Many times, the isolators are used in systems due to their intrinsic capability to block high-voltage common mode and their robustness to maintain signal integrity when subjected to high switching noises across the isolation barrier, and typically not for compliance with safety standards or certifications bodies that isolators are generally rated for.

For instance : Digital isolators are often times used inside Safety Extra Low Voltage (SELV) systems for blocking common mode of up to 60V. Within SELV systems, there is generally no safety requirement, like surge or lightning protection. Digital isolators in these designs are merely used for blocking high common mode and noise across the isolation barrier.

Such designs still make use basic or reinforced certified digital isolators in the non-safety stages, which might be an overkill.