrical project – the benefits could be life-saving. As the industry continues to evolve with a focus on safety and eco-friendly design, Solera remains committed to providing the solutions and information needed to make informed, responsible choices.