What is the difference between flammable and combustible?
Flammable goods can catch fire and burn easily at normal temperatures, whereas combustible goods require higher than normal temperature to ignite. In a grocery warehouse, it is essential to separate these goods into compartments to prevent fire hazards.
Dust Explosions
Dust explosions in grocery warehouses are likely. A dust explosion occurs when a concentrated and confined dust cloud comes in contact with an ignition source. This is an airborne risk and can be solved with thorough housekeeping and installation of a dust collection system in a warehouse.
The five cycles for dust explosions to occur are illustrated in this diagram. This diagram is also called ‘Dust explosion pentagon’.
- Fuel or combustible dust: This can be anything like sawdust, paper dust, flour or sugar (in case of a grocery warehouse)
- Oxygen: Atmospheric oxygen also works like a fuel or oxidant and if concentration of dust is very high, explosions might not occur if there is low oxygen to support combustion.
- Ignition: This is the source of fire.
- Dispersion: Distribution of the combustible dust.
- Confinement: The state of being confined or captive within an enclosure.
A strong pressure waveforms when combustible dust builds up and combusts in the right concentration level. Mainly three sources are required:
- Oxygen
- An ignition source
- An enclosed space- if the building is considered as an enclosure.
Initially a primary dust explosion occurs as a first point of explosion which gradually occurs to form a secondary explosion pressure when concentrated pressure builds up further resulting in a much more extensive explosion inside a warehouse.
Here is a list of common mundane organic goods which can disperse to form dust cloud in a grocery warehouse.
|
Name |
Details |
|
Flour |
If spilled into direct flame, flour can ignite. Flour ignition is common and a result of dust cloud caused Minnesota mill to explode in 1878. Flour is a carbohydrate and becomes more explosive when it gets mixed with the air. |
|
Grains |
Dust explosions are widespread in grain silos because of its ability to ignite. Grain dust is highly combustible and can be a hazardous if ignition source such as overheated motor, misaligned conveyor belt are nearby. |
|
Corn starch |
Another risky source of dust cloud within a grocery warehouse due to having a very fine particle. |
|
Sugar |
Sugar is also a carbohydrate like flour, and so it is flammable for the same reasons. When sugar gets hot enough, it can ignite and catch fire. |
|
Powdered milk |
Highly flammable when dispersed in a confined environment. |
|
Coffee creamer |
Contains sodium aluminosilicate, a substance that prevents coffee creamer from caking is flammable when dispersed. |
|
Coffee granules |
Flammable only when dry and comes in contact with an ignition source. |
The previous list consisted of both flammable as well as grocery goods that can cause explosions from dust cloud. The list below is contains both combustible and flammable good that do not form dust clouds but are still hazardous and require compartmentation when stored in a warehouse which stores household goods along with grocery.
|
Name |
Details |
|
Cooking oil |
Cooking oils are highly flammable and different oils vary on their smoke and flash points. A flashpoint is a temperature when oil creates flammable vapors which when exposed to heat can cause a fire. The table below shows the smoke points of different oils. |
|
All alcohol-based cooking sauces |
Cooking sauces are flammable because they contain small amounts of alcohol which might have flammable vapors. Open sauce bottles should never be left near heat sources as there is a risk of explosion from such sauce bottles. |
|
Cinnamon powder |
Contains cinnamaldehyde and eugenol, which are flammable. Much like flour, cinnamon can cause an explosion if it comes in contact with air. |
|
Aerosol cans |
Flammable propellants, such as propane or butane are used in many aerosol cans. In addition, the pressurized cans themselves are hazardous and risk of explosion is evident if overheated. An explosion also could occur if a pressurized can is accidentally pierced. |
|
Hand sanitizer |
Due to the presence of alcohol, common sanitizers can cause 2nd and 3rd degree burns if they are around an open flame. |
|
Oranges |
Orange produces limonene. The juice contained within the fruit allows an open flame to ignite very quickly and cause severe damage to a home or building. |
|
Nail polish and nail polish remover |
Contains acetone whose vapors are flammable and they are able to travel through the air, igniting any nearby flames. |
|
Paraffin-Based Skin Creams |
Many people used paraffin-based skin products which have soaked into their clothing and then ignited causing burns. |
|
Laundry Products
|
Almost all laundry products, stain removers and fabric softeners are flammable. So it is important to store them safely, and avoid exposure to a flame. |
|
Insect killers |
They contain harmful chemicals like Cyfluthrin, Permethrin, Pyrethroids |
Information source: StrikeFirstUSA, Robovent