Medical gas categories and definitions

NFPA 99-2018 – 4.1 Risk Categories

4.1 Risk Categories. Activities, systems, or equipment, shall be designed to meet Category 1 through Category 4 requirements, as detailed in this code.

• 4.1.1 Category 1. Activities, systems, or equipment, whose failure is likely to cause major injury or death of patients, staff, or visitors, shall be designed to meet Category 1 requirements, as detailed in this code.
• 4.1.2 Category 2. Activities, systems, or equipment, whose failure is likely to cause minor injury of patients, staff, or visitors, shall be designed to meet Category 2 requirements, as detailed in this code.
• 4.1.3 Category 3. Activities, systems, or equipment, whose failure is not likely to cause injury to patients, staff, or visitors, but can cause discomfort, shall be designed to meet Category 3 requirements, as detailed in this code.
• 4.1.4 Category 4. Activities, systems, or equipment, whose failure would have no impact on patient care, shall be designed to meet Category 4 requirements, as detailed in this code.

The category definitions apply to equipment operations and are not intended to consider intervention by caregivers or others. View examples of area/systems and their categories of risk below. A risk assessment should be conducted to evaluate the risk to the patients, staff, and visitors.

Note: Per NFPA 99 definition, Patient Medical Gases include: Oxygen, Nitrous Oxide, Helium, Carbon Dioxide, and Medical Air that are used in the application of human respiration and the calibration of medical devices used for human respiration.