R308.4.1

Section R308.4.1 is titled 'Glazing in doors' and covers the requirements for designating doors with glazing as a hazardous location. The types of doors to be considered as a hazardous location is established. The purpose of this section is to prevent severe injury from impact with glazing in doors. This section has 2 exceptions which allow for certain size and type of glazing to not be considered a hazardous location. The purpose of these exceptions is to allow for glazing, with a lower risk of severe injury in the event of impact, from needing to be manufactured and tested in accordance with safety standards.

The model shows 4 doors - 2 are required to be considered a hazardous location and the other 2 are not because they have features which are exempted, namely a 3" sphere won't pass through one and the other is made with decorative glass.