BY A.K. ROSENHAN
Pig fat and soybean oil sound like a bad diet. But given the price of diesel fuel these days, such a combination is becoming more and more common as the economics of so-called alternative fuels change.
Several types of alternative fuels are becoming quite common, and their manufacture and storage pose some new challenges and hazards for the fire service and necessitate the implementation of specialized firefighting/hazmat operations. One alternative involves the production of ethanol in a complicated process that involves a number of potentially hazardous operations and intermediate materials. In addition, the finished product poses a significant fire and safety hazard. Although there are several methods of producing biodiesels, they usually involve very simple chemical processes, with relatively little hazard involved, and the final product is less flammable than diesel fuel. However, the chemicals involved present potential problems. Small backyard biodiesel operations are springing up all over the country, usually with no involvement by local code agencies, fire departments, or any sort of permitting/review.
INCIDENTS
A September 29, 2008, fire in the Yakima, Washington, area destroyed a large garage containing a biodiesel manufacturing facility. The production equipment was not rated for use in a hazardous location. Another such fire recently occurred in the same area and resulted in a serious burn injury to a worker. The manufacturing system in use was not code compliant.1
(1-2) General view of process equipment/apparatus. Note the use of plastic tankage. (Photos by author.) 
Another such incident occurred in Clackamas County, Oregon, where firefighters responding to a garage fire in a rural area found it wasn’t an ordinary fire but one that generated a lot of black smoke, was very hot, and was hard to extinguish. This fire involved some 500 gallons of biodiesel stored in plastic tanks; a nearby tank containing 300 gallons of methanol was saved.2
In Portland, Oregon, a fire destroyed a startup biodiesel company. The Oregon Department of Environmental Quality commented that no regulations cover biodiesel operations as they might relate to being a hazardous material or waste.3 Many jurisdictions, especially those in rural areas, simply do not have codes, regulations, inspections, or other resources to ensure safe operations and overall public safety.
There is a good chance the responding fire department will be faced with numerous tanks, pipes, and pumps without any labels or data that describe their contents. Further, there will be exposures to deal with, as well as the probability of hazardous runoff from fire damage and firefighting operations.
PRODUCTION FACILITIES
The production facility of biodiesels is classified as an industrial organic chemical facility that uses transesterification of various vegetable oils and animal fats to produce biodiesel. In 40 CFR Part 60, Standard of Performance for New Stationary Sources (NSPS), Subpart VV—“Standards of Performance for Equipment Leaks of VOC in the Synthetic Organic Chemical Manufacturing Industry for which Construction, Reconstruction, or Modification Commenced After January 5, 1981, and on or Before November 7, 2006,” the production configuration is defined as “a synthetic organic chemicals manufacturing facility.” Biodiesel is technically a “fatty-acid methyl ester” and may be made from a variety of raw materials such as animal fat (swine, chicken, bovine) and vegetable oils (soybean, cottonseed, sunflower, castor, peanut, and others). Further, some operations use waste oil and fat from food-frying facilities and other sources.
Such facilities conform to the definition of a chemical plant, which is defined as “an integrated plant” in Chapter 1 of National Fire Protection Association (NFPA) 30, Flammable and Combustible Liquids Code, 2000 edition (the version in effect in this community at the time of construction), as “other than a refinery or distillery, where liquids are produced by chemical reactions or used in chemical reactions.” There are comparable definitions in various other fire and building code standards.
The process and the materials involved are not hazardous except for the storage of methanol and sodium methylate, both process ingredients that are normally reclaimed. The basic materials to be delivered, processed, and stored at such a facility include the following:
- Soybean oil: a class IIIB liquid, unrated by NFPA; flash point greater than 550°F.
- Sodium methylate (methoxide): Chemical Abstract Service (CAS), division of the American Chemical Society, #124-41-4. This is a fire hazard, and no water should be employed in a fire situation. There are various strengths of this mixture with methanol. Less than 24 percent in any process flow is not considered an ignitable hazardous mixture. Decomposition in air temperature is 300°F, flash temperature 52°F, Class IB. Reaction residue nonhazardous. This material can explode and is a nerve agent.
- Methanol: a flammable liquid (flash point 55°F), CAS # 67-56-1, a class IB liquid, soluble in water, usually a large quantity (thousands of gallons) is present.
- Biodiesel: CAS # 67784-80-9, contains no hazardous material, is a Class IIIB liquid; flash point 425°F, and is treated as an oil fire if ignited; storage facilities same as for diesel fuel.
- Vegetable glycerin: CAS # 56-81-5, no percent hazardous, Class IIIB liquid, flash point 390°F, a by-product of the biodiesel process with large quantities typically on premises.
- Sulfuric acid: CAS #7664-93-9, flash point not applicable, usually small quantities in facility.
- Tallow/animal fat: no vapor density or hazard, Class IIIB material, flash temperature over 600°F, various quantities on premises dependent on supply economics.
- Sodium hydroxide: CAS #95077-05-7, a corrosive, strong alkaline, caustic material; water reactive; produces an exothermic reaction when mixed with water and can ignite surrounding combustibles. Use Guide 154 in the ERG ID #1823 and 1824. Don’t get it on you. Hopefully, a relatively small amount of this material is in the typical installation, and it will be properly labeled.
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| (3) Large-volume storage of methanol used in processing. Fire codes dictate size, location, clearance, and drainage considerations. Note: Firefighting foam must be compatible with methanol. 2008 Emergency Response Guidebook (ERG), U.S. Department of Transportation, Guide 131, ID #1230. |
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| (4) An unusual material in quantity. Use ERG Guide 138, ID #1431. |
Reference is made to NFPA 30 (2000 edition) Section 2.3.2 “Installation of Above Ground Tanks,” to evaluate the storage tank layout, quantity stored, and fire protection for a facility. Figure 1 shows the site’s typical storage tank layout plan. Table 1 presents data relating to the capacity and spacing from NFPA 30 Table 2.3.2.1.1(b) for tanks not having more than a 2.5 pounds per square inch gauge (psig) storage pressure.
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| Figure 1. Biodiesel Production Site |
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POLLUTION PREVENTION PLAN
You must create a Storm Water Pollution Prevention Plan for a facility that covers overall site drainage from rainwater and runoff. Include in the report ground- and air-pollution emission material related to state and federal regulations and maps and diagrams relating to drainage from storm water, leaks, and process effluent (if any).
In addition to diking and impoundment around each liquid storage tank, there must be a curb around the entire production area to impound any runoff from any source. This low curb, coupled with the dimensions of the concrete slab on which all production equipment and storage tanks are located, must be more than sufficient in containment volume to contain any possible spill of process liquid. A separate pump and separate spill tank will always be available for collection of any spilled material as directed by authorities.
FIRE PROTECTION
Facility fire protection is defined in NFPA 30 and NFPA 10, Standard for Portable Fire Extinguishers. Given the physical and chemical properties of the materials contained in the processing building, a Class B type of fire extinguishing agent, dry chemical, is to be employed. All such portable fire extinguishers are to be Underwriters Laboratories-rated, inspected annually, and located properly. Employees must be trained in how to operate each type and size of extinguisher. The processing building is classified as Extra Hazard Occupancy, per NFPA 10, with the extinguisher requirement from tables in NFPA 10.
Although biodiesel poses less of a fire hazard than typical diesel fuel (flash point of around 300°F compared with 125°F for diesel), a responding fire department must be prepared for the typical pool fire scenario and have adequate Class B foam to control a spill or a leak. More importantly, the presence of methanol requires Class B alcohol-resistant concentrate (ARC) foams, something that many fire departments are not familiar with and do not have available.
Whether the installation is a home-built, small-storage and small-capacity operation or a large, commercial venture with thousands of gallons of material, a fire department must be prepared for the type of fuel, equipment configuration, and runoff such hazards present. A good preplan, the same as for any industrial/chemical installation, is necessary to ensure that any incident will be handled effectively, quickly, and—most importantly—safely. Increased diligence is needed to ensure that responders have an idea of what to look for and how to react when they encounter an unexpected biodiesel operation.
Endnotes
1. “Biodiesel Fires,” Washington Fire Chiefs Web site, September 29, 2008, http://www.wsafc.org/?deptid=1&com=news&pressID=1944/.
2. “Major Fire Erupts at Biodiesel Manufacturing Site,” Salem-News.com, June 24, 2006, http://www.salem-news.com/articles/june242006/biodiesel_fire_62406.php/.
3. Redden, Jim, “Fire puts biodiesel under scrutiny,” The Portland Tribune, July 7, 2006, http://www.portlandtribune.com/news/story.php?story_id=115223036291292200/.
4. 2008 Emergency Response Guidebook, U.S. Department of Transportation.
A.K. ROSENHAN, PE, CEng, CFO, MIFireE, is the fire services coordinator for Oktibbeha County, Mississippi. A registered fire protection engineer, he is active with the Institution of Fire Engineers (UK), the National Fire Protection Association, and the Society of Fire Protection Engineers.
