http://www.fairfaxcounty.gov/dfs/childrenyouth/supervision_eng.htm
The following represent minimally acceptable standards for the supervision of children. These guidelines have been developed by social work professionals in collaboration with the community. REMEMBER, they are guidelines only.
There may be situations, even within these guidelines, when it is not safe to leave a child unsupervised. Parents are ultimately responsible for making decisions about their child’s safety.