You can not "steer" but you can make them aware of what the area is like in terms such as appreciation rates, Curb appeal and pride of ownership characteristics, tenant vs owner occupancy rates, foreclosure rates/ frequency, and published criminal statistics, such as registered predators in some cases.
And as indicated above, you can always say that you do not personally feel comfortable in that area. You could arrange for another agent to accompany you or other things your broker could recommend. Your personal safety is most important.
I often ask the potential buyer if they are familiar with the area and if they would like to do a drive-by prior to making a showing appointment.
Rules against not steering clients does not mean you are required to place yourself in any danger or discomfort. They also do not forbid you from making your potential buyer fully aware of the material characteristic of the neighborhood, marketability of the property and potential for value changes and in which directions.
Above all your job is to inform your buyer as best you can... you are representing their interest.
Do realize that many investors will look at areas they personally would never wish to live... they are looking at investment potential. Know what your clients intent is and "log" out of the office with full information and have a call back program set up with your "safety" partner... if you don't have one or know what that is... your broker should.