The Revised NFPA 30

The Flammable and Combustible Liquid Code has been in use for 90 years. Its 2003 version is the finest yet.

• By Philip Fillweber
• Dec 01, 2003

FOR almost a century, NFPA 30 has guided users of flammable and combustible liquids. From 1913 to 1957, the document was published as a model municipal ordinance. In 1957, the format was changed to a code, although the technical requirements and provisions remained the same.

During its 90-year existence, the code has undergone constant revision as dictated by changes in technology and common sense experience. Revised editions are published about every three years. The 2003 edition adopted in mid-year has been reorganized for clarity and, according to its own introductory comments, incorporates the following changes:
(1) All mandatory referenced publications have been consolidated into a new Chapter 2 and all definitions into a new Chapter 3. All subsequent chapters have been renumbered accordingly.
(2) Numerous occupancy definitions have either been added or corrected to correlate with NFPA 1, Uniform Fire Code^TM; NFPA 101®, Life Safety Code®; and NFPA 5000^TM, Building Construction and Safety Code^TM.
(3) Separation distance requirements have been reduced in Table 4.3.2.1.1(a) for protected aboveground tanks, and separation distance requirements for tanks in vaults constructed in accordance with 4.2.7 have been eliminated.
(4) Special operating requirements have been added in 4.6.1.5 for shop-fabricated aboveground tanks with abnormally long vertical piping for fill and/or vent lines.
(5) New criteria have been added for maximum allowable container sizes in Table 6.2.3 in appropriate paragraphs of Chapter 6.
(6) A new Table 6.8.2(k) contains fire protection design criteria for unsaturated polyester resins, including appropriate amendments to Figure 6.8.2(a) and Figure 6.8.5.
(7) A new Annex D.5 contains suggested fire protection design criteria using high-expansion foam systems for protection of liquids in 1-gallon plastic containers.
(8) Revisions have been made to the Section 7.3 spacing requirements and construction requirements for process buildings.
(9) Special requirements have been added in Section 7.4 for insulated piping for recirculating heat transfer systems.
(10) A new 7.13.3.2 provides guidance prohibiting permanent interconnections between fire water systems and process water systems.

Each of these changes is significant. A careful reading of the current edition is encouraged. All changes from the 2000 edition are clearly indicated to facilitate your understanding. Also, studying in conjunction with NFPA 1, Uniform Fire Code^TM and NFPA 5000^TM, Building Construction and Safety Code^TM will be very helpful.

Scope of the Code
As we begin our examination of this revised code, let's clearly define its scope. The document itself states:
1.1.1 *This code shall apply to the storage, handling, and use of flammable and combustible liquids, including waste liquids, as herein defined and classified.

1.1.2 This code shall not apply to the following:(1) *Any liquid that has a melting point equal to or greater than 37.8^o C (100^o F) or that does not meet the criteria for fluidity given in the definition for liquid in Section 1.7.
(2) Any liquefied gas or cryogenic liquid as defined in Chapter 3.
(3) *Any liquid that does not have a flash point, but which is capable of burning under certain conditions; such liquids include certain halogenated hydrocarbons and certain mixtures of flammable or combustible liquids and halogenated hydrocarbons.
(4) *Any aerosol product.
(5) Any mist, spray, or foam.

1.1.3 This code shall also not apply to the following:
(1) *Transportation of flammable and combustible liquids as governed by the U.S. Department of Transportation.
(2) *Storage, handling, and use of fuel oil tanks and containers connected with oil-burning equipment.

Its purpose is to provide reasonable requirements for the safe storage and handling of flammable and combustible liquids. What exactly is a flammable liquid? What is a combustible liquid? They are not the same. By definition:

Flammable Liquid. Any liquid that has a closed-cup flash point below 100^o F (37.8^o C), as determined by the test procedures and apparatus set forth in 1.7.4. Flammable liquids are classified as Class I as follows: Class I Liquid--any liquid that has a closed-cup flash point below 100^o F (37.8^o C) and a Reid vapor pressure not exceeding 40 psia (2068.6 mm Hg) at 100^o F (37.8^o C), as determined by ASTM D 323, Standard Method of Test for Vapor Pressure of Petroleum Products (Reid Method). Class I liquids are further classified as follows: (1) Class IA liquids--those liquids that have flash points below 73^o F (22.8^o C) and boiling points below 100^o F (37.8^o C); (2) Class IB liquids--those liquids that have flash points below 73^o F (22.8^o C) and boiling points at or above 100^o F (37.8^o C); (3) Class IC liquids--those liquids that have flash points at or above 73^o F (22.8^o C), but below 100^o F (37.8^o C).

To simplify, think of a "flammable" liquid as a liquid that gives off enough vapor to form an ignitable mixture with air at ambient temperatures (less than 100^o F).

Combustible Liquid. Any liquid that has a closed-cup flash point at or above 100^o F (37.8^o C), as determined by the test procedures and apparatus set forth in 1.7.4. Combustible liquids are classified as Class II or Class III as follows: (1) Class II Liquid--any liquid that has a flash point at or above 100^o F (37.8^o C) and below 140^o F (60^o C); (2) Class IIIA--any liquid that has a flash point at or above 140^o F (60^o C), but below 200^o F (93^o C); (3) Class IIIB--any liquid that has a flash point at or above 200^o F (93^o C).

A combustible liquid must be heated to a temperature of 100^o F to emit sufficient vapors to form an ignitable mixture with the air. A "combustible" liquid is "safer" to handle than a "flammable" liquid only if the working temperature remains below its flashpoint.

Flammables and combustibles are among the most widely used hazardous materials throughout industry and commerce. As such, they are regulated by both the Occupational Safety and Health Administration and the Department of Transportation. The OSHA standard closely parallels the National Fire Protection Association's Code 30. Differences occur simply because OSHA has not kept pace with revisions in Code 30.

Container and Portable Tank Storage
Let's examine the section relating to container and portable tank storage. It applies to the storage of liquids in drums or other containers that do not exceed 450 liters, in portable tanks that do not exceed 2,500 liters, or IBCs (Intermediate Bulk Containers) with capacities of 5,000 liters or less.

Overpack Drums used to temporarily hold containers that do not exceed 230 liters also are subject to Code 30. A significant change throughout the 2003 Edition is the use of the metric system as the primary reference. English measurements are referred to parenthetically.

Table 6.2.3 in the latest edition of NFPA 30 is self-explanatory and is critical to compliance.

In addition to the primary use of metric measurement, the 2003 Table differs from its 2000 counterpart s follows:
(1) The current table makes a distinction between composite IBCs with "rigid inner receptacles" and those with "flexible inner receptacles."
(2) The reference to DOT specification 34 appearing in the "Polyethylene" line item in 2000 has been deleted.

Storage Cabinets and Safety Cans
Flammable liquid storage cabinets and safety cans are found almost everyplace flammables are stored or used. Readers will find no changes relative to cabinets.

Highlights are: (1) The volume of Class I, Class II, and Class IIIA Liquids in a cabinet is limited to 454 liters or 120 gallons. (2) Up to three storage cabinets may be located in a single fire area. In an industrial occupancy, this may be increased to six if minimum distance of 100 feet separates the groups of three cabinets. (3) Cabinets are not required to be vented. (4) Cabinets meeting at least one of the following sets of construction requirements are acceptable:
(1) Storage cabinets that are designed and constructed to limit the internal temperature at the center of the cabinet and 25 mm (1 in.) from the top of the cabinet to not more than 163^o C (325^o F), when subjected to a 10-minute fire test that simulates the fire exposure of the standard time-temperature curve specified in NFPA 251, Standard Methods of Tests of Fire Endurance of Building Construction and Materials, shall be acceptable. All joints and seams shall remain tight and the door shall remain securely closed during the test.
(2) Metal storage cabinets that are constructed in the following manner shall be acceptable:
(a) The bottom, top, door, and sides of the cabinet shall be at least No. 18 gauge sheet steel and shall be double-walled with 38 mm (11/2 in.) air space.
(b) Joints shall be riveted, welded, or made tight by some equally effective means.
(c) The door shall be provided with a three-point latch arrangement, and the door sill shall be raised at least 50 mm (2 in.) above the bottom of the cabinet to retain spilled liquid within the cabinet.
(3) Wooden cabinets constructed in the following manner shall be acceptable:
(a) The bottom, sides, and top shall be constructed of exterior grade plywood that is at least 25 mm (1 in.) thick and of a type that will not break down or delaminate under fire conditions.
(b) All joints shall be rabbetted and shall be fastened in two directions with wood screws. Where more than one door is used, there shall be a rabbetted overlap of not less than 25 mm (1 in.)
(c) Doors shall be equipped with a means of latching and hinges shall be constructed and mounted in such a manner as to not lose their holding capacity when subjected to fire exposure.
(d) A raised sill or pan capable of containing a 50 mm (2 in.) depth of liquid shall be provided at the bottom of the cabinet to retain spilled liquid within the cabinet.
(4) Listed storage cabinets that have been constructed and tested in accordance with (1) shall be acceptable.

The definition of a safety can has been changed sightly because of the conversion to the metric system. Maximum capacity, 20 liters, equates to 5.3 gallons instead of 5 gallons. The current definition reads: "A listed container, of not more than 20 L. (5.3 gal.) capacity, having a spring-closing lid and spout cover and so designed that it will safely relieve internal pressure when subjected to fire exposure." The conversion also results in increasing the volume of Class 1A liquids permitted in safety cans to 2.6 gallons from 2 gallons in earlier codes. 2.6 gallons of any Class I liquid is also now acceptable in office, education, and institutional occupancies, providing the liquid is in a "safety can."

Automatic fire protection for inside storage is a must for the storage of liquids in containers and portable tanks. "Decision trees" are provided to assist in the selection of the appropriate fire protection scheme. The alternatives are too numerous to discuss here.

In my opinion, this 2003 edition of NFPA 30 is the finest and most comprehensive edition yet to be published. It belongs in the library of every safety or fire protection engineer.

This article originally appeared in the December 2003 issue of Occupational Health & Safety.