There’s no denying that WD-40 is a useful, versatile lubricant, but it’s also a solvent, and there are some places you should never use it. That’s because it doesn’t have the same viscosity as traditional grease or oil and can erode certain finishes. Here are some places you should definitely never use WD-40.
Plastic: If you’re trying to lubricate a hinge on a pair of sunglasses or remove a price tag from the surface of a plastic container, you might be tempted to reach for WD-40, but don’t. Because of the chemical makeup of WD-40, it can cause damage to these plastics and ruin things like sunglasses and plastic lenses.
Wood: WD-40 can dissolve wax finishes, which is why you should always be careful to keep it clear of wood floors and furniture. Because WD-40 can seep into the grain of unfinished wood, it’s generally not a good idea to use it on any wood surface.
Natural Stone: Natural stone is porous, which is why you should never use WD-40 to clean it or remove something from it. WD-40 can soak into the surface of the stone and stain it. In addition, many stone surfaces are treated with wax polish, and WD-40 can dissolve wax finishes.
Food Prep Surfaces: Some appliance companies recommend using WD-40 to clean stainless steel, but you should never use it on surfaces that will be used for food preparation. While a streak-free shine is a powerful motivator, WD-40 obviously shouldn’t be consumed, and while incidental contact with food isn’t a big deal, surfaces where food is in frequent or prolonged contact should never have WD-40 on them.
Electronics: You should never use WD-40 on electronics, which can react with some plastics as well as attract dust and other particles. Getting WD-40 on your smart phone or laptop can not only damage the screen, it can ruin the buttons or make its way into internal components.
Arthritis Pain: This should be obvious, but unfortunately requires saying: In spite of persistent claims to the contrary, WD-40 will not help relieve arthritis pain or creaky, stiff joints. While there are plenty of ways that WD-40 can help lubricate things, your joints will not respond to it in the same way as a stuck bolt. Human bodies don’t use the same lubricant as engine parts, and medical professional warn not to use it to treat any type of medical condition.
