Generally speaking, it is standard for agencies not to pay for the first 45 minute break, although it can vary regionally.
The main thinking behind it seems to be that if drivers are not being paid for their breaks, then they will not skimp on the break and drop the employers in the mire. - If your not being paid for it, then you may as well take it.
The main exception is ADR work, where the driver has to take their break whilst still being responsible for the safety of the load.