National Fire Protection 30 is the industry standard for the handling and storing of flammable and combustible liquids. While this standard is not enforceable under the NFPA, OSHA references and cites NFPA 30 in establishing its hazardous materials regulations. Manufacturers should reference NFPA 30 when handling and storing dangerous chemicals in conjunction with OSHA regulations. NFPA 30 includes a system of classifying and categorizing flammable liquids based on their physical properties and propensities to cause harm and environmental contamination.
What Are Flammable Liquids?
Although all hazardous materials can be destructive or toxic in small quantities, special consideration is given to the volatility of flammable liquids. OSHA defines a flammable liquid as any substances that has a low a flash point and requires compartmentalized storage away from incompatible materials. Gasoline, paint thinner, ethanol, and other common lubricants, degreasers, and fuels are considered flammable liquids. OSHA divides flammable liquids into four categories. Below is the NFPA 30 classification list for flammable and combustible liquids:
Class I Liquids: Flammable liquids that have a flash point below 100°F (37.8°C). They are further divided into three categories based on their volatility:
Class IA: Liquids with a flash point below 73°F (22.8°C) and a boiling point below 100°F (37.8°C).
Class IB: Liquids with a flash point below 73°F (22.8°C) and a boiling point at or above 100°F (37.8°C).
Class IC: Liquids with a flash point at or above 73°F (22.8°C) and below 100°F (37.8°C).
Class II Liquids: Combustible liquids with a flash point at or above 100°F (37.8°C) and below 140°F (60°C). They are also divided into three categories based on their flash points.
Class IIIA Liquids: Combustible liquids with a flash point at or above 140°F (60°C) and below 200°F (93.4°C).
Class IIIB Liquids: Combustible liquids with a flash point at or above 200°F (93.4°C).
What Are Some Common Examples of Flammable Liquids?
While the complete list of flammable and combustible liquids is extensive, we’ve included some of the more common industrial chemicals requiring compliant protection:
Gasoline
Diethyl Ether
Gasoline
Acetone
Toluene
Kerosene
Diesel
Benzene
Methanol
Hydraulic fluids
Oil
Turpentine
What’s The Maximum Storage Limit for Flammable Liquids?
Any flammable stockpile fewer than 25 gallons is above the purview with OSHA – you don’t need separate compartmentalized storage. But the requirements differ with larger volumes of flammable liquids. Any chemical stockpile greater than 25 gallons needs to be stored in an approved warehouse or container. OSHA requires that no more than 60 gallons of flammable materials with a flashpoint at or below 140 can be stored in an approved hazmat warehouse. Furthermore, OSHA requires no more than 120 gallons of combustibles with a flashpoint at or above 140 degrees can be stored in a single hazmat warehouse.
While OSHA provides general guidelines for flammable liquids storage, NFPA 30 establishes additional protocols for each classification subdivision. NFPA 30 18.5.4.1 stipulates the maximum quantity of flammable liquids in a single fire area should not exceed 25 gallons of Class IA liquids in approved containers. Additionally, NFPA 30 warns against storing more 120 gallons of Class IB, Class IC, Class II, or Class III liquids in containers. Finally, the NFPA caps any combination of Class IB, IC, or IIIA liquids in metal tanks or metal IBC containers – each not exceeding 793 gallons – at 1,585 total liquid gallons.
NFPA 30 Chapter 9.5
While the NFPA 30 safety requirements can be encumbering to daily operations, strict adherence to these standards is critical. NFPA 30 also outlines chemical storage cabinet guidelines, stipulating all Category I, II, or III flammable liquids should be kept in closed containers when not in use.
Storage Safety Cabinet Design
Storage cabinets designed and constructed to limit the internal temperature at the center of the cabinet and 1 in. (25 mm) from the top of the cabinet to not more than 325°F (163°C), when subjected to a 10-minute fire test that simulates the fire exposure of the standard time–temperature curve specified in ASTM E 119, Standard Test Methods for Fire Tests of Building Construction and Materials, shall be acceptable. Source: NFPA 30 9.5.
Hazmat Tote Storage
Although NFPA 30 Chapter 9.5 allows for the construction of wooden storage cabinets, we highly recommend a steel chemical storage locker or warehouse. NFPA 30 Section 9.5 for metal safety cabinets requires the “bottom, top, door, and sides of the (storage) cabinet shall be at least No. 18 gauge sheet steel and shall be double-walled.” Moreover, OSHA has stipulations for material strength. Per governmental regulation, all chemical storage lockers should be made up 18 gauge steel sheet protection from top to bottom. Furthermore, all hazmat lockers should have a three-latch door arrangement. All joints should also be riveted, welded, or made tight. Furthermore, the NFPA also says the door sill of the container should be raised at least two inches above the bottom of the cabinet to retain spilled liquid inside the storage locker.
Chemical Storage Locker Warning Signs
NFPA 30 also makes special mention of proper signage to alert workers of hazardous materials nearby. Each chemical storage cabinet or warehouse should display “FLAMMABLE” and “KEEP FIRE AWAY” signage and markings. The letter height for “FLAMMABLE” should be two inches while the minimum letter height for “KEEP FIRE AWAY” should be one inch. Furthermore, all letters should be uppercase and in contrasting color to the background. Additionally, the lettering should be placed on the upper part of the locker’s front doors or frame.
Ventilation
Although Section 9.5 of NFPA 30 doesn’t require ventilation, the standard provides regulations for either scenario: ventilated and non-ventilated storage. If a storage cabinet is not ventilated, the storage locker’s vent openings must be sealed with the bungs supplied with the cabinet. However, ventilated cabinets should be “ducted directly to a safe location outdoors or to a treatment device designed to control volatile organic compounds (VOCs) and ignitable vapors.”
NFPA 30 Compliant Chemical Storage
While the scope of NFPA 30 standards can be difficult to comprehend, U.S. Hazmat Storage can guide compliant storage protection. Our fire-rated chemical storage lockers meet all NFPA 30 and OSHA standards and regulations. Unlike wooden cabinets, our chemical storage lockers provide optional mechanical ventilation, preventing the toxic buildup of vapors. Moreover, optional fire suppression and explosion relief panels give your stockpiles an additional level of protection. U.S. Hazmat Storage offers fire-rated chemical protection for various sized stockpiles. We can ensure continuous chemical storage protection for steel drums and larger IBC tote systems. Wide-swinging doors and pushed-back shelving allows for the easy retrieval and storage of hazardous chemicals by forklift. Contact us today for a free quote and consultation.
How NFPA 30 Section 9.5 Is Enforced in Real-World Inspections
While NFPA 30 itself is not a legally enforceable code, its requirements are routinely applied during real-world inspections through OSHA, local fire marshals, and Authority Having Jurisdiction (AHJ) reviews. In practice, NFPA 30 Section 9.5 becomes enforceable when it is referenced by OSHA regulations, adopted by state or municipal fire codes, or incorporated into site-specific safety plans.
During inspections, regulators typically evaluate whether flammable liquid storage cabinets and lockers meet the construction, labeling, containment, and placement requirements outlined in Section 9.5. Inspectors often verify cabinet materials, gauge thickness, door design, spill containment features, signage visibility, and container compatibility. Failure to align with these requirements can result in citations, operational shutdowns, or mandated corrective actions.
For industrial facilities, manufacturers, and government sites, proactive compliance with NFPA 30 Section 9.5 reduces inspection risk, improves audit outcomes, and demonstrates a documented commitment to chemical safety and hazard mitigation.
Best Practices for Maintaining Ongoing NFPA 30 Section 9.5 Compliance
Achieving compliance with NFPA 30 Section 9.5 is not a one-time task-it requires ongoing evaluation and maintenance. Facilities storing flammable or combustible liquids should implement routine inspections of storage cabinets, lockers, and warehouses to ensure structural integrity, proper labeling, and unobstructed access.
Best practices include maintaining an up-to-date chemical inventory, verifying container compatibility, and ensuring storage quantities remain within permitted limits for each liquid classification. Any cabinet ventilation systems should be regularly inspected for proper ducting and vapor control, while non-ventilated cabinets must remain securely sealed to prevent vapor leakage.
Training personnel on flammable liquid handling, spill response, and cabinet usage further strengthens compliance. When storage needs expand or chemical volumes increase, facilities should reassess whether existing storage solutions still meet NFPA 30 Section 9.5 requirements or if a fire-rated chemical storage locker or warehouse is necessary.
Consistent adherence to these practices not only supports regulatory compliance but also significantly reduces fire risk, environmental exposure, and workplace hazards.
Frequently Asked Questions (FAQs)
Is NFPA 30 Section 9.5 legally enforceable?
NFPA 30 itself is not a federal law, but Section 9.5 becomes enforceable when it is referenced by OSHA regulations, adopted by local fire codes, or enforced by an Authority Having Jurisdiction (AHJ). In many inspections, compliance with NFPA 30 Section 9.5 is treated as a mandatory safety requirement.
What types of storage cabinets are allowed under NFPA 30 Section 9.5?
NFPA 30 Section 9.5 permits both metal and wooden safety cabinets if they meet fire-resistance testing and construction standards. However, metal safety cabinets constructed from at least 18-gauge steel and designed with spill containment features are most commonly accepted during inspections.
Does NFPA 30 Section 9.5 require ventilation for flammable liquid storage cabinets?
Ventilation is not mandatory under Section 9.5. Cabinets may be either ventilated or non-ventilated. If ventilation is used, it must be ducted to a safe outdoor location or approved vapor control system. Non-ventilated cabinets must have sealed vent openings using the manufacturer’s supplied bungs.
How much flammable liquid can be stored in a single NFPA 30 compliant cabinet?
NFPA 30 Section 9.5 limits storage quantities based on liquid classification. In general, no more than 25 gallons of Class IA liquids or 120 gallons of Class IB, IC, Class II, or Class III liquids may be stored in approved containers within a single fire area, unless otherwise permitted by code.
Are warning labels required on NFPA 30 Section 9.5 storage cabinets?
Yes. Storage cabinets must be clearly marked with “FLAMMABLE” and “KEEP FIRE AWAY” signage. The lettering must be uppercase, in contrasting colors, and positioned on the upper portion of the cabinet doors or frame to ensure visibility during inspections.
How often should flammable liquid storage be inspected for compliance?
Best practice is to conduct routine inspections at least quarterly, or more frequently in high-use environments. Inspections should verify cabinet integrity, door latching, spill containment, labeling, container condition, and adherence to storage quantity limits outlined in NFPA 30 Section 9.5.
When should a facility upgrade to a fire-rated chemical storage locker?
Facilities should consider upgrading when flammable liquid volumes exceed cabinet limits, when IBC totes or drums are introduced, or when inspections identify compliance gaps. Fire-rated chemical storage lockers provide enhanced protection and simplify compliance for larger chemical inventories.
