The OP states "My new job only allows BlackBerry devices for security reasons"
Now, does this mean that the Blackberry is a prerequisite of his job? If the answer is "Yes", then, the employer should supply him with a Blackberry. If the answer is "No", the employer is, in effect, stating that if employees want to take a mobile 'phone into work, for security reasons, it has to be a Blackberry.
In the latter case, the OP has two alternatives, (!) Buy a Blackberry to take into work. (2) Leave his iPhone at home and go to work sans mobile.
Simple as that. 🙂