From an FAA point of view, a non-IR pilot should not be flying with a hood on, unless accompanied by an instructor. Under these circumstances, the pilot in command is the instructor.
As far as the FARs go [no pun intended
], as long as you're rated on type, eg. you're flying a SE aircraft and you hold a SEP rating but under the hood, then you are also entitled to log PIC. The Safety Pilot must be qualified and current on type, and ready to take the controls. Obviously a non IR'd SP cannot allow the flight to enter IMC but as long as the flight remains in VMC then everything is perfectly legal, and both Sole manipulator of the controls and Safety Pilot can log PIC.
Cheers
EA