A respirator is a bit of prep most people only think about when the air is already bad — wildfire or moorland smoke drifting over a town, dust and mould during a flood clean-up, sanding or clearing debris after a storm, or a public-health scare. A cloth or surgical mask does almost nothing against fine particles; what you want is a proper FFP-rated respirator that seals to your face. FFP3 filters the most (at least 99% of fine particles) and is the sensible default for clean-up and smoke; FFP2 is a lighter, cheaper option for dust and general nuisance particles.
The picks split by how often you'll use one. For a genuine seal and comfort over a long clean-up, 3M's Aura folds flat and is widely regarded as the benchmark FFP3 — we've led with it, with a valved JSP box and a good-value AirGearPro 20-pack as stock-up alternatives. For lighter dust jobs the Aura FFP2 does the job for less. If you'll be doing this regularly — recurring building, garden or flood work — a reusable half-mask like the Stanley P3 works out cheaper and greener than disposables over time, as you only replace the filters. Fit matters more than brand: a respirator only protects if it seals, so check it against your face and note that heavy facial hair breaks the seal on any of them. Every pick here is a real, in-stock catalogue product.