Yes. If you're using a circular saw for its intended purposes, the sound levels are considered to be within the acceptable daily exposure levels set by OSHA.  This is why it's important to wear earmuffs when cutting metal with this tool; these materials reflect sound energy and can cause more damage than wood at similar noise levels. But as long as you limit your exposure time (ideally don't use a circular saw if anyone else is nearby), there should be minimal risk of damaging your hearing.