Handling of Flammable Materials

Flammable materials present a fire hazard in any workplace as they are readily ignitable, easily causing a fire. Users of flammable materials are advised to consult this chapter prior to attempting any work involving a flammable material.

Recommended Practice for Safe Handling of Flammable Materials

•Consult the SDS for each material you work with, identify those that are flammable and understand their flammability characteristics. The other hazards of the material may need to be addressed such as health toxicity and reactivity, and general guidance can be found on the SDS.

•For each material identified as flammable, ensure that its container is correctly labelled (see the GHS labelling) to indicate the hazardous nature of its contents.

•Check each container to ensure that it is not damaged and that its safety features (e.g., relief vent, flame arrester, any spring-loaded mechanism) are in good condition and working properly.

•Obtain the completed risk assessment form for the work activity to be performed. Identify the existing risk controls already in place and the additional control measures that need to be taken to further bring down the risk level associated with the work activity.

•Practice good housekeeping and check that your work area is free from combustible materials.

•Familiarise with the fire emergency response plan for your specific work area.

•Inspect your work environment and confirm that there are no ignition sources (e.g., open flames, sparks, hot surfaces) in your work area.

•Put on the appropriate PPE (e.g., safety goggles, fire-retardant coveralls and gloves) prior to any work activity involving flammables. Be familiar with the correct PPE for day-to-day operations, as well as for emergencies.

•Work behind a splash guard or face shield when working with a machine or process that ejects flammable or combustible liquids.

•Use only the minimum amount of flammable material for your work. It is good practice to keep no more than a day’s supply of flammable material in your immediate work area. Return any leftover material to the proper storage area or cabinet at the end of each work day.

•Bond and ground metal containers before transferring flammable liquids (or powders). •Where practicable, carry out the transfer of flammable materials under local exhaust ventilation or via closed system transfer (e.g., through fixed piping systems) so as to avoid the creation of flammable vapour concentrations in the atmosphere. If this is not possible, ensure that the work environment is well-ventilated before dispensing or using a flammable material.

•When transferring a flammable material, work in an area where a fixed gas detector has been installed or use a portable gas detector to continuously monitor the work environment. Programme the detector to raise an alarm before dangerous concentrations are reached.

•Always keep containers of flammable material closed when not in use in order to minimise the escape of flammable vapours.

Bulk Handling of Flammable Materials

ISO tank containers (i.e., tank containers built to standards set by the International Organisation for Standardisation) are commonly used for the bulk transportation of chemicals (including flammable materials) within Singapore via the use of prime movers and trailers. ISO tank containers are made of stainless steel and come in a variety of sizes ranging from 27,000 to 40,000 litres

For transporting smaller bulk quantities of chemicals, Intermediate Bulk Containers (IBCs; size ranging from 1,000 to 1,250 litres per IBC) and cylindrical metal drums (200 litres per drum) are typically used.

Other types of containers used for carrying flammable materials include tube trailers (e.g., for transporting compressed hydrogen) and gas cylinders (e.g., for transporting liquefied petroleum gas).

For work involving bulk loading/ unloading of a flammable material, it is important to ensure that the following are made available on-site at the loading/ unloading facility prior to work commencement:

•automatic water sprinkler system

•fire extinguisher(s)

•emergency stop button

•eye wash and safety shower

•first aid box

•spill control kit

Loading/ Unloading of ISO Tank Containers

An ISO tank container can be loaded or unloaded from its top or bottom. On a standard tank container, there is a manhole and at least one valve at its top, and another at its bottom. Loading and unloading is achieved by connecting hoses from the loading/ unloading facility to the valves of the tank container. Loading or unloading is then carried out by gravity, pressurisation or pumping. 

For safe loading/ unloading of a flammable material to/ from a tank container, it is critical to prevent static build-up through electrical bonding and grounding. Grounding (earthing)connections are typically provided at the bottom front and rear of each ISO container to prevent differences in electrical potential arising between the tank container, the body of the vehicle, the piping used and the ground during the loading/ unloading operation.

Proper bonding and grounding (earthing) will prevent the formation of electrostatic sparks which can ignite the vapours of the material being transferred.

Further guidance on the safe handling of chemicals in logistics operations is available in SCIC’s Guidebook on Transport & Handling of Dangerous Goods.

Loading/ Unloading of Intermediate Bulk Containers and Pallets of Metal Drums

IBCs are reusable industrial containers designed for the transport and storage of bulk liquid and granulated materials. The most common IBC is the single-use plastic composite IBC – a white/ translucent cube-shaped plastic container (typically made of polyethylene) housed within a tubular galvanized iron cage. For flammable materials, the use of metal IBCs (fitted with a venting device) is recommended for enhanced fire resistance. IBCs are designed to be stackable and moved with a forklift or a pallet jack.

An alternative to the use of IBCs is the use of palletised metal drums (typically 4 to 6 drums per pallet). Each pallet of drums (also known as barrels; typically made of steel) is also stackable and can be moved with a forklift or a pallet jack.

When loading/ unloading an IBC or a pallet of drums from the back of a lorry/ truck or when moving it with a forklift within the work area, extra care must be taken not to puncture or drop the containers as this will cause a spill resulting in the formation of a flammable vapour cloud.

When filling an IBC or drum with a flammable liquid, proper bonding and grounding is again necessary to prevent the formation of electrostatic sparks during the transfer. Specially designed drum funnels, fitted with a flame arrester, may be used to affect the safe transfer of flammable liquids. A large diameter funnel will also help to minimise the risk of spills.