Stand by duty limitations

[lalbak]

Hello,

Is anybody aware of any rules regarding how far past the end of the standby period I am allowed to work if I get called up for a flight?

example: standby duty ends at 12:00 utc, get called up to start work at 11:00 utc but work a 7 hour duty, thereby being done at 18:00 utc, 6 hours past 12:00 utc. Is this possible?

Can't find any solid stuff on this.

thanks