I have been told by the PICC nurses, no lifting over 5 lbs with that arm. I went a month without working when i had my 1st PICC placed a few years ago. It was very very straining financially. So, early this year when we were discussing a 2nd PICC, I refused it and had worked out with my CF doc to have my coworkers (I'm a paramedic) place peripheral lines every 3 days so I could continue to work. After some research on the CF team's part, they found no policy of restricted weight lifting in the affected arm. They cleared me to continue working with my PICC in place and I never had a problem with it.
For most of us I think taking a few weeks to a month off work is just out of the question. It is for me anyway.