48 volts is not considered dangerous unless some very special conditions exist, none of which you are likely to encounter.
You'd probably have to immerse yourself in salt water and attach special leads so the current flows through your heart...
My off grid system consists of a 48 volt (51 volt nominal) 25kWh lithium ion battery.. (see photo). There is no place in that cabinet that a human can touch that would harm them. I have trained my wife and 8 year old on how to start the system and, because all that shiny copper can be intimidating, had them touch all kinds of things while one hand was firmly grasping the negative terminal..
The only real hard rule is "No metal on your body".. No rings, no watches, new jewelry..
The human body, like all other things, has resistance that must be overcome in order for any appreciable current to flow. While there are some people who claim they can feel 48 volts from a battery, I think it is a rare phenomenon involving very few people with some kind of genetic abnormality. The other 99.99% of us has little to no chance of feeling a 48 volt circuit unless we are dripping in sweat (Salt water).. and even then, its only a slight tingle.