| 59


with special formulations/additives to qualify as a flame retardant and delay the effects of being exposed to open flame. There are five categories of flame retardants. Our technology group here at Zeroignition has thoroughly investigated each one to see how well it performs both in terms of fire safety and ecologically.


1. Halogenated flame retardants: Commonly used in the electronics, construction products, textiles and coatings industries. Here, bromines are used because when heated the bromine atoms essentially quench the chemical reactions occurring within the flame. This quenching can prevent the burning process from initiating, or slow it such that other measures can be taken to extinguish the fire.


One major issue with this type of flame retardant is they are becoming increasingly restricted for addition to materials because of safety concerns.


Conventional halogenated flame retardants are suspected of being harmful to health and the environment. Non-harmful replacements are therefore called for in most countries and other countries ban these types of fire retardants.


This is the one category that industry should completely move away from, as the release of chemicals in a fire can be very toxic and detrimental to the health of individuals.


2. Inorganic flame retardants: Found in paints, adhesives, wires and cables, and fabric coatings. A variety of inorganic compounds are used, but the most common are hydrated aluminium and magnesium oxide, and they are often combined with the other fire retardant classes. Inorganic fire retardants slow down the process of decomposition and release of flammable gases.


Because these inorganic flame retardants need to be combined with other types of flame retardants, such as halogenated fire retardants, they can cause environmental and health issues.


3. Nitrogen flame retardants: Melamine- based products are the most commonly used type of nitrogen flame retardants. When melamine is in the condensed phase the molecular structures transform into cross-linked structures. This transformation promotes the formation of char, which blocks the oxygen supply to feed the flame. The main common advantages of nitrogen flame retardants are their low toxicity; their solid-state; and, in case of fire, the absence of dioxin and halogen acids as well as their low evolution of smoke.


Since high quantities of these types of flame retardants are added to give the required fire retardant performance, these additional levels change many of the


Above left: Barriers to building with timber would be removed with effective fire retardant treatments PHOTO: ANDERS VESTERGAARD JENSEN/UNSPLASH


Above right: Fire retardant treatments have to be environmentally friendly to be sustainable PHOTO: OLGA KONONENKO/UNSPLASH


www.ttjonline.com | May/June 2021 | TTJ


characteristics of the material protected and thus are not the optimum flame retardant for many applications.


4. Intumescent coatings: When exposed to the heat from a fire, these coatings expand significantly to create a fire-resistant and insulating layer on the material surface. That layer protects the material from high temperatures, which can prevent or slow structural damage by deformation from the heat.


The effectiveness of intumescent flame retardants is due to the foamed char formed on the surface of the material that is exposed to a fire. The char acts as a physical barrier against heat transfer to the surface of the combustible material. Char formation lowers the rate of temperature increase of the surface beneath the char.


These types of flame retardants are developed for specific applications that provide fire retardancy but offer no room- temperature thermal protection or insulating properties. Again, these types of flame retardants have specific applications where they may be desirable but they are not universally applicable.


5. Phosphorus flame retardants: Science proves this is the most environmentally friendly category and forms the basis of Zeroignition’s product portfolio of fire retardant additives. Phosphorus flame retardants both chemically bond to materials and are also physically incorporated as an additive. A char is formed when the phosphorous compound is heated, thereby inhibiting the formation of combustible gas


and inhibiting the pyrolysis process (the process of chemically decomposing organic materials at elevated temperatures in the absence of oxygen).


What is particularly interesting about the formation of char is it hinders the release of combustible gasses while also forming a thermally protective layer that shields the protected material from the heat of the flame. These flame retardants are considered environmentally friendly and are great at promoting a char formation when exposed to a flame source. They also generate far less smoke compared to all other fire retardant categories. Innovation of products using this retardant is coming, and it’s only a matter of time before they reach the open market.


INNOVATION IS IMMINENT As we edge ever closer to that 2050 net- zero target, manufacturers and specifiers are likely to favour companies who can help them become more environmentally friendly. Solid wood, capable of being properly fire protected, would be more widely used as a result. To achieve this, the industry is crying out for an effective non-toxic fire retardant that stops the wood from burning and therefore reduces damage to the environment. With this in place, the use of natural building materials, such as wood would be promoted and encouraged.


The hard work has begun, people are listening and they’re looking for ways to adapt and change their building techniques. This is encouraging. Now the innovation must cut through, and this is where we, at Zeroignition find ourselves at the forefront. ■


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85