Existing standards, especially UL1703 for the modules and UL1741 for the balance of system components, and codes, especially the National Electrical Code, are written to make PV installations safe.
Recently, safety experts have identified arc fault circuit interrupters as a new device that will improve the safety of PV installations. The 2011 National Electrical Code includes a requirement for arc fault circuit interrupters. UL is developing a (new or revised) standard, UL1699, so these new devices can be certified.
Learn more about Arc Fault Detection and Mitigation