Fogging oil

The life persistency of a smoke cloud is deterrnined chiefly by wind and convection currents in the air. Ambient temperature also plays a part in the continuance or disappearance of fog oil smokes. Water vapor in the air has an important role in the formation of most chemically generated smokes, and high relative humidity improves the performance of these smokes. The water vapor not only exerts effects through hydrolysis, but it also assists the growth of hygroscopic (deliquescent) smoke particles to an effective size by a process of hydration. Smoke may be generated by mechanical, thermal, or chemical means, or by a combination of these processes (7). 

The following are pyrotechnic methods for smoke generation as opposed to mechanical methods such as atomization of fog oil, of Ti tetrachloride (FM smoke) or of S trioxide. This discussion is drawn from Ref 134, which should also be consulted for earlier references ... 

Katz S, Snelson A, Farlow R, et al. 1980. Physical and chemical characterization of fog oil smoke and hexachloroethane smoke. Chicago, IL IIT Research Institute. 

Young JY, Smart DA, Allen JT, et al. 1989. Field exposure of chemical school students and cadre to fog oil and hexachloroethane (HC) smokes. Frederick, MD U S. Army Biomedical Research Development Laboratory. AD-A225-008. 

Army. 1986. Literature survey and data base assessment Microbial fate of diesel fuel and fog oils. Project no. 3E162720A835. Frederick, MD U.S. Army Bioengineering Research and Development Laboratory, Fort Detrick. Document no. PC A03/MFA01. 

Liss-Suter D, Villaume JE, Goldstein FJ. 1978. A literature review - problem definition studies on selected toxic chemicals. Volume 8 Environmental aspects of diesel fuels and fog oils SGF no. 1 and SGF no. 2 and smoke screens generated from them. Philadelphia, PA Franklin Institute Research Laboratories. Final report. Contract no. DAMD 17-77-C-7020. ADAO56021. 

In Alaska, Wilson and others (57) have tested ground aerosol generators for controlling adult mosquitoes. In one test they used 25 gallons of Navy fog oil, 15 gallons of fuel oil, 8 gallons of Velsicol AR-60 (chiefly di- and trimethylnaphthalenes), and 25 pounds of DDT and in another test 5% of DDT in fuel oil. Satisfactory controls were obtained for only a few hours. 

The first of these projects is of especial interest because of the varieties of insects employed as test animals, the number of formulas used, and the principles that were there first demonstrated the latter because it was the first large scale use of a new fog oil developed especially for the work after stud dng and comparing the characteristics and behavior of the formulations used in the Sampson project, and because it was the first instance of fogging from a helicopter. 

Materials and Methods. First Series. The formula used in most of the tests was 10 pounds of DDT in 5 gallons of a solvent which consisted of a mixture of 2 gallons of carbon tetrachloride and 3 gallons of a high-boiling aromatic petroleum solvent (SV PD 544C)—roughly, a 30% DDT solution. The latter was the predecessor of the special fog oil solution, Sovacide F, that was later developed, which in itself possesses certain insecticidal qualities. 

With ground-operated machines, the effects of fogging, while pronounced for a limited time, may be very local as well as temporary, even when a special fog oil is used. A rather spectacular development, but one which appears to have been successful to an unusual degree and to have wide potential usefulness, was the helicopter fogging for blackfly control... 

The chief interest of petroleum chemists in the information presented here may be in the fact that, although the earlier kerosene type of petroleum derivatives mixture will produce insecticide fogs—and is still used successfully for them—an analysis of fog production and its use, from biological, physical, chemical, and mechanical standpoints, has resulted in the evolution of special fog oils which combine higher DDT solvency, specific insecticidal potency, greater safety, and greater chemical and physical stability with consequent limited and therefore more desirable particle size range, at known temperatures and pressures. 

The solvent should be cheap enough so that the advantages of its specific superior qualities as an insecticide fog oil will encourage its production and use. 

Actual tests on a sample of Sovacide F outdoor fog oil, according to data furnished by Socony-Vacuum Laboratories, showed the following characteristics ... 

It is not implied that other effective fog oils have not been devised or used, nor that other fog-producing mechanisms would not achieve the desired results. However, the circumstances and data cited constitute interesting and significant instances of how certain specific insect problems were analyzed, and how, through the coordinated collaboration of engineers, mechanics, chemists, physicists, and entomologists, effective control methods were evolved. 

The latter type usually contains "fog oil which is one of the petroleum oils SGF1 or SGE2 when heated by burning fuel, the "fog oil vaporizes producing dense smoke... 

Mineral oils, including the older preparations of fog oil, can produce cutaneous malignant neoplasms because of the presence of PAHs. In view of this, the military (army) altered the specification for screening smoke fog oil, requiring that it be solvent-treated or hydrotreated to remove potential carcinogenic hydrocarbons and analyzed to confirm the absence of such materials (NRC, 1997). 

Cataldo, D.A., Van Voris, P., Ligotke, M.W., Fellow, R.J., McVeety, B.D., Li, S.W., Bolton, H., Jr., and Frederickson, J.K., Evaluate and characterize mechanisms controlling transport, fate and effects of army smokes in an aerosol wind tunnel transport, transformations, fate and terrestrial ecotoxicological effects of fog oil obscurant smokes. Report Number AD-A20414, Pacilic Northwest Laboratory, Richland, Washington, 1989. 

Liljegren, J.C., Dunn, W.E., DeVauU, G.E., and Policastro, A.J., Field measurement and model evaluation program for the assessment of the environmental effects of Military smokes field study of fog-oil smokes. Report Number AD-A205 344, Argonne National Laboratory, Argonne, IL, 1988. 

Mayhew, D.A., Smith, S.H., Doyle, G.L., Kreuger, J.C., and Mellon, K.A.S., Dermal, eye and oral toxicologic evaluations of brass powder, fog oil, diesel fuel and their mixtures. Report AHJ-A172 198, Bioassay Systems Corporation, Woburn, Massachusetts, 1985. 

Designate supply routes, access routes, fuel resupply points, and/or fuel/fog oil... 

Table 6-4. Fog Oil Consumption (Number of 55-gallon drums) (For general planning M3A4 EM157 ...

When M4 (or Ml) fuel thickening compound is not available, an acceptable alternative fuel can be prepared using a 60% - 40% combination of MO GAS and oil. (NOTE Any kind of oil will work, such as standard 30 weight motor oil, fog oil, or crank case draining.) The best oil to use is 90 weight oil. Example In a... 

Filter exchange criteria (wartime), 3-3 Fire support, D-7—D-10 Flame field expedients 5-gallon flame device, 7-5 bunker bomb, 7-7 checklists, 7-1 flame fougasse, 7-6 minimum safe distances, 7-2 propellant charge fougasse, 7-8 safety, 7-2—7-3 vertical flame mine, 7-1 Fog oil. See Smoke. 

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