For businessespowered by theirequipment or theirfleet, engine oil is an essential productthatmaybe storedin bulkonsite.Whether you’ve got just a fewdrumsin your workshop or you’re carrying thousands oflitres, engineoilsmust be stored in a way thatreduces your risk.To ensure the safe storage ofmotoroil, you must firstunderstand thechemicalproperties of the substance. This bloghighlights thechemical properties ofengine oil and answers the commonly askedquestion, ‘Is oil flammable’. We’ll also give you tips on how to storeoilsafelyin both outdoor and indoor locations. Engine oilsare viscous petrochemicals that have been derived from the fractional distillation of crude oil.As you’re probably aware, oils are immiscible with water—which means that the two liquids won’t mix. Crude oil is formed deep underground from the decomposition of organic organisms such as algae. After millions of years of geological heat and pressure, the organic matter transforms into oil and gas. To determine if a substance is flammable, you must define theflash pointof the liquid. The flash point is thelowest temperaturethat the liquidreleasesenoughvapoursto ignite in the presence of an ignition source. Engine oils normally have a flashpoint greater than 150°C.This means that they’re not a Class 3 Flammable Liquid, as flammable liquids must have a flash pointbelow 60 °C.Therefore, engine oils are classed ascombustible liquids. For the purposes ofthe Australian StandardAS1940:2017, combustible liquids arethen further classed into 2 categories: Substances, such as engine oil,that have a flashpoint above 150 °C areclassified asC2combustibleliquids. When flammable liquids burn,it’snot the liquid that burns, but the flammablevapourthat is dispersed from the flammable liquid. The more easily a liquid gives of flammablevapours, the more easily it will ignite in the presence of an ignition source. Flammable liquids that give off a lot offlammable vapoursare those that are made up of relatively small molecules. Smaller molecules have weaker intermolecular forces of attraction between the molecules.These types of substances require less heat energy to break the bonds between the liquid molecules (causing them to escape as flammablevapour). Compared with flammable liquids, oilsare made up of heavier hydrocarbons that have around 18-34 carbon atoms per molecule.The intermolecular forces of attraction between the molecules are a lot stronger than the forces of attraction that would exist between the small molecules that make upliquids such aspetrol.What Is Engine Oil?
How Are Engine Oils Classed?
WhyAre Oils Less Volatile Than Flammable Liquids?
Oils are regarded as a less volatile substance than flammable liquids due to their flash point of150 °C, but they are still subject to safe storage requirements.
As the intermolecular forces of attraction are strongerinsubstancessuch asengine oil, theywill not burn at room temperatures.
AC2 combustiblesubstancewould have to be subject to temperatures greater than 150 °C for it to produce enough flammablevapoursto ignite in the presence of an ignition source.Therefore,due to these chemical properties,oils are less volatilesubstancesthan flammable liquids.
HowShouldYou Store EngineOil?
Even though engine oils are not classified asClass 3 Flammable Liquids, theyare still classed as Dangerous Goods. Therefore, engine oils must be stored in a safe,compliant manner. If engine oilsaresubject to higher temperatures, there is a possibility that they would produce enough flammablevapoursto ignite in the presence of an ignition source.
The Australian Standard that outlines the requirements for the storage and handling of combustible liquids isAS1940:2017- The storage and handling of flammable and combustible liquids.
ThisStandard outlines the design requirements foroutdoor and indoorcombustible liquid storage facilities—as well as the segregation and separation requirements for the positioning of combustible liquids stores.
Outdoor Storage Of Engine Oil
As engine oil is regarded as a combustible liquid, it must be stored as per the requirements of the AS 1940:2017.
The design requirements foroutdoor combustible liquids storesincludes factors such as:
- Ventilation
- Spill containment
- Dangerous Goods Signage
Ventilation
To keep the concentration of combustiblevapourswithin the store below the workplace exposure standard, combustible liquids storage facilities must have sufficient ventilation— whether it’s natural ventilation or mechanical ventilation.
Mechanical ventilation systems installed on combustible liquids storage facilities must be intrinsically safe. Therefore,natural ventilation systems areamore practicalsolutionand the preferredventilationoption.
A compliant natural ventilation system can be achieved by having two walls of a combustible liquids store open to the outside atmosphere. These openings on the store can be cladded with a wall of fixed louvers.
SpillContainment
To ensure that any potential spills within the combustible liquids storage container are contained in a safe and compliant manner, all combustible liquids storage facilities must have a spill containment sump in the base of the storage facility.
The capacity of the spill containment sump depends on the quantity of oils being stored within the unit. The required spill containment capacities according to AS1940 are shown below:
FacilitiesStoring Less Than 10,000L
Spill containment capacity = 100% of the largest package within the store + 25% of the aggregate capacity of the store.
FacilitiesStoring Between 10,000L- 100,000L
Spill containment capacity = 100% or the largest package within the store + 25% of the aggregate capacity of the store + 10% of storage capacity between 10,000L and 100,000L.
FacilitiesStoring More Than 100,000L
Spill containment capacity = 100% of the largest package within the store + 25% of the aggregate capacity of the store + 10% of storage capacity between 10,000L and 100,000L + 5% of the storage capacity exceeding 100,000L
SegregationRequirements For Combustible Liquids Storage Facilities
Flammable and combustible liquids areincompatiblewithsomeother classes ofDangerous Goods.
If incompatibleDangerous Goodsmix,it can result in violent chemical reactions that could harm people and property. To reduce the risk of chemical reactions, flammable and combustible liquids must be segregated from other incompatible classes ofDangerous Goods.
The compatibility of flammable/combustible liquids with other classes ofDangerous Goodsis shown on the chart below:
Dangerous Goods class | Segregation required from Class 3 Liquids |
Class 2.1 - Flammable Gas | Segregate |
Class 2.2 - Non-flammable, Non-toxic Gas | Keep Apart |
Class 3 - Flammable/Combustible Liquids | Compatible |
Class 4.1 - Flammable Solids | Keep Apart |
Class 4.2 - Spontaneously Combustibles | Segregate |
Class 4.3 - Dangerous When Wet | Segregate |
Class 5.1 -OxidisingAgents | Segregate |
Class 5.2 - Organic Peroxides | Isolate |
Class 6 - Toxic Substances | Keep Apart |
Class 8 - Corrosive Substances | Keep Apart |
Key:
Keep Apart:Dangerous goods of these Classes should be kept apart by at least 3m. Consult the SDS or supplier
Segregate:These combinations of dangerous goods should be segregated by at least 5m and kept in separate compounds or building compartments.
Isolate:This requirement applies to organic peroxides, for which dedicated stores or storage cabinets are recommended. Adequate separation from other buildings and boundaries is required.
Compatible:DangerousGoods of the same Class should be compatible; consult SDS or suppliers about requirementsfor individual substances.
SeparationFrom Ignition Sourcesand Protected Places
To reduce the risk of harm to people and property, flammable and combustible liquids such as oils must be separated from ignition sources and protected places. Combustible liquids storagefacilities must be separated from all ignition sources by a distance of at least 3metres. Stores of combustible liquids must also be separated from onsite protected places byatleast 3metres.
AS1940 defines an onsite protected place as:
A building where people are employed within the property boundary, including offices, warehouses, manufacturing or processing areas, amenities and other dangerous goods stores where quantities exceed minor storage.
Indoor Storage Of Engine Oil
AS1940 outlines different storage requirements for the indoor storage and the outdoor storage of combustible liquids.
Therefore, if you’re storing your engine oil in an indoor location, you should choose a safety cabinet that’sbeen manufactured in full conformance to AS1940.This type of safety cabinet is referred to as a flammable liquids storage cabinet orflammable cabinet.
If you’re storing your oil indoors, you must select a safety cabinet that’s been constructed to meet the requirements of AS 1940.
Features of a compliant flammable liquids cabinet include:
- The walls, floor, doors and roof of theflammable cabinetmust be constructed from a double walled sheet steel construction. The gap between these walls must be no less than 40mm and can be left empty or filled with a fire-resistant insulation.
- The gaps around the doors and the walls of theflammable storage cabinetshall be sealed to prevent heat radiation and the spread of flames in the event of a fire.
- The base of the cabinet shall form a liquid-tight sump of at least 150mm deep. This sump must be designed in such a way that packages are prevented from being stored in the sump. This sump will contain any spills that may occur inside the cabinet.
- The shelves inside the cabinet must be perforated to allow for free air movement inside the cabinet. The shelves should also be sturdy and capable of carrying the maximum possible load.
- The inside of thecabinetincluding the shelves shall be designed in such a way that any spills are directed into the sump in the base of the cabinet.
- The doors of the cabinet shall beself-closing, close-fitting and held shut automatically by catches at two or more points.
- If the doors are equipped with a device to hold the doors permanently open when the cabinet is being loaded, the doors must automatically close when the temperature exceeds 80°C.
- Materials that are critical to the structural integrity of the cabinet must not melt at temperatures below 850°C. Seals and gaskets are an exemption to this requirement.
How Are You Storing Oil In your Business?
As we’ve discussed in this blog, oils are not classified asClass 3 Flammable Liquidsbecause theydon’t emitenough flammablevapoursto ignite(in the presence of an ignition source)at temperatures below 60 °C. Even thoughengineoilsaren’tclassified as flammable liquids, they must be stored in full conformance to AS1940-the storage and handling of flammable and combustible liquids.You can achieve safe storage of your oils by following the requirements in the Australian Standard. You can alsolearn more about safe chemical storage by accessing our free eBookHow To Reduce The Risk Of Flammable Liquids In The Workplace. We’llalso introduce you to oureffective4-step risk control methodology—that you can easily apply to your own workplace. Get your copy of our helpful guide for free today.
