 Do novel materials present novel risks? Novelty is a big part of advanced materials, not novelty in terms of amusement of course, although the inventors of silly putty may beg to differ, but novelty is in something that's new or unusual. If you can design an engineer a material that behaves differently to other materials, you open the door to improving existing products and inventing exciting new ones. If you get it right, you could make a financial killing. But novel materials can also help find solutions to some really stubborn challenges like ensuring everyone has enough food and water and energy for instance. This is fantastic. As long as your fancy new material doesn't create more problems than it solves. But here's the rub. How do we know that these novel materials don't come pre-packaged with novel risks? On the surface, the question makes a lot of sense. If a material is designed to behave in unusual ways, who's to say that that unusual behavior won't lead to unusual biological impacts that in turn lead to unusual harm and unusual diseases? However, this is also a somewhat misleading question and here's why. From a human health perspective, we're interested in risk. What can cause harm? How does it do it? How much harm could potentially be caused? And how can we reduce or avoid this? As far as our bodies are concerned, they couldn't care less about whether a risk is novel or not. They're just interested in whether something is going to hurt and how to avoid that hurt. For instance, if you hit your thumb with the latest Nanocomposite Metamaterial Superhydro Whatever Hammer, the instrument of destruction may be highly novel but the pain will be the same as if you'd used your grandmother's anti-nail wacker. The novelty is in the hammer but not in the harm it causes. The danger here is that focusing on novelty rather than risk diminishes the importance of the actual harm that a material could cause. It implies that the only interesting risks are the new and unusual ones. And it ignores the reality that many common risks associated with materials novel or otherwise remain highly important and poorly understood. When it comes to novel materials and advanced materials more generally, a much better question is can this material potentially cause harm? Follow quickly by under what circumstances, what type of harm, how much and how can it be avoided? These questions focus on impact rather than novelty and recognize that many novel materials may in fact present rather mundane risks that nevertheless still need to be dealt with. Of course, there's still the chance that a novel material will do something entirely and expected if it gets into your body. As last week's Risk Bites highlighted, this is where we need scientists asking the difficult questions just in case something new does come up. But until it does, fixating on novel risks runs the risk of overlooking the more boring risks that are likely to be a problem unless dealt with. Next week, the last in this series looks at turning risk on its head and asking whether understanding potential health impacts can actually help us design better advanced materials. Until then, stay safe.