Allergy and Asthma Triggers in Customer Homes

Why this matters

Every house a tech walks into has its own air, and some of it is loaded: a closet carpet full of cat dander, a damp basement, a kitchen sprayed with fragrance an hour before the appointment. For most techs that is a sneeze. For the one on your crew with asthma it can be a tight chest by the second job and an emergency room by the fourth, and for the customer with asthma, the dust your work kicks up is the thing they will remember about your visit. The cheap protective habits exist, but nobody uses them if nobody knows which houses and which tasks carry the load.

Three different things that all make you wheeze

These get lumped together and they behave differently, which matters for what protects you.

• An allergen triggers an immune response in people who are sensitized to it: dust mites, pet dander, cockroach and rodent proteins, mold spores, pollen. A non-allergic tech can roll around in it and feel nothing. A sensitized one reacts to tiny amounts.
• An irritant inflames the airways in anyone at high enough concentration, and in an asthmatic at much lower concentration: fragrance and air fresheners, cleaning-product vapors, bleach, combustion fumes from a gas range or a backdrafting water heater, fiberglass fibers, plain dust.
• A sensitizer is a substance that can create a new allergy, sometimes after months of uneventful exposure, and once it has, tiny exposures set it off for good. Some appear in field work: the isocyanates in spray foam and some coatings, some disinfectant chemistries, certain adhesive components. This is how a tech with no history develops occupational asthma, a form of asthma caused by something at work.

The practical fork: particle filters help with allergens and dust, they do nothing for vapors and fragrances, and nothing short of not being exposed helps reliably once someone is sensitized.

Where the load sits in a house

Two field facts change how you plan. Cat allergen outlasts the cat. It is light, sticky and clings to fabric and ductwork, so a house where the cat left months ago can still carry a heavy load. And ductwork collects all of it, which is why opening an air handler or pulling a return grille in a pet house is a bigger exposure than standing in the living room.

Droppings carry infection risk on top of allergen, which is a separate hazard: see related: Rodent Droppings and Hantavirus for the Trades.

The tech with asthma

Rescue inhaler on the body, not in the truck. A rescue inhaler (a short-acting reliever) is only useful within reach. A tech in an attic whose inhaler is in the van console has to climb down a ladder short of breath, which is the worst way to make that trip. Shirt pocket or belt pouch, every job.

Someone on the crew knows. Disclosure is the worker's choice, and you cannot require it. But a tech who has told the lead "I have asthma, the inhaler is in my left pocket, if I cannot talk get it for me" has turned a medical event into a two-minute pause. The shop's part is making that easy to say without it becoming a question about whether they keep the job.

Know when it is an emergency. Call 911 when a rescue inhaler used as the person's own plan directs is not helping, when they cannot speak a full sentence, when lips or fingernails look gray or blue, or when they become drowsy or confused. Get them out of the exposure into fresh air while you wait. Beyond helping them use their own medication, this is not first aid you improvise.

Task assignment is the lever. The heavy-exposure tasks are predictable: attic insulation work, duct cleaning, pulling carpet, cutting moldy drywall, spray foam anywhere nearby. Rotating an asthmatic tech off the worst of them, or giving them the outside half of the job, costs a lead a minute of planning.

Respirators: what they do and what they do not

A filtering facepiece such as an N95 catches particles: dust, dander, mold spores, fiberglass. It does nothing for gases or vapors, so it will not stop fragrance, bleach or solvent fumes. A half-face respirator with organic-vapor cartridges handles some vapors, and with particle filters added covers both, but it is a heavier piece of equipment with real breathing resistance.

The law layer here is federal, at 29 CFR 1910.134. When an employer requires a respirator, the standard requires a written respiratory protection program, a medical evaluation before the worker is fit-tested or uses it, and a fit test before first use and annually after. When a worker wears a filtering facepiece voluntarily where none is required, the employer must give them the information in Appendix D of the standard. For an asthmatic tech the medical evaluation is not paperwork: a respirator adds breathing resistance, and the evaluating clinician is the person who decides whether that is safe for them. States running their own OSHA plans adopt at least this floor.

A respirator that does not seal does little. Beards, wrong size and a strap pulled over a hat brim are the common ways a mask becomes decoration.

The customer with asthma

The other half of the exposure is the one you create for the household. A furnace replacement, a drywall patch or a duct job can leave a fine dust behind that triggers a child's asthma for days. The office can ask at booking and the tech can confirm at the door:

OFFICE:   Anyone in the home with asthma or bad
          allergies we should plan around?
CUSTOMER: My son has asthma. Is that a problem?
OFFICE:   Not at all. The tech will close off the
          work area and run the vacuum with the good
          filter, and he won't use any sprays. Is he
          home during the day?
CUSTOMER: He's at school till three.
OFFICE:   Great, we'll aim to be done and cleaned up
          before then.

TECH (at door): Your office notes say your son has
          asthma. I'll keep this door shut and clean
          as I go. I'm swapping the filter today,
          want me to leave the old one bagged?

The concrete practices behind that script: close the work area off with a door or sheeting, vacuum with a HEPA-filtered vacuum rather than sweeping, mist dust down before cleanup rather than blowing it, bag removed filters and insulation at the point of removal, do not use fragranced cleaners or sprays, and replace the air filter at the end of any work that disturbed the duct system.

A worked example

A tech with mild asthma, well controlled, has two calls on a Thursday. Call one is an air handler service in a house with three cats; the unit sits in a carpeted closet that doubles as the litter box room, and the return runs through the closet. Call two is a thermostat swap in a newly cleaned condo.

Call one is the exposure. Opening the air handler and pulling the return filter disturb exactly the reservoir where dander collects. The lead's planning, in order: the tech confirms the inhaler is in a pocket before going in. The tech wears an N95, and because the shop's program has already had him medically evaluated and fit-tested for it, that is a straightforward choice. The filter goes straight into a bag. He keeps the closet door open to the hall with a fan blowing out, not in, so he is not working in a sealed box of dander. About 40 minutes in, his chest feels tight. He stops, steps outside, uses his inhaler, and waits. In ten minutes it has eased and he can talk normally, so he finishes the last 15 minutes of the job with the helper doing the filter-side work.

Now change one condition. Suppose the tight chest had not eased after his inhaler, or he could not finish a sentence. That is the 911 threshold above, regardless of how mild his asthma usually is, and the helper calls rather than driving him in.

Call two looks harmless and is the one that surprises people. The condo was just cleaned with a heavily fragranced product. His N95 does nothing for it, because fragrance is a vapor. The fix is ventilation and timing: windows open while he works, the swap done in 20 minutes, and next time the office asks the customer not to run the fragranced cleaning on the morning of a visit.

The failure version: the tech skips the mask because the closet "doesn't look dusty," leaves the inhaler in the truck because it is one floor down, and wheezes his way through two hours rather than admit to the helper he is struggling. The tightness was predictable from three cats and a carpeted closet.

The law layer for the worker

At the federal level, the Americans with Disabilities Act reaches employers of 15 or more and can require a reasonable accommodation for a worker whose asthma is a disability, such as adjusted task assignments; it also bars asking about a disability before a job offer is made. State laws often reach smaller shops: California's covers employers of five or more, and New York's covers employers of any size. For a specific accommodation question, talk to an employment attorney or your state's civil rights agency with the worker's request in writing. This is not legal advice.

How to verify your crew is covered

• Every tech who carries a rescue inhaler can show it on their person at a random job, not in the truck.
• The office's booking script asks about asthma and allergies, and the answer appears on the work order.
• Any required respirator use is backed by a medical evaluation and a current fit test on file under 1910.134.
• After a disturbing job, the customer's air filter was replaced and the work area was HEPA-vacuumed, both noted on the ticket.

References

• OSHA, Respiratory Protection standard, 29 CFR 1910.134, including Appendix D
• NIOSH, work-related asthma and isocyanates guidance
• EPA, Asthma Triggers: Gain Control (indoor allergens and irritants)
• US EEOC, ADA guidance on reasonable accommodation
• See related: Mold Exposure for Trades Who Are Not Remediators