A final note
Protecting yourself in the workplace or at home is a serious matter. Not only are their OSHA laws that regulate the safety of the workplace it is just common sence that what you do today may have a serious outcome in a few hours, days, months or years.
Paints and pesticides have been known to kill people even when they think they are taking precautions to wear masks but you need to use the proper mask for the job and then you need to maintain that mask.
I actually have a friend that I worked with early on and he was painting clear coat on a car. He was using a Cartridge Mask System that should have been able to protect him for the hour or so while he was painting. However he did not change his filters and then he had an allergic reaction to the paint. He was rushed to the hospital and put on Oxygen for a few hours then released but after that he did not return to work.
Every person can react differently and when I talk with people that have worked in the industry for some time they say that over time their sensitivity to chemicals gets worse.
In-line respirators are definitely a choice you should make if what you are doing is more then a hobby. But you should never rely on any product unless you have read and understand its features and limitations. Going overboard is always suggested.