IEC 60601-1 Edition 3.1 was introduced in 2012 to address many issues identified as unclear or ambiguous in the original 3rd edition standard that was released in 2005. Edition 3.1 includes almost 500 changes and clarifications across a spectrum of subjects, including essential performance, risk management, mechanical testing, temperature testing, and humidity testing. The amended standard also defines several new specifications for mechanical and electrical hazards.