What respirator works if you have a low nose bridge?

This comes up constantly and it is usually answered with the wrong advice: try a smaller size, tighten the straps, add a nose foam.

The problem is geometric. A sealed respirator works by pressing a gasket against a continuous ring of skin. That gasket is moulded to a face shape, and if the bridge of your nose sits lower or flatter than the mould assumes, the gasket bridges the gap instead of following it. Tightening the straps pulls harder on the parts that already touch; it does not close the part that does not.

Two tells that this is your problem rather than a fitting error: your glasses fog constantly, and you can feel a draught at the top of the mask when you inhale sharply.

The alternatives are the same ones a beard leaves you: a mask genuinely sized for your face, which is worth trying, or a powered hood, which does not seal against the face at all. In a powered unit the blower pushes filtered air into the hood and out past your face, so the fit question disappears and no fit test is involved.

Worth being clear that this is about a seal, not about protection quality. A well-fitting sealed mask is a perfectly good respirator. The issue is that a great many faces do not fit the moulds on offer.