The continuing changes in legislation concerning both the design and use of machinery and equipment require the isolation of almost any type of industrial system or interface. The inter-integrated circuit bus (I2C Bus) is a single-ended, multi-master, two-wire bus; and, while designed only for short-distance I2C communication, it is no exception to isolation requirements. This paper provides a short introduction to I2C Bus operation and then describes how to design an isolated I2C interface by adding only a few external components to a digital capacitive isolator.