The SEMI S2 standard is a set of guidelines developed by SEMI (Semiconductor Equipment and Materials International). SEMI is an industry association for the semiconductor and related industries. SEMI S2 outlines the safety and health of requirements for semiconductor manufacturing equipment, including equipment used for photovoltaic cell manufacturing.

The SEMI S2 standard covers a wide range of topics related to equipment safety, including electrical and mechanical, radiation, and chemical hazards. The standard also addresses topics such as equipment installation, operation, and maintenance. In some cases additional standards must be used to supplement and cover some requirements more in depth, which is particularly true for electrical safety. Specifically for the electrical safety, SEMI has developed SEMI S22. Which covers in depth electrical safety requirements, including topics such as grounding and bonding, isolation and insulation, and protective devices. However, since majority of countries have regulatory requirements regarding electrical safety, some manufacturers use local standards and installation codes as guideline for electrical safety. For example EN 60204 for installations in European Union, or NFPA 79 for installations in the USA.   

It is important to note that compliance with the SEMI S2 standard is not mandatory by law. However, many semiconductor manufacturers adapted this standard as a base guideline to ensure the safety of their personnel and equipment.