Nowadays, modern world technologies are rapidly becoming part of the Internet of things (IoT) and 5G networks where the role of power line communication (PLC) technology will be predominant in some of the standard applications of IoT such as smart homes, smart industries, and smart grids by considering its favorable conditions. In this paper, we analyze the physical layer security (PLS) of a low-frequency PLC system in terms of average secrecy capacity (ASC), secure outage probability (SOP), and strictly positive secrecy capacity (SPSC) where the wiretap channel model is employed to measure the degree of data confidentiality between authorized and unauthorized user over low frequency PLC networks. The PLC channel characteristics are characterized by specifically, two different cases, when the main and wiretap channel are independent log- normally distributed and correlated log-normally distributed; concurrently the effect of impulsive noise is modeled by the Bernoulli Gaussian process. Furthermore, the impact of impulsive noise, the distance between the users, path loss factor, and transmitted power is also considered. The validity of the derived analytical results is established through close matching with the Monte Carlo based simulation results. © 2019 IEEE.