NFPA has released the 2012 edition of NFPA 30 – Flammable and Combustible Liquids Code. There are some changes in this new 2012 edition. They are intended to respond to newly identified risks:
- new provision requires that Class II and Class III liquids stored, handled, processed, or used at temperatures at or above their flash points follow all applicable requirements in the Code for Class I liquids, unless an engineering evaluation deems otherwise.
- 9.3.12 Storage, handling, and use of Class II and Class III liquids heated at or above their flash point shall follow the requirements for Class I liquids, unless an engineering evaluation conducted in accordance with Chapter 6 justifies following the requirements for some other liquid class. (See 6.4.1.2 and A.6.4.1.2.)
- An annex item explains that the use of spark-resistant tools must be evaluated on a case-by-case basis.
- A.6.5.1(8) With respect to frictional heat or sparks, it is recognized that there is a need to control sources of ignition, including mechanical sparks from hand tools, that have sufficient energy to ignite flammable vapors. Studies, anecdotes, codes, and referenced standards (e.g., API 2214, Spark Ignition Properties of Hand Tools) show that there is a potential for hand tool sparks to ignite flammable vapors from a limited number of chemicals and under certain unique conditions. These include flammable liquids with low minimum ignition energies, operations in which flammable or combustible liquids are heated, and atypical spark generation that can occur between specific types of hand tools and struck surfaces (i.e., thermite reactions or impact of steel tools on quartzitic materials). Even spark-resistant tools might not provide suitable protection against ignition. For example, hard metal particles can become imbedded in the relatively soft metal of spark-resistant tools, and these particles can cause sparks when the tools are used.
- NFPA 30 requires analyses, such as job safety analyses or activity hazard analyses, of the hazards and risks of a given task and the application of appropriate protective measures to prevent or mitigate the hazards and risks. This includes identification and mitigation of ignition risk from multiple sources, including hand tools. Due to the complexity of the numerous operations involving flammable liquids, NFPA 30 cannot address all conditions in which spark-resistant tools should be made mandatory, might be advisable, or are unnecessary to help control the ignition risk of any given operation.
- In response to U.S. DHS rules requiring security/vulnerability assessments for high-hazard facilities, new Section 6.10 and an accompanying Annex H have been added to address management of facility security by means of a mandatory security and vulnerability assessment. Annex G provides an outline of a suggested assessment process.
- New annex guidance covers selecting a safe location to which a flammable liquids storage cabinet may be vented, and selecting a safe location to which a flammable liquids dispensing area may be vented.
- A.9.5.4 Venting of storage cabinets has not been demonstrated to be necessary for fire protection purposes. Additionally, venting a cabinet could compromise the ability of the cabinet to adequately protect its contents from involvement in a fire, because cabinets are not generally tested with any venting. Therefore, venting of storage cabinets is not recommended. However, it is recognized that some jurisdictions might require storage cabinets to be vented and that venting can also be desirable for other reasons, such as health and safety. In such cases, the venting system should be installed so as to not affect substantially the desired performance of the cabinet during a fire. Means of accomplishing this can include thermally actuated dampers on the vent openings or sufficiently insulating the vent piping system to prevent the internal temperature of the cabinet from rising above that specified. Any make-up air to the cabinet should also be arranged in a similar manner. If vented, the cabinet should be vented from the bottom with make-up air supplied to the top. Also, mechanical exhaust ventilation is preferred and should comply with NFPA 91, Standard for Exhaust Systems for Air Conveying of Vapors, Gases, Mists, and Noncombustible Particulate Solids. Manifolding the vents of multiple storage cabinets should be avoided.
- A.9.5.4.2 A “safe location” should be selected as the location of a vent discharge to minimize the potential for ignitible vapors to travel to a source of ignition after discharge from the vent. Electrical equipment that does not meet the requirements for hazardous locations can serve as an ignition source. The Technical Committee advises that vent discharge locations should consider such factors as the following: (1)Characteristics of the exhausted material (vapor density, toxicity, velocity of discharge, etc.)(2)Proximity to potential ignition sources, (3)Building openings such as doors, windows, air intakes, and so forth, (4)Dispersion characteristics (distance to discharge within the flammable range, direction of discharge, atmospheric conditions, and the influence of building and neighboring buildings on discharged vapors), (5)Likelihood of vapor accumulation following discharge, such as accumulation under building eaves, (6)Likelihood of sufficient discharge volume to allow an ignitible concentration to reach an ignition source. Historically, NFPA 30 has provided prescriptive guidance, often based on area classification requirements, and results have been acceptable. Closer distances should be accepted only if an analysis by a qualified person justifies closer distances. Similarly, the specified distances might not be acceptable for all installations, thus the guidance provided above.
- Provisions for flammable liquids storage cabinets incorporate more extensive marking requirements.
- 9.5.5* Storage cabinets shall be marked as follows: WARNING: FLAMMABLE KEEP FIRE AWAY
- 9.5.5.1 The minimum letter height for FLAMMABLE (signal word) shall be 2.0 in. (50 mm) and the minimum letter height for KEEP FIRE AWAY (message) shall be 1.0 in. (25 mm).
- 9.5.5.2 All letters shall be uppercase and in contrasting color to the background.
- 9.5.5.3 The marking shall be located on the upper portion of the cabinet’s front door(s) or frame.
- 9.5.5.4 Use of other languages, the international symbol for “flammable” (a flame in a triangle), the international symbol for “keep fire away” (a burning match in “no” circle) shall be permitted.
- A.9.5.5 ANSI Z535.2.2007, Environmental and Facility Safety Signs, Section 9.2, was used to determine the letter height, based on a safe viewing distance of 25 ft (7.5 m). Markings can be reflective to improve visibility. If international symbols are used, they should be a minimum of 2.0 in. (50 mm) in size.
- Revised Table 9.9.1, Fire Resistance Ratings for Liquid Storage Areas, indicates that no fire resistance rating is required for separation walls for accessory use areas of small floor area.
- Revised Section 13.3 more clearly establishes the required separation between detached unprotected liquids storage buildings and both protected and unprotected exposed properties.
- Numerous minor amendments have been made to clarify application of the provisions of Chapter 16, Automatic Fire Protection for Inside Liquid Storage Areas.
- New Subsection 17.3.7 has been added to address process vessels used to heat liquids to temperatures at or above their flash points, as suggested by investigations conducted by the U. S. Chemical Safety and Hazard Investigation Board.
- 17.3.7 When a process heats a liquid to a temperature at or above its flashpoint, the following shall apply: (1) The process vessel shall be closed to the room in which it is located and vented to the outside of the building. (2) If the vessel needs to be opened to add ingredients, the room ventilation shall meet the requirements of Section 17.11 and the process heating controls will be interlocked with the ventilation such that the process heat will shut down if the ventilation fails or is turned off. (3) The process vessel shall be equipped with an excess temperature control set to limit excessive heating of the liquid and the subsequent release of vapors. (4) If a heat transfer medium is used to heat the liquid and the heat transfer fluid can heat the liquid to its boiling point on failure of the process and excess temperature heat controls, a redundant excess temperature control shall be provided.
- New provision clarifies that tightness testing is not required for an interstitial space of a secondary containment tank that maintains factory-applied vacuum.
- 21.5.2.1 Testing required by 21.5.2 shall not be required for a primary tank or an interstitial space that continues to maintain a factory-applied vacuum in accordance with the manufacturer’s instructions. Such components shall be considered to be tight until such time that the vacuum is broken. Final tightness testing of an interstitial space shall not be required if the factory-applied vacuum is maintained until one of the following conditions is met: (1) For aboveground tanks, the tank is set on the site at the location where it is intended to be installed. (2) For underground tanks, backfill has been completed to the top of the tank.
- A note and annex item for Table 22.4.2.1, Minimum Shell-to-Shell Spacing of Aboveground Storage Tanks, explain the term “sum of adjacent diameters” and its determination.
- A.22.4.2.1 Where more than two tanks are involved, the sum of the diameters of each possible pair of tanks is calculated. For example, assume four tanks in a common diked area, numbered 1 through 4 clockwise from tank #1. The diameter of each pair of tanks is summed, as follows: 1 and 2, 1 and 3, 1 and 4, 2 and 3, 2 and 4, and 3 and 4.
- Changes provide additional guidance on handling floating roof pontoons that have been breached by liquids or vapors.
- The Code no longer allows the use of water ballast to secure underground tanks in areas subject to flooding.
- A.23.14.1 Anchoring can be accomplished using nonmetallic straps or metallic straps that are separated from the tank shell by inert insulating dielectric material. The straps should be connected to a bottom hold-down pad or deadman anchors. For additional information, see reference to API RP 1615, Installation of Underground Petroleum Storage Systems; PEI RP100, Recommended Practices for Installation of Underground Liquid Storage Systems; and STI RP R011, Recommended Practice for Anchoring of Steel Underground Storage Tanks. Previous editions of NFPA 30 included provisions for the use of water ballast as a means to weight a tank to prevent movement during a flood. In anticipation of a flood event, water could be used to fill the tank to reduce buoyancy. While this approach remains technically viable for existing tanks that are not properly secured to prevent movement, the use of water as a means of providing ballast is no longer considered an acceptable basis of design for new tank installations. It is not the intent of this section to prohibit the use of water as ballast in underground tanks during system installation and prior to the initial introduction of the stored liquid.
- Use and installation of alcohol-based hand rub dispensers are now exempted from the Code.
- Revised definitions for the various types of building occupancies correlate NFPA 101®: Life Safety Code®.