How hard to breathe in a full face respirator?

Yes.

 

In my experience the only time I have had to suit up was on Nalco loads which are always a driver unload.

To the OP, the full chemical suit is a special kind of hell in the summer. It can be brutal.

 

You were taking a 'baseline' lung function test to establish the level of your lung capacity. Any sudden decline in future capacity is a sign that he respirator was not effective. Prior to this you could be fit tested and allowed to work for years w/ out knowing if it was really doing harm.

As a driver you are exposed less than a plant worker. the TLV [threshold limit value] testing that requires the PPE is designed to protect 8 hrs. a day/ 40 hrs. a week so the hour or so you use it once a week means a lot less exposure compared to the level of protection the EPA requires for a full time worker. Don't let this scare you off. PPE is for your protection and I never visited any one in a hospital that USED all of their PPE...chew on that a while!