This Section is intended to address the hazards associated with the storage of flammable and combustible liquids in closed containers. The principal hazard of closed container storage is the possibility of rupture due to over pressure of the container when exposed to the heat of a fire. This release of liquid during the fire may cause the rupture of other containers resulting in a rapidly spreading fire. Fire tests show that automatic sprinklers designed for ordinary hazard combustibles may be inadequate to control a fire involving drums of flammable liquids or to prevent over pressuring of containers that are piled too high.
This Section applies to all storage except:
The United States Department of Transportation has increased the maximum allowable size of Intermodal Bulk Containers (IBC's) and portable tanks to 793 gal (3000 L). These tanks are transported to Canada and therefore Transportation of Dangerous Goods legislation permits their use. Although the Fire Code limits the size of the portable tanks to 2500 L, the general exemption of Part 4 to TDG would apply. Therefore the use of a TDG approved 3000 L IBC or portable tank would not be in contravention of the Fire Code.
(a) storage is to be arranged so that a means of egress or access to or from exits, elevators and principal routes are not obstructed or made impassable by radiant heat or flames if such storage were involved in a fire,
(b) the arrangement of containers provides stability to prevent toppling which could result in a container being damaged and leaking.
In order to provide stability of containers such as drums, skids should be used between vertical rows. Piling of drums should only occur onto full skids of drums. Plastic drums should not be used to support other loads because the heat from a fire may quickly melt them causing piles to topple and spill.
The physical and chemical stability of the product stored may be affected by the manner in which the products are stored, i.e. height of storage, temperature, base area of a storage pile, etc. The intent of Article 4.2.2.2. is to ensure that in addition to the provisions of this Section, the method of storage of flammable and combustible liquids are such that
Sentence 4.2.2.3.(1) specifies that flammable and combustible liquids be separated from other dangerous goods (i.e. products or substances which are regulated by the Transportation of Dangerous Goods Act) in conformance with Sections 3.2. (Indoor Storage) and 3.3. (Outdoor Storage) of the National Fire Code, 1995. Of particular interest is Table 3.2.7.6. of the NFC which specifies:
For the purpose of using this table, Class IIIA combustible liquids shall be treated as Class 3 dangerous goods.
WHMIS requires most containers to be clearly labeled. Part 4 requires that all other flammable or combustible liquid containers be labeled. These labels must state that the material is to be kept away from ignition sources and that the container be kept closed when not in use.
Glass or plastic containers may be permitted when such storage in metallic containers would adversely affect their chemical purity or would cause excessive corrosion of the container. Glass has the disadvantage that it is easily broken. Partially full plastic containers may quickly melt when exposed to heat.
Part 4 does not set out design or construction requirements for containers less than 1 L in size for Class I liquids and 5 L for Class II and Class IIIA liquids.
Small sample containers not meeting the specified regulations can be used for quality control purposes or for testing by regulatory officials.
The requirements of Articles 4.2.3.1., 4.2.3.3. and 4.2.3.4. can be summarized as follows:
Assembly occupancies can be generally defined as structures where groups of people gather for purposes such as deliberation, worship, entertainment or awaiting transportation but, for the purpose of this Subsection, does not include schools, colleges or universities.
Assembly occupancies usually contain persons who do not use the building frequently and, therefore, are not familiar with the location of exits, exit paths or other safeguards that may be present. In addition, many assembly occupancies such as theaters, concert halls, night clubs, lounges and some restaurants, involve a large number of people. These people may be exposed to conditions such as near total darkness which further increases the hazard to life safety. Therefore, assembly occupancies may only store limited quantities of flammable and combustible liquids in approved containers. These limits are:
Where two or more classes of liquids are stored in an assembly building, the maximum total quantity permitted is calculated based on the respective limit for each Class of liquid, such that the total does not exceed 1. For example, if storage were required for
This total exceeds 1. Thus, the quantities of the liquids are too large and would have to be reduced so that the total does not exceed 1. For example, if the following quantities were stored,
This total is acceptable.
Occupants in residential buildings, such as single family dwellings, apartments, etc., spend part of their time sleeping. A fire that occurs at night may result in a delayed response due to sleeping occupants. Storage of flammable and combustible liquids within a dwelling unit is restricted to a maximum of 30 L, of which not more than 10 L can be a Class I flammable liquid.
Where garages or sheds are attached to a dwelling unit, they may be used for the storage of up to 50 L of flammable and combustible liquids, of which not more the 30 L can be a Class I flammable liquid.
Article 4.2.3.1. states that containers for flammable or combustible liquids shall be built in conformance with one of the following:
Note that Section 8 of the Gasoline Handling Code also has requirements for acceptable containers.
Subsection 4.1.7. has requirements for ventilation which apply to all occupancies regardless of the quantity of flammable or combustible liquid being stored. However, Sentence 4.1.7.2.(2) states that ventilation is not required for the storage of Class I liquids provided that the storage consists only of closed containers and no dispensing operations are performed. This means the generator cannot be refueled in the room where the gasoline is stored. Both for fire safety reasons and to reduce potential problems from carbon monoxide, the generator should be located outside unless it is located in a room or building specifically designed for a fuel-fired appliance.
Subsection 4.1.6. requires that means be provided to contain any spill of gasoline that might occur. To limit the size of a spill, the gasoline should be stored in containers that do not exceed 25 L in size. The containment could take the form of a noncombustible, liquid-tight floor with a curb. Alternatively, the gasoline containers can be placed in a noncombustible, liquid-tight pan or tray of sufficient capacity to contain the contents of the largest container.
A fire extinguisher with a rating of at least 10BC should be located within 9 m of the gasoline storage area. Regardless of the quantity of gasoline stored, sources of ignition should be strictly controlled. To deter vandalism (or theft), the gasoline should be stored in a building or other enclosure which can be secured against unauthorized entry.
Where the quantity or method of storage of gasoline being stored outside a building constitutes a significant hazard, Subsection 4.2.11. may apply.
Since the container storage for this occupancy is for closed containerss only, with no dispensing, the likelihood of flammable vapours being present is very unlikely. Therefore, storage of these closed containers is permitted in the basements of mercantile occupancies. To further reduce the possibility of a flammable vapour release, stacking heights of the closed containers is restricted to a maximum height of 1.5 metres, or 1 metre for individual fixed shelves. This height should prevent accidental toppling which could result in a container leakage. Where provided, or required, the sprinkler protection must be installed in accordance with NFPA 13, "Standard for the Installation of Sprinkler Systems", and designed to NFPA 30.
Article 4.2.5.3. addresses the potential hazard where flammable vapours are released during transfer operations. It was not the intent to prohibit the opening of small paint containers in retail areas for the purpose of tinting. Containers up to 21 L are routinely used in the retail industry. Since the surface area of the exposed liquid is not significantly greater with the larger containers, the amount of vapour released from these containers is not significantly increased from that of a container of 5 L. Therefore, tinting operations involving paint containers not exceeding 25 L in capacity may be carried out in mercantile occupancies outside of a room conforming to Subsection 4.2.9.
It is not the intent of this article to prohibit the opening of small paint containers in retail areas for the purpose of tinting.
Where excess quantities need to be stored, this storage shall conform to Subsection 4.2.7.
In order to ensure that the combustible loading within buildings will not increase to levels that could create a threat to life safety, the maximum quantities of flammable and combustible liquids have been specified. Excess quantities may be stored in a storage cabinet conforming to Subsection 4.2.10. or in a storage room that conforms to Subsection 4.2.9. provided there are no openings into the public areas of the building.
Article 4.2.7.1. specifies that this Subsection applies to storage of flammable and combustible liquids in closed containers in industrial occupancies.
The application of this Subsection should also include handling and use of flammable and combustible liquids in closed containers in industrial occupancies. This Subsection makes reference to conditions that must be satisfied when liquids are handled and used. Dispensing or transfer operations are only permitted in conformance with Subsections 4.2.8. or 4.2.9., or Sentence 4.2.7.4.(2).
Article 4.2.7.2. refers to other articles which set out storage requirements for areas, rooms, cabinets and incidental use.
The storage of larger quantities of flammable and combustible liquids often found in industrial occupancies represents the potential for significant fire risk. Article 4.2.7.3. requires a fire compartment to be separated from the remainder of the building by a fire separation having a fire-resistance rating of at least 2 hours.
Article 4.2.7.4. permits dispensing and transfer of Class I or II liquids in a smaller storage area of not more than 100 m2 where the requirements set out in Subsection 4.2.9. have been met. Some limited dispensing is also permitted as in Subsection 4.2.8., provided precautions set out in that Subsection are met. Otherwise, dispensing or transfer of Class I or II liquids must be conducted in separate rooms that conform to Subsection 4.2.9.
Article 4.2.7.5. sets out the maximum permissible storage quantities of flammable and combustible liquids in closed containers for industrial occupancies. The maximum quantities of flammable or combustible liquids that can be stored are outlined in Tables 4.2.7.A. and 4.2.7.B. However, when buildings dedicated to the storage of such liquids are separated from other adjacent buildings, either by a spatial separation (Ontario Building Code 3.2.3.) or by a 4 hour firewall, and these buildings are protected by automatic sprinkler systems installed in accordance with Article 4.2.7.7., the maximum quantities of such liquids are not limited.
The limits on the quantities may be exceeded if a suitable compliance equivalency under Article 4.1.1.5. is approved. The compliance equivalency should include the following features:
Frequently, industrial storage involves liquids of different flash points stored in the same area. The maximum quantity of liquids may be calculated according to the following example:
For an unsprinklered industrial occupancy located on the first storey:
| 1000 |
| 500 |
| 50 |
| 250 |
This amounts to the following quantities:
| Class IA - | 1000 x 4 = 4,000 liters |
| Class IC - | 500 x 20 = 10,000 liters |
| Class II - | 50 x 205 = 10,250 liters |
| Class IIIA - | 250 x 205 = 51,250 liters |
The maximum quantity permitted is determined
by the requirements of Sentence 4.2.7.5.(4) as follows (refer
to Table 4.2.7.5.A for unprotected storage):
4000/2500 + 0/10000 + 10000/10000 + 10250/30000 + 51250/10000
= 1.6 + 0.0 + 1.0 + 0.34 + 0.51 = 3.45
This total exceeds 1. Therefore, the quantities of the various classes of liquids are too large for an unprotected area. Two alternatives are available to comply with the requirements:
a) reduce the quantities of liquids
to be stored or
b) sprinkler protect the storage area
in conformance with Table 4.2.7.5.A. for protected storage on
the first storey.
If the area is sprinklered, the
maximum quantities permitted are as follows:
4000/50000 + 0/60000 + 10000/60000 + 10250/10000 + 51250/200000
= 0.08 + 0.0 + 0.167+ 0.103 + 0.256
= 0.606
This total is now less than 1 and, thus,
acceptable.
Sentence 4.2.7.5.(2) sets no limit to the total quantity of flammable and combustible liquids in a separate or detached storage building. Although total quantity limits of Tables 4.2.7.A and 4.2.7.B do not apply, the quantity and height limitations specified for the individual storage areas must be met to take advantage of the exemption for total quantity limits.
With the current wording in the Fire Code, it is not obvious how to deal with a mixture of solid piled and rack storage. When flammable or combustible liquids are stored in a single fire compartment in solid pile or rack storage configurations or a combination of both, the maximum quantity permitted for each class should be calculated as follows:
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The calculations are based on proportional amounts of each type of liquid that is stored in a particular configuration, i.e. rack storage or solid piled. The modified formula clarifies how the maximum quantities can be determined when storage is provided in either solid piled or rack storage configurations or a combination of both. The modified formula accommodates both a single class of liquid or "2 or more classes" of liquid stored in both rack and solid pile arrangement.
Although Article 4.2.7.7. is located in Subsection 4.2.7., the provisions of this Article would apply wherever protection is required in Part 4. Where protection is required by this Part, a sprinkler system installed in conformance with NFPA 30, "Flammable and Combustible Liquids Code", or a fire extinguishing system installed in conformance with the appropriate standard would be considered to meet the intent of the code. Appropriate standards for the installation of fixed fire extinguishing systems are:
It should be noted that this list contains standards that are not included in Article 6.8.1.1. Acceptance of a fixed extinguishing system based on a standard not included in Article 6.8.1.1. must be based on the submission of a compliance equivalency under Article 4.1.1.5.
Article 4.2.7.7. sets out two options for fixed fire suppression systems including those set out in Section 6.8 Special Extinguishing Systems (e.g. foam sprinkler, water spray, carbon dioxide, dry chemical systems) or sprinkler protection as set out in NFPA 30, "Flammable and Combustible Liquids Code".
Sentence 4.2.7.8.(1) specifies a minimum clearance of 450 mm between the top of storage and the lowest structural members, sprinkler head deflectors or other overhead fire protection system components. This clearance is required to ensure that a proper spray pattern from the sprinkler head can be formed.
Sentence 4.2.7.8.(2) requires a wall clearance of 400 mm unless the depth of storage between an aisle and the wall does not exceed 1.5 metres. This arrangement is intended to permit visual inspection of the containers and to assist in fire fighting activities.
Article 4.2.7.9. requires (except as provided in 4.2.7.10.) that aisles be provided allowing access for fire fighting purposes to all portions of the storage. This article Article refers to Article 3.2.2.2. of the National Fire Code which specifies that aisles must be not less than 1.0 metre wide to access fire protection equipment and access panels. Where storage rooms are larger than 100 m², they shall be provided with at least one main access aisle. This main aisle must have a minimum width of 2.4 metres for storage heights of not more than 6 metres and 3.6 metres for storage heights of more than 6 metres. If the building is sprinklered and the products are stored in racks, the main access aisle does not need to exceed 2.4 metres in width. The main access aisle must be accessible from at least 2 fire department access points, preferably located as remote from each other as possible. All aisles must be kept clear of obstructions. Dead-end aisles should be minimized because of the risks they present to occupants during egress. Fire department access to storage areas may be provided by doors or access panels directly from the outdoors or through another fire compartment in the building.
Article 4.2.7.11. requires that combustible materials other than those used for packaging of flammable or combustible liquids not be stored in the same individual storage area with containers of flammable and combustible liquids. Examples of combustible materials include piled empty pallets, paper products, lumber, plastics and polyurethane foam.
Article 4.2.7.12. requires absorbent materials to be available to clean up spills of flammable or combustible liquids. These absorbent materials must conform to ULC/ORD-C410A. Clean-up and disposal procedures must also conform to requirements set out in Part X (Spills) of the Environmental Protection Act.
Article 4.2.7.13. requires storage areas to be ventilated in conformance with Subsection 4.1.7.
Maximum quantities of flammable and combustible liquids are specified. These quantities may be exceeded where normal plant activities require larger volumes, however, these quantities should not exceed more than the supply for one day of activity.
The references to the NFC in Article 4.2.8.4. have caused some confusion in the past. The intent of Sentence (2) may be summarized as follows:
providing a level of protection not less than that required for Class IV commodities stored up to a height of 6 m. This summary better conveys the intent of the requirement.
Article 4.2.9.1. requires that rooms where flammable and combustible liquids are stored have a fire separation from the rest of the building as specified in Table 4.2.9.A. This table allows quantities to be doubled where the storage room is protected by an automatic fire suppression system that conforms to Article 4.2.7.7. Class I liquids stored in an unprotected storage room having a fire-resistance rating of at least 2 hours shall not exceed the maximum quantities specified for unprotected storage in Table 4.2.7.A. and shall comply with Sentences 4.2.7.5.(3) and (4).
Article 4.2.9.2. specifies provisions for spill control of flammable and combustible liquids. This article refers to Subsection 4.1.6. for design requirements of these systems. In most cases, the more strict requirements set out in the Industrial Regulations under the Occupational Health and Safety Act will require that a drain be installed that is connected to a dry sump or holding tank. This is an existing requirement that is designed to protect worker health and safety during spill clean-up. Subsection 4.1.6. specifies that the system be designed to contain any spill, including water used for fire fighting purposes. For design purposes, the containment system should be able to retain water discharged from automatic suppression systems and manual fire fighting hoses.
For the purposes of this regulation, these volumes can be estimated from the flows and durations set out in Table 5-2.3 (i.e. Hose Stream Demand and Water Supply Duration Requirements) and Figure 5-2.3 (i.e. area/density curves for automatic sprinkler design) in NFPA 13. The containment systems should be of sufficient height to contain the spill or divert the spill to a drainage system that will not create a fire hazard or any risk to health or safety or the natural environment and direct the spill away from buildings, means of egress, ffire department access roadways, or valves controlling the flow of flammable or combustible liquids or water supplies for fire fighting. Walls of the room must be liquid-tight where they join the floor to prevent flammable and combustible liquid spills from seeping into other areas.
In most cases, the storage, fire suppression and containment system should be designed by an engineer or architect familiar with the risks associated with flammable and combustible liquid storage. This engineer or architect should also be familiar with alternate strategies to reduce fire fighting run-off water such as by using automatic foam suppression systems.
Article 4.2.9.3. specifies that these storage rooms must be provided with ventilation in accordance with Subsection 4.1.7.
Article 4.2.9.4. requires access aisles of at least 1 metre width. This is intended to permit unrestricted access to all room exits and to fire protection equipment (i.e. sprinkler control valves, fire hose stations, fire alarm stations, and portable fire extinguishers).
Article 4.2.9.5. requires the use of a pump, self-closing valve or faucet designed in conformance with good engineering practice when dispensing flammable or combustible liquids containers from containers having a capacity of more than 30 L.
Article 4.2.9.6. now sets the minimum standard to which explosion venting must be provided when required by the Fire Code.
Article 4.2.9.6. specifies that for rooms where Class IA or IB liquids are dispensed, explosion venting must be provided. Explosion venting consists of devices designed to open at a predetermined pressure to relieve the internal pressure build-up within the room, thereby preventing major structural and mechanical damage to the building. NFPA 68 sets out good engineering practices. Deflagrations must be safely vented into areas not normally occupied by workers or the public.
Article 4.2.9.7. requires that portable fire extinguishers be provided for this storage and/or dispensing room as specified in Section 6.2 of the Ontario Fire Code.
Article 4.2.9.8. specifies the exiting requirements set out in the Industrial Regulations under the Occupational Health and Safety Act regarding egress from a dispensing room that has an area greater than 15 m2 or the travel distance from any part of the room exceeds 4.5 metres. These requirements include exit doors that swing outwards, a door located within 23 metres from any point in the room, and at least two exits located at least three-quarters of the maximum diagonal dimension of the room from each other.
Often, specially constructed cabinets are used to store limited quantities of flammable and combustible liquids in closed containers. Since these cabinets and their contents may constitute a significant fire load, the total volume of these liquids is limited to 500 L of which not more than 50% may be a Class I liquid. Up to three times this volume of liquids may be stored in a group of these specially designed cabinets within a fire compartment. In an industrial occupancy, additional groups of cabinets may be stored in the same fire compartment provided each group of cabinets is separated by a distance of at least 30 metres. Institutional occupancies must not exceed the volume limitations set out for one cabinet for each fire compartment.
Cabinets shall be clearly labeled to indicate that they contain flammable materials and that all open flames must be kept away from the cabinet. Usually these cabinets are painted red or yellow.
These cabinets must be designed to provide a degree of fire protection for their contents. The cabinets must be constructed such that the internal temperature rise is limited to 1390C above ambient temperature when the entire cabinet is subjected to a standard fire test for 10 minutes.
Cabinet ventilation may be provided as long as the vents terminate outside the building and the vent line is constructed of steel piping. Cabinets not provided with vent lines must have the vent openings in the cabinet stopped with a metal plug.
Many cabinets, both existing and new, are not listed or approved to the ULC standard. Other listed cabinets such as FM approved, listed to NFPA 30, or ULI that have comparable performance to the ULC standard are acceptable.
Sentence 4.2.11.1.(2) allows the minimum separation distance from a storage pile (e.g. drums) to a buildings to be waived where 5000 liters or less of flammable or combustible liquids are stored adjacent to a one storey flammable or combustible liquid storage building or where the exposed building wall has a 2 hour fire-resistance rating with no openings in the wall within 3 metres of such outdoor storage.
Article 4.2.11.2. specifies that for situations where outdoor storage piles involve liquids of varying flash points, the maximum quantity permitted in the pile shall equal the quantity permitted for the liquid with the lowest flash point.
Article 4.2.11.3. requires an access lane with a minimum width of 6 metres to be provided to allow fire department vehicles to within 60 metres of any part of the pile to carry out fire fighting activities.
Article 4.2.11.4. requires spill control measures that conform to Subsection 4.1.6. This Subsection requires the safe containment of all flammable and combustible liquids and contaminated water used in fire fighting activities.
Arson has proven to be a significant ignition source where security measures have been absent. Therefore, Article 4.2.11.5. requires outdoor container storage areas to be enclosed by a fence at least 1.8 metres in height and equipped with gates which are kept locked unless the facility is staffed.
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