At what point is our participation in work sinful? The majority of our work place do not function on catholic principle. Therefore, at what point would your participation in work be sinful? Working at planned parenthood is probably sinful because they do abortions but is working for a company that supports abortion?
I would say that if you are performing a job whose function is to commit evil, then yes that would be sinful. For example, working to help planned parenthood or driving a truck for drug cartels would be wrong.
If you are performing work for a company that incidentally supports evil activity, then you would not be culpable. For instance, working for a soda company in order to make drinks is the primary purpose and extent of your work–even if the corporate officials decide to invest some of the finances into planned parenthood. It all goes back to the principal of double effect.