Product Information Antimicrobial Agent for Fuel Preservation EPA Reg. No. 464-659 General antimicrobial agent is an excellent preservative for the prevention of microbial growth in hydrocarbons. Studies have shown that at recommended levels it is: effective for shock dosing against bacteria, mold, and yeasts found in contaminated fuels soluble in fuels, hydrocarbons and water at typical use levels active even in the presence of large quantities of water Microbial Contamination When tested at levels of up to 1 ppm in No. 2 diesel fuel, no deleterious effects on engine performance or emissions were noted. Engine rpms, power output, and torque remained unchanged, and no increase in the amount of exhaust pollutants emitted was observed. How Microbial Contamination Affects Fuels Hydrocarbon fuels such as diesel fuel, kerosene, and heating oil are often stored in contact with water. It is not uncommon for a diesel fuel tank to accumulate as much as 1% water (based on the volume of fuel) as a result of condensation during long-term storage. At the water-hydrocarbon interface, conditions are favorable for the growth of microorganisms which often contaminate fuels. Pseudomonads and sulfate-reducing bacteria have been isolated from contaminated fuels, but the greatest sources of problems are fungi, Yarrowia, Cephalosporium, Penicillium and, in particular, Hormoconis resinae and Aspergillus fumigatus. When these organisms are allowed to grow unchecked, they produce long filaments, large mats, or globules which can cling to the surfaces of tank walls, pumps, delivery lines, and vital engine parts. Filters can become clogged, causing poor engine performance or even failure. In addition, as the microorganisms metabolize in the fuel, they produce more water, sludge, and acidic by-products which can corrode metals in contact with the fuel. Heavily contaminated fuel may develop a foul odor, similar to rotten eggs. To demonstrate the efficacy of, a study was conducted at an independent testing laboratory in which was compared with a competitive preservative. Page 1 of 8
Description of the Test was added to No. 2 diesel fuel to produce samples containing concentrations of 135 and 25 ppm of preservative on a volume basis. A similar sample was prepared utilizing a competitive preservative at a 27 ppm level, per the recommendation of the manufacturer. Two hundred and fifty milliliters of each of these treated fuels were placed in separatory funnels. An untreated control sample was also prepared. All samples were then inoculated with 2.5 ml of Bushnell-Haas broth containing microorganisms isolated from various contaminated fuel sources. The initial counts of the inoculum were: Bacteria Mold Yeast 1.6 X 1 6 per ml 6.1 X 1 5 per ml 9.2 X 1 5 per ml All the systems were sampled and analyzed weekly for organism viability over an eight-week period. Results The untreated control supported heavy microbial growth throughout the entire eight-week test period, demonstrating that diesel fuel is an effective nutrient source and needs biocidal protection. In the treated samples, the contaminating microbes (bacteria, mold and yeast) were least affected by the 27 ppm level of the competitive biocide. By contrast, at 25 ppm demonstrated excellent control for the entire eight-week test period, followed by the 135 ppm level which also outperformed 27 ppm of the competitive biocide. Figures 1-3 detail the microbial population counts for the control fuel, the fuel treated with 27 ppm of the competitive biocide and the fuel treated with 135 ppm and 25 ppm. Figure 1 Efficacy vs. Bacteria 1 9 1 8 1 7 Bacteria/mL 1 6 1 5 1 4 1 3 1 2 1 1 2 3 4 5 6 7 8 Time (Weeks) Control 135 ppm 25 ppm Competitive Biocide 27 ppm Page 2 of 8
Figure 2 Efficacy vs. Mold 1 9 1 8 Mold/mL 1 7 1 6 1 5 1 4 1 3 1 2 1 1 2 3 4 5 6 7 8 Time (Weeks) Control 135 ppm 25 ppm Competitive Biocide 27 ppm Figure 3 Efficacy vs. Yeast 1 9 1 8 1 7 Yeast/mL 1 6 1 5 1 4 1 3 1 2 1 1 2 3 4 5 6 7 8 Time (Weeks) Control 135 ppm 25 ppm Competitive Biocide 27 ppm Conclusions will control microbial growth effectively at levels as low as 135 ppm in the fuel. Its ability to provide control is unaffected by the presence of water in the system. In fact, is highly effective for hydrocarbons intentionally stored over water. Protection can be obtained by addition of to the fuel, or by direct addition to the water phase. Fuel/Water Solubility or Partition Coefficient When is added to diesel fuel containing water (1:1 and 1:25), it partitions into both the water and fuel phases. The ratio of in the water phase to that in the fuel phase is.26. This means if 25 ppm of is added to diesel fuel containing water, approximately 65 ppm of will migrate into the water phase. It is the only fuel preservative which is principally fuel-soluble, but which also partitions into the water phase, where microbial growth actually occurs. Biocides which are only fuelsoluble cannot provide protection against growth where it is actually taking place in the water phase. Biocides which are primarily water-soluble may be effective as shock treatments before flushing out contaminated water bottoms; however, these biocides are removed from the system with the water. Only provides a prolonged release of Page 3 of 8
biocidal activity from the fuel phase into the water phase. This means that after contaminated water bottoms have been flushed from a system, is still present to help prevent recontamination. An additional benefit from the use of derives from the fact that most of the actual microbial growth occurs at the fuel-water interface. Here, the phenomenon of invertemulsion formation is often observed. Microbial by-products emulsify the fuel into the water phase. Because of its favorable partition coefficient, can pass from the fuel stage into the water where it can effectively control microbial growth. Efficacy is a very effective shock-dose treatment for contaminated diesel fuel and water bottoms in fuel storage tanks. Because contamination will occur in both the water and fuel phases, it is necessary to demonstrate efficacy in both. No. 2 diesel fuel, stored over water, was challenged with a mixed population of bacteria (Pseudomonas aeruginosa and Desulfovibrio desulfuricans) and fungi (Hormoconis [formerly Cladosporium] resinae and Yarrowia tropicalis). Water and fuel samples were tested to determine microbial loads before and after treatment with. was tested at 125 and 25 ppm (v/v). At 25 ppm, all bacterial contamination was eliminated within one hour and fungal contamination was eliminated in the fuel and water phases within eight hours. All of the test organisms except Yarrowia tropicalis were killed within four hours at the 125 ppm dosage (Figures 4-7). Figure 4 Efficacy (125 ppm) (In Water Phase) 5.x1 6 4.x1 6 3.x1 6 2.x1 6.25.5 1 4 8 24 48 72 Page 4 of 8
Figure 5 Efficacy (25 ppm) (In Water Phase) 5.x1 6 4.x1 6 3.x1 6 2.x1 6.25.5 1 4 8 24 48 72 Figure 6 Efficacy (125 ppm) (In Fuel Phase) 3.5x1 6 3.x1 6 2.5x1 6 2.x1 6 1.5x1 6 5.x1 5.25.5 1 4 8 24 48 72 Figure 7 Efficacy (25 ppm) (In Fuel Phase) 3.5x1 6 3.x1 6 2.5x1 6 2.x1 6 1.5x1 6 5.x1 5.25.5 1 4 8 24 48 72 Page 5 of 8
Persistence-of-Effect Over Water Bottoms A 12-week persistence-of-effect test was run following ASTM E1259-88 (Standard Method for Evaluation of Antimicrobials in Distillate Fuels Based on Preliminary Screening and Compatibility). No. 2 diesel fuel over fresh water was challenged with a mixed population of bacteria (Pseudomonas aeruginosa and Desulfovibrio desulfuricans) and fungi (Hormoconis [formerly Cladosporium] resinae and Yarrowia tropicalis). Water and fuel samples were analyzed to determine microbial loads before treatment and weekly after was added. The results are depicted graphically in Figures 8 and 9., at 125 and 25 ppm, effectively decontaminated the test systems during the first week. It also prevented growth for the duration of the study (12 weeks). Figure 8 Efficacy (125 ppm) Persistence-of- Effect (In Water Phase) 5.x1 6 4.x1 6 3.x1 6 2.x1 6.25 1 2 3 7 14 21 28 35 42 49 56 63 7 77 84 Time (Days) Figure 9 Efficacy (25 ppm) Persistence-of- Effect (In Water Phase) 5.x1 6 4.x1 6 3.x1 6 2.x1 6.25 1 2 3 7 14 21 28 35 42 49 56 63 7 77 84 Time (Days) After 12 weeks, the level of test species in the water phase of untreated controls were >5 X 1 8 (CFU = Colony Forming Units). is an effective quick-kill biocide, as well as a long-term preservative. At a treatment rate of one quart per 1, gallons (25 ppm v/v), kills the bacteria and fungi most often associated with diesel fuel contamination. Page 6 of 8
and Persistence-of-Effect over Seawater Bottoms Contamination not only occurs in storage tanks, but also in the fuel tanks of marine crafts. Seawater in the tanks allows for the propagation of microbial contamination. Recognizing that s performance might be affected by the presence of seawater, the previously described ASTM E1259-88: Standard Method for Evaluation of Antimicrobials in Distillate Fuels, modified by replacing freshwater bottoms with synthetic seawater (Instant Oceans, Aquarium Systems, Sarrebourg, France) was performed. Speed-of-kill data for microbial contaminants in seawater are presented in Figure 1. Bacterial contaminants were virtually eliminated within the first four hours exposure to 25 ppm of. Fungal contaminants were controlled within the first 24 hours after treatment. Figure 1 Efficacy (25 ppm) (Salt Water Phase) 5.x1 6 4.x1 6 3.x1 6 2.x1 6.24.5 1 4 8 24 48 72 168 Persistence-of-effect data are shown graphically in Figure 11. effectively prevented growth of all four test species for three months. Figure 11 Efficacy (25 ppm) Persistence-of- Effect (Salt Water Phase) 1.6x1 6 1.4x1 6 1.2x1 6 8.x1 5 6.x1 5 4.x1 5 2.x1 5 1 2 3 4 5 6 7 8 9 1 11 12 Time (Weeks) is as effective in fuel systems containing seawater bottoms as it is in systems containing freshwater bottoms. At a treatment rate of one quart per 1, gallons Page 7 of 8
(25 ppm v/v), kills the bacteria and fungi most commonly recovered from contaminated fuel systems. Using Addition Levels may be added to fuel or water bottoms to achieve levels up to 1 ppm by weight. Direct addition to fuel or water bottoms may be accomplished by slug dosage or metering. To facilitate mixing with the water bottoms, it may be useful to predilute in water or a water-coupling agent mixture such as tripropylene glycol monomethylether. Volume to Get Dose: Fuel Volume (ppm) (gallons) 135 25 5 1 1.17 fl. oz..32 fl. oz..64 fl. oz. 1.28 fl.oz. 1 1.7 3.2 6.4 12.8 1 17 32 64 128 Volume to Get Dose: Fuel Volume (ppm) (liters) 135 25 5 1 1 13.5 mls 25 mls 5 mls 1 mls 1 135 mls 25 mls 5 mls 1. liter 5 675 mls 1.25 liters 2.5 liters 5 liters Complete instructions on the safe handling and the use of are given in DOW Technical Information Sheet No. 253-126. For further information visit our website: www.dowbiocides.com or call United States 1-8-447-4369 (phone) and Canada: 1-989-832-156 (phone) 1-989-832-1465 (fax) Europe: 8-3-694-6367 (phone) 32-3-45-224 (phone) Pacific: 32-3-45-2815 (fax) 63-7958-3392 (phone) 63-7958-5598 (fax) Latin America: 55-11-5188-9555 (phone) 55-11-5188-9937 (fax) Other Global 1-989-832-156 (phone) Areas: 1-989-832-1465 (fax) NOTICE: No freedom from any patent owned by Seller or others is to be inferred. Because use conditions and applicable laws may differ from one location to another and may change with time, Customer is responsible for determining whether products and the information in this document are appropriate for Customer s use and for ensuring that Customer s workplace and disposal practices are in compliance with applicable laws and other governmental enactments. Seller assumes no obligation or liability for the information in this document. NO WARRANTIES ARE GIVEN; ALL IMPLIED WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ARE EXPRESSLY EXCLUDED. Page 8 of 8 Printed in U.S.A. *Trademark of The Dow Chemical Company