Isocyanates are diferent from just plain paint and incredibly dangerous. Paint respirators are not sufficient to safeguard the user.
CDC - Isocyanates - NIOSH Workplace Safety and Health Topic
Isocyanates and Asthma < Painters and Repairers Education Program
I don't need an education on this, I have been using these products professionally for over 40 years.
Yes, isocyanates are dangerous. However, only a very small percentage of people are ever affected by them. The vast majority of people who use them in this country daily, DO NOT take the proper precautions, (trust me, I have seen it first hand, by others using them professionally). After many decades, there is no epidemic. Yes, some people do get sick. But, it's not a widespread problem. If there was, the lawyers would be all over it.
Realistically, you can't even take the lid off the can of hardener, or walk in to the area paint is being mixed, or painted parts are drying or resting, without being exposed to the isocyanates, as well as all the other chemicals in there. Yet, you can go in to any shop, or watch any video on using these products, and see people doing these tasks without any respiratory protection. They are all breathing this stuff in every day.
I believe in using the proper protection. And, though you seem to want to believe that the other ingredients are not as dangerous, THEY ARE. And, to some people they may be more dangerous. Many paint chemicals are known carcinogens. You can't know which chemical(s) are going to do you in. So, if you are smart, you protect yourself from ALL of them.
It is incorrect to say paint respirators are insufficient. They are made exactly for this purpose, and used properly, along with the correct other personal protective equipment, will protect you.
The ONLY problem with using a respirator here is, without testing, you can't know your exposure level. So, you can't know how long you can wear it before you have to replace the filters.
I have had many OSHA certification classes, and been OSHA exposure tested for isocyantes, as well as all the other chemicals in the paint. This DOES allow you to use a paint respirator for protection. Because, you can calculate the amount of exposure in PPM, per hour, and divide by the amount of PPM the respirator can trap. Using this formula, you can CONCLUSIVELY show that your employee is protected, that MEETS the OSHA requirements.
Spraying all day long, my exposure levels were well within what my respirator could protect me from for over 40 hours of use. And, you are never going to find yourselves using these products at the level I was, when the testing was done.
So, as I said, if you really want to overkill it, don't go past 20 hours of use, on a set of filters and you will be fine.
Fresh air systems can give you false security. Have you tested the air quality? If not, you have no idea what you are breathing. There could be among others, oil, and toxic chemicals that have been drawn into the pump, or is leeching out of the hoses. These systems also usually have filters that also need to be exposure tested to determine the change interval. Otherwise, they could eventually be putting contaminates into the air instead of taking them out.
I have used several types of respiratory protection. I do not like air supplied systems primarily because I do not like having a hose tugging on my belt. It gets hung up on things all the time when you are moving around. There is enough to worry about when you are doing this work, without adding to the list.
