Respiratory Protection

A hard hat that sits a little loose still stops a falling bolt. A respirator that sits a little loose stops nothing — air takes the easy path, and that's the gap at the edge, not through the filter. So "I'm wearing a mask" and "I'm protected" are not the same sentence.

The hazard

Different jobs put different things in the air, and no single filter stops all of them. Silica and drywall dust, welding fume, wood dust, mould in a gutted basement, solvents and spray paint, isocyanates off spray foam, diesel exhaust in an enclosed space — each needs protection matched to it. Wear a dust mask against solvent vapour and you'll smell the solvent right through it, and that smell is the dose reaching your lungs. Most of this damage builds slowly and quietly, so a mask that feels "good enough" is no proof it's doing anything at all.

The respirator is the last line — and it isn't yours to pick

Get this part right and the rest follows. Ventilation, water or a vacuum at the source, and keeping people out of the cloud come first; where those aren't practicable, suitable respiratory protection is provided for the hazard. When a respirator is genuinely the answer, the selection is made by your employer's written respiratory program for that specific task — not chosen off a chart, and not chosen at the truck.

Choosing correctly depends on things you can't judge by looking: what the contaminant actually is, its concentration, its occupational exposure limit, whether there's enough oxygen, whether the atmosphere could be immediately dangerous to life or health, the assigned protection factor needed, and what a given cartridge can and can't hold back. That's why it's a program, and why the answer can be very different for two jobs that look the same.

What the program has to give you before you put one on: a hazard assessment for the task, the specific make and model selected, confirmation you're medically able to wear it, training, a fit test for that exact make, model and size, and a defined change schedule for filters and cartridges.

• Never work out an unknown atmosphere with a cartridge. Confined spaces, sandblasting, oxygen-deficient or unidentified air need supplied-air or SCBA, determined before entry as part of the entry plan. If nobody can tell you what's in the air, the answer isn't a better mask — the answer is that the job doesn't start.

Make it seal, and know when it's spent

• Get fit-tested for the exact make, model, and size you'll wear — a face that seals one brand can leak on another. Follow your program's retest interval; don't assume a test from an old job still counts.
• Seal-check every time you put it on: cover the filters, breathe in, feel the mask pull to your face. Breathe out and feel for escape around the edge.
• Be clean-shaven where the mask seals. Stubble is the number-one reason masks leak — even a day's growth breaks it.
• Change filters and cartridges on the program's schedule, or on the end-of-service-life indicator. Don't wait until you smell or taste something. Plenty of contaminants have poor warning properties — you can be well past the limit with nothing to notice, and by the time you smell it, it's already through.
• Change sooner than the schedule if breathing gets harder, the filter is wet or damaged, or the mask is contaminated.

Watch out for

• A beard, stubble, or long sideburns under the sealing edge — no seal, no protection, whatever the respirator cost.
• The wrong cartridge for the job: a dust filter against vapour, or an organic-vapour cartridge that's already used up.
• Odour used as the change-out signal. It isn't one.
• A respirator tossed loose in a dusty truck or toolbox — you breathe whatever settled inside it. Bag it clean and dry.
• Reaching for a respirator to tough out a job we should be ventilating or doing a different way. The mask is the backup, not the plan.

Talk it over

• For today's airborne hazards: what does the program actually specify — the make, the model, and the cartridge — and does everyone have that, not just any mask?
• Who's been fit-tested for what they're wearing, and who's overdue?
• What's our change schedule for these cartridges, and how does anyone know when one is spent?