Storage of Flammable Materials PDF

**Storage of Flammable Materials** INDOOR STORAGE OF FLAMMABLE LIQUIDS Flammable liquids must be stored in: - A flammable storage cabinet, - An inside storage room or cut-off room, or - A flammable storage warehouse. The amount of flammable liquid that may be stored in a particular area...

**Storage of Flammable Materials** INDOOR STORAGE OF FLAMMABLE LIQUIDS Flammable liquids must be stored in: - A flammable storage cabinet, - An inside storage room or cut-off room, or - A flammable storage warehouse. The amount of flammable liquid that may be stored in a particular area depends on the type of business and the location. Quantities are limited by the size of the room, its construction and fire resistance, and by its fire protection. Allowable quantities are given in total gallons per square foot of floor space. For instance, flammable liquid storage is prohibited in office areas, except for maintenance or operating the building or equipment. An exemption exists for "incidental storage" of flammable liquids for operations where "the use and handling of flammable liquids is only incidental to the principal business." Examples of these operations include automobile assembly, construction of electronic equipment, and furniture manufacturing. OSHA allows up to 25 gallons of Category 1 flammable liquid and 120 gallons of Category 2,3, or 4 flammable liquids in containers in any one fire area of a facility outside of protected storage. It also allows up to 660 gallons of a Category 2, 3, or 4 flammable liquid in a single portable tank. Note that the local Fire Marsal or liability insurance carrier may be more stringent. **Container Sizes** Remember that OSHA categorizes flammable materials in the following way: **Table B.6.1 from 29 CFR 1910.1200: Criteria for flammable liquids** **Category** **Criteria** -------------- ----------------------------------------------------------------------- 1 Flash point \< 23°C (73.4°F) and initial boiling point ≤ 35°C (95°F) 2 Flash point \< 23°C (73.4°F) and initial boiling point \> 35°C (95°F) 3 Flash point ≥ 23°C (73.4°F) and ≤ 60°C (140°F) 4 Flash point \> 60°C (140°F) and ≤ 93°C (199.4°F) Once flammable liquids are classified, storage requirements can be determined. Flammable liquids must be stored in a tank or in a container that complies with OSHA and NFPA. OSHA spells out maximum container sizes for each category of flammable materials and types of containers in 29 CFR 1910.106: OSHA Maximum Allowable Size of Containers and Portable Tanks for Flammable Liquids Container Type Category 1 Category 2 Category 3 Category 4 ---------------------------------- ------------ ------------ ------------ ------------ Glass or approved plastic 1 pt 1 qt 1 gal 1 gal Metal (other than DOT drums) 1 gal 5 gal 5 gal 5 gal Safety cans 2 gal 5 gal 5 gal 5 gal Metal drums (DOT specifications) 60 gal 60 gal 60 gal 60 gal Approved portable tanks 660 gal 660 gal 660 gal 660 gal Note: Container exemptions: (a) Medicines, beverages, foodstuffs, cosmetics, and other common consumer items, when packaged according to commonly accepted practices, shall be exempt from the requirements of § 1910.106(d)(2)(i) and (ii). Table from 1910.106(d)(2)(iii)(b) NFPA 30 has similar guidelines for maximum container sizes for each of its categories of flammable materials. **Storage Cabinets and Rooms** Flammable materials should be stored in a designated and approved fireproof cabinet or storage rooms as required by 29 CFR 1910.106. OSHA has specific requirements for flammable liquids storage cabinets. Cabinets must be labeled: FLAMMABLE -- KEEP FIRE AWAY. Metal cabinets must be constructed with at least 18-gauge sheet iron and double-walled, with 1½ inch air space. The doorsill must be at least 2 inches above the bottom of the cabinet. NFPA 30, Flammable and Combustible Liquids Code, does not require venting for fire protection purposes. Venting of flammable storage cabinets is permitted if vented directly to the outside, but is not required. If the storage cabinet is not vented, the bung in the cabinet must be in place. Note that OSHA doesn't require flammable cabinets to be grounded, but NFPA 77 does. In addition, local fire codes or insurance companies may require grounding flammable storage cabinets. **Storage Rooms** When larger quantities of flammables must be stored prior to use, a specific room designed to store flammable liquids safely should be constructed and utilized. The room should have electrically classified fixtures and wiring methods (per the National Electrical Code or NFPA 70), high- and low-point ventilation, fire-resistant walls and ceiling, blowout panels (weak spots designed to fail in the event of an explosion or overpressurization), and a method to capture spills (sumps, ramps, or dikes) per § 1910.106(d)(4)(i). The room must have a ventilation system capable providing at least 6 air changes per hour (6 ACH). All forklift trucks used in such a room are required to be rated for use in a flammable environment. Every inside storage room must have an aisle at least 3 feet wide to allow easy movement in the room. The aisle space also reduces the potential for damaging containers and spilling their contents and provides an easy way out of or into the room in an emergency. Containers of 30 gallons or more may not be stacked on top of one another in indoor storage rooms. OSHA's general industry 29 CFR 1910.106 and construction 29 CFR 1926.152 standards also identify total allowable quantities in gallons per square foot of floor area for inside storage rooms based on the fire-resistive rating of the room. When quantities of flammable liquids exceed these limits, separate external buildings, designed for the storage and/or use of flammable liquids, are required, and OSHA provides tables of quantities and locations (floor) for such purpose in Tables H-14 and H-15 of 29 *CFR* § 1910.106. Storage in Inside Rooms +-----------------+-----------------+-----------------+-----------------+ | Fire | Fire Resistance | Maximum Size | Total Allowable | | Protection^1^ | | | Quantities | | Provided | | | | | | | | (gal./sq. | | | | | ft./floor area) | +=================+=================+=================+=================+ | Yes | 2 Hours | 500 sq. ft. | 10 | +-----------------+-----------------+-----------------+-----------------+ | No | 2 Hours | 500 sq. ft. | 5 | +-----------------+-----------------+-----------------+-----------------+ | Yes | 1 Hours | 150 sq. ft. | 4 | +-----------------+-----------------+-----------------+-----------------+ | No | 1 Hours | 150 sq. ft. | 2 | +-----------------+-----------------+-----------------+-----------------+ While OSHA provides these requirements, NFPA 30 also specifies maximum allowable quantities of liquids allowed in a fire control area. Quantities can be increased 100% if the flammable liquids are stored in approved flammable liquids storage cabinets or in safety cans, and increased another 100% if the building is equipped with an automatic sprinkler system. Building codes have similar limitations and may also limit the amount of flammable materials storage in higher floors of a multi-story building. **Outdoor Storage** Outside areas where flammable liquids are being used or stored have adequate fire controls such as working hoses, portable fire extinguishers, and other fire control devices. OSHA requires at least one portable fire extinguisher with a rating of not less than 12-B units to be placed: 1\. Outside of indoor storage rooms, but not more than 10 feet from the door to the storage room; and 2\. Not less than 10 feet and not more than 25 feet from and Category 1, 2, or 3 flammable liquid storage area inside a building. Up to 1,100 gallons of flammable liquids may be stored next to a building located on the same premises as long as there is at least 10 feet of space between buildings and the nearest container of flammable liquid. The storage area must be sloped or graded to keep spills from reaching buildings a curb at least 6 inches high is installed. The outside area should be secured and free from weeds, debris, and other combustible materials. **Compatibility** Flammables should not be stored with the following: - Oxidizing agents such as chlorates, nitrates, perchlorates, permanganates, and peroxides. They usually do not combust on their own but provide the oxygen to accelerate the combustion rate of other chemicals. - Corrosive chemicals (acids or bases that destructively attack organic and inorganic material). Common acids include sulfuric acid (battery acid), acetic acid, and nitric acid. Although acetic acid and nitric acid are both acids, they are incompatible. Common alkalis (bases) include ammonium hydroxide, calcium oxide (lime), and sodium hydroxide (lye). - Materials susceptible to spontaneous heating and/or explosions. Hydrogen peroxide contacting combustible material can result in spontaneous combustion. Picric acid can be explosive. - Substances that react with air or moisture to create heat. Sulfuric acid is a corrosive that reacts violently with water. Avoid storing flammables in direct sunlight or near other heat sources; eliminate all sources of ignition. Keep the area dry and cool. Use explosion-proof refrigerators designed for chemical storage when chemicals require extra cool temperatures. **Electrical Protection** The use of electricity around flammable solvents poses a hazard unless used correctly. Both electricity and static electricity can be ignition sources for flammable liquids. Store flammable materials at least 25 feet away from open flames, sparks, heat, or other ignition sources unless separated by a fire-resistant barrier with a fire-resistance rating of at least 1 hour. Wiring that is in the vicinity of flammable liquids must meet the requirements listed in § 1910, Subpart S, or in the National Electrical Code. To prevent the buildup of static charges, containers of flammable liquids must be grounded and bonded. OSHA's 29 CFR 1910.106 states, "Category 1 or 2 flammable liquids, or Category 3 flammable liquids with a flashpoint below 100°F (37.8°C), shall not be dispensed into containers unless the nozzle and container are electrically interconnected." OSHA's construction flammable liquids standard (29 CFR 1926.152) requires transfer of all category 1, 2, and 3 flammable liquids from one container to another be done only when the containers are electrically interconnected (bonded). NFPA 30 also addresses the need for bonding and grounding. *Grounding* is a wire that connects the metal container with an earth or building ground. *Bonding* is a jumper wire that goes from the supply container to the filling container to ensure that both containers are electrically neutral to each other, so there is no chance for a spark  In general, when being filled, metal containers and associated fill equipment should be bonded together and grounded. When dispensing from an upright drum, any dip pipe, conductive hose, or pump should be bonded to the drum and grounded. NFPA 77, *Recommended Practice on Static Electricity* provides guidance on proper bonding and grounding methods for a variety of container and dispensing types that should be followed. **Working with Flammable Solvents** While most states have passed laws that prohibit smoking inside buildings, but the regulations in §1910.106(f)(6) still require \"No Smoking\" signs conspicuously posted where hazard from flammable liquid vapors is normally present. Hot work, such as welding or cutting operations, use of spark-producing power tools, and chipping operations shall be permitted only under supervision of an individual in responsible charge. The individual in responsible charge shall make an inspection of the area to be sure that it is safe for the work to be done and that safe procedures will be followed for the work specified. Such work should be performed upon approval in the form of a "hot work" permit. OSHA has several regulations that require such permit: - § 1910.106: Flammable Liquids - § 1910.119: Process Safety Management of Highly Hazardous Chemicals - § 1910.272: Grain Handling Facilities - § 1910.146: Permit-Required Confined Space - § 1910.252: Welding, Cutting, and Brazing There are also references to hot work in the construction, maritime, shipyard, and longshoring standards. When hot work is to be performed in or around flammable liquids, the area must be cleared of other combustible materials (paper, rags, oily materials, etc.) for a radius of 35 feet, per § 1910.252(a). A fire watch or firewatcher is required. This is a person who must stay by the hot work area and be on the lookout for a possible flare-up where the work was performed. They are required to have a fire extinguisher, be trained on how to use it, have a means of communication or a way to sound the alarms, and stay at that post for at least 30 minutes after the hot work has been completed. See § 1910.252(a)(iii)(B). However, there may be local requirements to have the fire watch maintained for more than 30 minutes.