In my case, I got occupational asthma form a one-time horrific incident that, according to my doctors, burned the mucous membrane off the entire body which the most serious organ is the lungs. This is different that a regular type of skin burn that is readily visible and well understood. most is 'inside." Another overall heading for occupation asthma is: Reactive airway dysfunction syndrome. and that is exactly what it 'feels' like all the time. Your lungs just don't work as they should. Doctors had said that oxygen is a treatment from day of injury, at least a small liter flow, otherwise other organs get 'overworked' and are affected. I'm not a doctor, just a 21+year patient of many well known doctors in the field. No cure until research allows for regrowing of lung tissue, etc. Toxic exposures can be low amounts on-going or a one-time bad injury event. Finding the specific toxic or chemical trigger is important. For us, one speaks in parts per billion, not million which are considered the safe amounts for one who is healthy. FDA has allowed us to be excluded form clinical trials and many inhalers and medications on the market  do more harm than good. And finding out what the inert ingredients are requires a phone call to the pharmaceutical company by the patient who has the legal right to know-doctor doesn't have that right. You ask them if it contains your list and they will usually tell you immediately or get back to you shortly. I've had them say: occupational asthma, our drug shouldn't be taken by you. There are some skin tests for which chemicals are the triggers. As far as I know, insurances won't pay for them. For me, they were very accurate and allowed me to know that formaldehyde was the worst trigger and two others, but not everyone. Formaldehyde is in 'everything' it seems. On exposure, tisseu gets inflammed and if one desn't get away form it then its like any 'wound' that just gets worse and worse until treated and avoidance is the 'cure' until the next exposure. I use Intal and maxiair canister in an older regular inhaler as my rescue inhaler. I'm just not able to 'suck in' without severe pain using the maxair autoinhaler. And my doctors have PFC studies showing this. Linda Joy Adams

I had developed asthma, but had not had an attack in several years until I started teaching in a school that was old and had many classrooms that had leaks, roaches and others allergens. My allergies and asthma got worse and worse over the years I taught there. finally, my last year teaching there, or anywhere, I was forced to teach in the most nasty, moldy old trailer you can imagine. It didn't matter how many cans of Lysol I used it was still awful. In addition to the asthma I developed chronic Migraines, Trigeminal Neuralgia and several other medical problems. I had to retire on disability retirement. We had so many students who had asthma too. Some rooms had carpet that was 40 years old. Schools are the nastiest places anywhere!