Storage of Flammable Materials

Proper storage is essential to protect flammable materials from ignition sources. Through proper storage, fires can be prevented and better controlled (to minimise fire spread) should it occur.

This blog post focuses on fire safety measures for minor storage (involving a small cluster) of flammable materials.

As per Singapore Standard SS 532: 2007 Code of Practice for The Storage of Flammable Liquids, “minor storage” refers to the storage of flammable liquids, in various locations, in small  quantities no larger than the set quantities specified in the standard.

In general, minor storage refers to any storage of flammable liquid (i) less than or equal to 50 litres or 2.0 litres/m2, and 

(ii) not more than 200 litres per minor storage area. The criteria forclassification as minor storage, however, varies with the location of storage (e.g., in a residential building, in a commercial building, in a storage warehouse, in a laboratory, in a factory, etc) as well as the degree of flammability of the liquid being stored (e.g., extremely flammable versus highly flammable). Details of the classification criteria can be found in Table 2 of SS 532: 2007.

Note that storage of petroleum and flammable materials (P&FM) is regulated by SCDF and a P&FM storage licence may be required (depending on storage quantity) prior to bringing such materials onto your premises. More information on fire safety and P&FM licensing may be found on SCDF website (www.scdf.gov.sg).

Specific guidance on the storage of flammable gases can be found in NFPA 55: 2013 Compressed Gases and Cryogenic Fluids Code and NFPA 58: 2014 Liquefied Petroleum Gas Code. Suggested references for specific storage situations (namely, hazardous material warehouses, LPG cylinder installations and laboratories handling chemicals) are provided in the References section of this Guidelines.

Here are the recommended Practice for Minor Storage of Flammable Materials

•Keep the amount of flammable materials in storage as small as possible.

•Keep storage areas away from any heat and ignition source.

•Ensure that storage areas are well-ventilated so that flammable vapour concentrations (e.g., due to spillage or leaks) can be kept low (below the LFL).

•Store flammable materials in a cool (e.g., under a shelter or under temperature-controlled environments if necessary) and dry (to prevent metal container corrosion as well as workplace slips, trips and falls) location.

•Store flammable materials in areas accessible by emergency response teams. Ground floor storage is recommended as this will provide for easier access during an emergency.

•Store flammable materials separately, away from process and production areas and other combustible materials. This separation will reduce the spread of any fire originating from the flammables storage area. The separation will also protect the stored flammable material from exposure to fires in neighbouring areas, as well as accidental contact with incompatible materials (e.g., oxidizers).

•Store flammable liquids with flash points lower than room temperature under appropriate conditions (e.g., under refrigerated conditions). Do not store flammable liquids in a standard refrigerator meant for household use as they are not designed to be free of ignition sources. Store small quantities of flammables only in a laboratory-safe or explosion-proof refrigerator. The refrigerator’s temperature needs to be set lower than the flash point of the most readily ignitable substance stored in the refrigerator.

•Do not store flammable materials in areas that may jeopardise escape in the event of fire. In particular, make sure that storage containers do not block fire lifts, fire exits, stairwells and any aisles leading to exits.

•Store flammable materials in separate minor storage clusters separated by a suitable safety distance (see Table 16 for guidance on minimum separation distance) or fire-resistant walls.

•Store larger quantities in metal drums placed on spill control pallets or within a dike. Smaller quantities may be stored in a fire-rated (minimum 1 hour) storage cabinet designed to protect its contents from the heat and flames of an external fire.

•Do not use plastic or glass containers for storing flammable liquids unless storage in metal containers affects the purity of the liquid or if the liquid causes excessive corrosion of the metal container.

•Inspect all incoming containers to ensure that they are not damaged. Do not accept delivery of defective containers.

•Affix all flammable material storage containers with GHS labels and keep them closed when not in use.

•Practice good housekeeping and immediately clean up any spills that occur in the storage area.

•Allow only trained, authorised personnel into storage areas.

•Inspect storage areas regularly for any deficiencies such as damaged or leaking containers, poor ventilation or non-approved equipment. Correct all deficiencies as soon as possible.

•Provide storage areas with adequate firefighting and spill clean-up equipment.

Separation Distance for Minor Storage

The following guidance on minimum separation distance is based on Singapore Standard SS 532: 2007 Code of Practice for The Storage of Flammable Liquids: