Paint, solvents, oils, alcohols, adhesives and cleaning chemicals: in many warehouses ignitable liquids sit in drums, jerry cans, IBCs and small packages right next to ordinary commodities. When these containers fail in a fire, the fire does not stay in the rack; it spreads across the floor, runs into drainage channels and extends well beyond the area the sprinkler design assumed. FM Global DS 7-29 Ignitable Liquid Storage in Portable Containers deals with this risk from container type and storage arrangement through to drainage and sprinkler design.
Scope and the "Ignitable Liquid" Concept
The data sheet covers ignitable liquids stored in portable containers: small cans and bottles, metal and plastic jerry cans, drums, metal and composite intermediate bulk containers (IBCs) and safety cabinets. Fixed tanks and process equipment are covered elsewhere (process areas by DS 7-32). Instead of the flammable/combustible split, FM uses the term ignitable liquid: any liquid or liquid mixture that can burn is in scope. That brings in liquids classed as "non-flammable" because of a high flash point but which will heat up and burn in a fire.
Factors That Set the Hazard
| Factor | Why it matters |
|---|---|
| Flash point and boiling point | Ease of ignition and vapour production |
| Container material (metal/plastic/glass) | Plastic and glass fail quickly in a fire and release their contents |
| Relieving or non-relieving metal container | Non-relieving containers can rupture when heated and project liquid |
| Container size | Larger containers mean larger spills and pool fires |
| Water miscibility and viscosity | Affect foam selection and spread rate |
| Storage arrangement and height | Palletised, solid pile or rack, together with ceiling height, drive the sprinkler design |
Key Loss-Prevention Principles
1. Limit the spill fire: containment and drainage
At the heart of the FM approach is controlling where the liquid goes. Sprinklers can control burning containers in a rack, but burning liquid spreading across the floor becomes a pool fire larger than the sprinkler design area. Sills, ramps, curbs and floor slopes keep the liquid within a defined area, while emergency drainage carries burning liquid and firewater to a safe collection point. Drainage must also be sized for sprinkler and hose water.
2. Segregation and quantity limits
Significant quantities of ignitable liquid belong not in the general warehouse but in a cutoff room with fire-resistant walls, a detached building or an outdoor storage area. The quantities allowed in general storage areas are limited, and the limits vary with liquid class and container type. Small quantities can be kept in approved safety cabinets.
3. Container selection
Choosing the container is a fire protection decision. Relieving-style metal containers vent vapour in a controlled way rather than rupturing, which helps sprinklers control the fire. Plastic containers and standard plastic IBCs melt quickly and create a large spill fire. FM treats fire-tested approved composite IBCs (under FM Approval Standard 6020) separately; they perform markedly better than unapproved plastic IBCs.
4. Sprinkler and foam-water protection
Sprinkler design is selected from the data sheet tables by liquid class, container type, storage arrangement, and storage and ceiling height. Some arrangements need in-rack sprinklers, some need foam-water. Using "the nearest row" for a combination outside the tables is wrong; a design not backed by fire testing may not work in a real fire. Use the current revision for design values.
5. Ignition sources and operations
Dispensing and transfer should not take place in the storage area; those are process operations covered by DS 7-32. Electrical equipment is selected for the liquid class and hazardous area zoning, and the same assessment applies to forklifts. Damaged or leaking containers are moved to a separate area immediately.
How It Differs from NFPA 30 and European Practice
NFPA 30 classifies flammable and combustible liquids by flash point and boiling point (for example Class IA: flash point below 22.8 °C (73 °F) and boiling point below 37.8 °C (100 °F)) and gives protection tables for container storage. Through the ignitable liquid concept FM brings a wider range of liquids into scope and makes container behaviour (relieving or not, approved or not) a direct design input. There is no single EN sprinkler design standard for container storage of ignitable liquids in Europe; projects are usually designed to national rules, insurer criteria, VdS guidelines or NFPA 30. In Turkey, the flammable liquid provisions of the national fire regulation and explosive atmosphere legislation also apply.
Common mistake: placing "a few pallets of paint and solvent" in the racks of a standard ESFR warehouse as if they were ordinary goods. The ESFR design may not be valid for these liquids, and even a small-looking quantity can invalidate the protection assumption for the whole building.
Practical Checklist
- All ignitable liquids are inventoried with flash point and container type.
- Quantities in general storage are within the data sheet limits; the excess is in a cutoff room or separate building.
- Containment (sills, curbs, slopes) and emergency drainage capacity are calculated.
- Containers are relieving-style metal or approved composite IBCs wherever possible.
- Sprinkler and, where required, foam-water design rests on an exact combination in the data sheet tables.
- Transfer and dispensing take place outside the storage area.
- Electrical equipment and forklifts suit the hazardous area zoning.
- Small quantities are kept in approved safety cabinets.
- A quarantine area and spill kit exist for damaged containers.
Frequently Asked Questions
What is the difference between an ignitable and a flammable liquid?
The flammable/combustible split is based on flash point. FM's ignitable liquid term covers every liquid that can burn, including high flash point liquids that burn in a fire.
Can plastic IBCs be used?
Unapproved plastic IBCs melt quickly in a fire and create a large spill fire. FM views fire-tested approved composite IBCs more favourably; the protection design depends on the container type.
Does ESFR protect ignitable liquid storage?
Only where the data sheet tables provide for a specific liquid, container and arrangement. Applying a general-purpose ESFR design to ignitable liquids is not correct.
How much liquid does a safety cabinet make safe?
Approved safety cabinets protect small quantities during a short fire exposure. The quantity per cabinet and the number of cabinets in an area are limited; cabinets do not replace proper storage for larger stocks.
Why does drainage matter so much?
If burning liquid spreads across the floor, the fire exceeds the sprinkler design area. Drainage and containment keep the fire to a size the sprinklers can handle.
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Download SprinkCalc on the App StoreFM Global Property Loss Prevention Data Sheet 7-29, Ignitable Liquid Storage in Portable Containers; FM Approval Standard 6020; NFPA 30, Flammable and Combustible Liquids Code. This page is a summary in our own words, not the data sheet text. Download and design to the current revision from fmglobal.com.