What method is required to identify hazardous storage areas on life safety floor plans?

Any examples are for illustrative purposes only.

Portions of buildings that are considered hazardous by the definition of NFPA 101 (2012 edition) Life Safety Code, shall be identified on the life safety drawings per the requirements of LS.01.01.01 EP3.  There is no specific required method of identification.  Some organizations identify them with a symbol, some use a hatch overlay.  The method used should be shown on the drawing legend as identifying hazardous areas.

Even though many hazardous areas are required by code to have either 1-hr rated or smoke partition walls, it is not enough to simply have the walls of the hazardous area shown with the rating, as walls are often rated for other reasons.

The life safety drawings should also indicate whether the area is sprinkled and whether it is considered new or existing.  Facilities are classified as "existing" if final plans for construction, additions, renovations, or changes in occupancy were approved by the local authority having jurisdiction before July 5, 2016.  

Hazardous areas in health care occupancies are defined in Section 18.3.2 for new and 19.3.2 for existing.  Hazardous areas in ambulatory health care occupancies are defined in Section 20.3.2 for new and 21.3.2 for existing and refer to 38/39.3.2 (business occupancy) for requirements.