Exotic or Toxic: The Science Behind Epoxy and Polyurethane Coatings | Blog Post #7
Polyurethane Topcoats: Toxic & Harmful!
Is your new Metallic Epoxy Singapore coated surface toxic, and are you being exposed to harmful polyurethane particles in your homes right now?
Fact Or Fiction?
In the digital age, many consumers are highly resourceful and take great pains to research a product and its alternatives before sealing the deal. Often, the decision hinges on factors such as the suitability of the product for one’s needs, or its value for money. However, the one factor that a smart consumer should NEVER compromise on is: Safety.
In today’s post, we’ll be exploring the safety of metallic epoxy coatings for your home and office. As with any product, there are bound to be rumours — many entirely unsubstantiated and a few misinterpreted — about potentially harmful side-effects of a product. The surest way to make an educated decision, free of sensationalised news and half-truths, is to have a personal understanding of the product and the science behind it from neutral sources.
For the casual reader, this post will condense and simplify relevant scientific research on the safety of epoxy coatings and all that they entail. For the more avid reader, we will be including our sources, from government and research organisations, to more thoroughly equip you in making an educated decision.
What’s In My Epoxy Coating?
A good epoxy coating is far more than a single slab of solidified epoxy. Most coatings consist of three main layers — the base coat, the body coat, and the top coat — each of which serve crucial functions.
The base coat consists of a layer of sealant and primer to form a clean base that the epoxy can adhere to. It also prevents moisture and air from entering beneath the finished epoxy coating.
The body coat makes up the bulk of the epoxy coating. It consists of a liquid epoxy resin mixture of approximately 55% epichlorohydrin, 45% Bisphenol A (BPA), and small amounts of an alcohol hardener. When poured and spread, the alcohol hardener eventually harmlessly evaporates, while the epichlorohydrin and BPA react in the curing process to form solid epoxy.
The top coat may vary across suppliers, but often consists of an oil-based or water-based polyurethane coating. Polyurethane coatings can contain one of two types of polyisocyanates — aromatic polyisocyanates or aliphatic polyisocyanates. The former is more cost-effective and suitable for indoor use, while the latter is more expensive but weathers ultraviolet degradation better.
Now that we’ve started listing complex technical terms, let’s explore what each one means. In much the same way that your mobile phone or high-end headphone uses heavy metals, epoxy coating application is an industrial process that uses compounds that could be dangerous on their own. However, in the same way that mobile phones don’t poison you each time you take a call, epoxy coatings are designed with the intention to render these compounds entirely harmless for everyday use.
The Truth In Numbers
Big claims need strong numbers, especially when there are lives at stake. Here, we focus on the components that could pose health risks — and why they don’t.
Bisphenol A (BPA)
A prime example would be BPA — this boogeyman of the plastic industry has earned a bad reputation in consumer plastic products, and rightfully so. Following studies that linked the presence of BPA in food and drink to an increased risk of cancer, many companies began changing their products, such as water bottles and lunch boxes, to be entirely BPA-free
“But you mentioned that almost half of my epoxy coating is made of BPA, are you trying to give me cancer?!”
No! Besides being a terrible business model, it would certainly be ethically unsound. When epoxy resin is poured and spread, the BPA and epichlorohydrin react almost completely to form a solid epoxy material. The ratio of each compound in the mixture is prepared with safety in mind — in modern epoxy resins, the amount of unreacted BPA remaining is less than 1 part per million (ppm), far below the estimated maximum of 10 ppm.
All that, and we haven’t touched on the most relevant point — the epoxy body in a coating, if installed properly, will never even be exposed at all. Instead, all the abuse of everyday use is borne by the polyurethane top coat, the focus of the next section.
Polyurethane Top Coats (And Why You Shouldn’t Worry)
Polyurethane, sometimes mistakenly called urethane, is a durable compound often used as a protective coating for paints, wood, and in this case, an epoxy body. Strong, modern polyurethane coatings contain a group of compounds known as polyisocyanates. Polyisocyanates are harmful and present as emissions from liquid polyurethane mixtures — in higher concentrations, they can cause respiratory problems and skin problems when physically contacted. However, what make polyisocyanates harmful also make them useful — their reactive nature allows them to bond readily with alcohol, amines, or water, meaning they react quickly and completely. As such, the only time when there is any significant presence of harmful polyisocyanates is during the curing process. After the top coat hardens and cures, any emission drops to virtually zero, protecting your epoxy coating in a safe and efficient manner.
Justifiable Concern and Irrational Worry
Here at Metallic Epoxy Singapore, we believe in a constructive feedback loop. If something is inadequate with a process, we identify the issue, check the numbers, implement a solution, and check the numbers again. If it doesn’t work, we’re right back to the drawing board to find a solution.
In the same spirit of constructive progress, we urge you to take education into your own hands. If you hear something bad on the grapevine — it could be about polyurethane coatings, brain-melting mobile phone emissions, or even mutant chickens being used at your favourite fried chicken franchise — do the research and verify the facts. More often than not, you’d come out ahead as a well-educated consumer and a responsible member of society.
Our team believes in the safety of our products and services, and the moral responsibility to ensure they remain so. If you’ve any questions or concerns about our process, feel free to drop us a message or give us a call for a better understanding how we can help you build your dream home or office.
Learn about the different types of topcoat finishings Metallic Epoxy Singapore offers and their uses in our previous post: “Flaunt or Fend: Choosing The Right Topcoat For You | Blog Post #4”
Or find out why our Metallic Epoxy coatings should be your go to choice for your homes and workspaces in “Walking the Path Less Taken: Metallic Epoxy VS Conventional Materials | Blog Post #3“