What Is NFPA 855 and Why Are Hospitals Now Required to Comply?

Battery backup systems and energy storage are no longer rare in hospitals. Between UPS systems for critical medical equipment, large-scale battery installations for grid resilience, and the growing adoption of on-site energy storage for backup power, many hospitals now have significant lithium-ion battery capacity on their premises — often without fully understanding that these systems fall under NFPA 855 and require inspection and documentation.

NFPA 855 — the Standard for the Installation of Stationary Energy Storage Systems — is the code that governs how these systems are installed, maintained, and inspected. For hospitals, compliance isn't optional once the thresholds are exceeded. Here's what facility managers and fire inspection contractors need to understand.

What Is NFPA 855?

NFPA 855 was first published in 2020 and most recently updated in 2026. It establishes minimum requirements for stationary energy storage systems — any system that stores electrical energy for later use. The standard covers everything from small residential battery systems to large-scale commercial and utility installations.

For hospitals, the most relevant systems include:

• Uninterruptible Power Supply (UPS) systems — battery backup for critical equipment including imaging systems, ICU monitoring, operating room equipment, and server infrastructure
• Large-scale battery energy storage systems (BESS) — increasingly installed for grid resilience, peak demand management, and backup power
• Emergency power systems with battery components — some modern emergency power systems incorporate battery storage alongside or instead of traditional generators

When Does NFPA 855 Apply?

NFPA 855 applies when the aggregate stored energy capacity in a fire area exceeds the threshold quantities in Table 1.3 of the standard. For the most common battery technology in hospitals — lithium-ion — the threshold is low:

A single large UPS system for a hospital server room or imaging suite can easily exceed 20 kWh of lithium-ion capacity. A hospital with multiple UPS installations across different departments may be significantly above the threshold without anyone having tracked the aggregate capacity.

What NFPA 855 Requires

Once the threshold is exceeded, NFPA 855 imposes requirements across installation, safety systems, and ongoing maintenance. For existing hospitals, the most relevant ongoing requirements are:

Operation and maintenance documentation

The system must be operated and maintained in accordance with the manufacturer's instructions and O&M documentation. That documentation must be present on site, accessible to the AHJ, and include procedures for startup, shutdown, inspection, testing of alarms and controls, and maintenance of fire protection equipment and ventilation systems.

Safety Data Sheets

SDS for hazardous materials in the ESS must be posted within sight of the disconnecting means — or at an AHJ-approved location. For outdoor systems, the SDS must be protected from weather.

Fire detection and suppression

Rooms containing ESS must be provided with smoke detection, thermal image fire detection, or radiant-energy-sensing systems per NFPA 72. Fire control and suppression systems are required in most configurations. These systems must be inspected and tested — typically triggering NFPA 72 and NFPA 25 inspection requirements in addition to 855.

Ventilation

Where required, exhaust ventilation systems must be operational and — where mechanical exhaust is used — supervised by a central/remote station or providing an audible/visual signal at an attended location.

Fire barriers

ESS rooms must be separated from other building areas by fire barriers with a minimum 2-hour fire resistance rating. ESS groups must be separated from each other and from walls by a minimum 3 feet.

Maintenance records

All maintenance must be performed by qualified individuals, with records documenting the action taken, the date, who performed it, and the results. These records must be accessible to the AHJ.

Why This Is Emerging Now

NFPA 855 was first adopted in 2020 — relatively recently in code adoption terms. Many jurisdictions are still in the process of adopting the standard, and many hospitals installed their battery systems before the standard existed or before local adoption. The 2026 edition is the most comprehensive version yet and is being adopted by an increasing number of AHJs.

As hospitals continue expanding their battery storage capacity — driven by energy resilience concerns, grid instability, and the increasing density of battery-powered medical equipment — the likelihood that any given hospital exceeds the 20 kWh lithium-ion threshold is growing rapidly.

What an NFPA 855 Inspection Looks Like

Unlike NFPA 25 or NFPA 72, NFPA 855 inspection frequency is not prescribed in the standard — it defers to the manufacturer's O&M documentation. The inspector's role is primarily to verify that required documentation exists and is current, and to conduct a physical condition inspection of the safety-critical components: detection systems, suppression systems, ventilation, fire barriers, and physical condition of the ESS enclosures.

The inspection produces documentation that the AHJ can review to confirm ongoing compliance — not just at installation, but throughout the system's operational life.