Working at the U.S. Department of Agriculture as part of the World War II effort, two scientists developed a portable aerosol spray container for insecticides such as DDT. Spray cans came to be used for an endless variety of consumer products, not only insecticides but also beauty and grooming products, foodstuffs, household cleaners, and paints.

Humankind has always been plagued by a variety of creatures harmful to its existence. Viruses, bacteria, fungi, insects, and other invertebrate and vertebrate animals attack humans and the plant and animal species on which they depend for survival. Innumerable measures have been tried to counter these attacks, including pesticides Pesticides to kill various creatures or otherwise render them harmless. No single substance exists to ward off all types of destructive agents, so a variety of substances have been designed for specific adversaries. Insecticides to prevent insects from carrying diseases to humans and livestock and to prevent plant crop destruction are perhaps the best-known and most widely used pesticides. Pesticides also include fungicides to inhibit fungus growth, herbicides to eradicate unwanted plants (weeds), bactericides to destroy harmful bacteria, and rodenticides to kill small mammals. Aerosol spray containers, portable
Insecticides;aerosol spray
Pesticides
[kw]Portable Aerosol Containers Are Introduced (1941)
[kw]Aerosol Containers Are Introduced, Portable (1941)
Aerosol spray containers, portable
Insecticides;aerosol spray
Pesticides
[g]North America;1941: Portable Aerosol Containers Are Introduced[00050]
[g]United States;1941: Portable Aerosol Containers Are Introduced[00050]
[c]Inventions;1941: Portable Aerosol Containers Are Introduced[00050]
[c]Science and technology;1941: Portable Aerosol Containers Are Introduced[00050]
[c]World War II;1941: Portable Aerosol Containers Are Introduced[00050]
[c]Manufacturing and industry;1941: Portable Aerosol Containers Are Introduced[00050]
Goodhue, Lyle D.
Sullivan, William N.
Wickard, Claude R.

In the early part of the twentieth century, inorganic poisons were widely used as insecticides. Copper, lead, and arsenic compounds, however, killed not only insects but, if used in excess, humans as well. With the start of World War II, these elements were needed for the war effort, and alternative insecticides Insecticides;synthetic poisons
Pesticides derived from plant sources or produced synthetically began to be used. Nicotine, extracted from tobacco plants, and pyrethrum, derived from a type of chrysanthemum flower, had long been known to be effective.

One of the best-known synthetic insecticides was dichloro-diphenyl-trichloroethane Dichloro-diphenyl-trichloroethane[Dichlorodiphenyl trichloroethane] (DDT). The extensive use of DDT and other chlorine-containing hydrocarbons was extremely effective in the battle against infective insects. DDT was, for example, successful in significantly reducing malaria in tropical countries by controlling the mosquito that carries the disease. Without this, the Pacific campaign during World War II would have been much more difficult. Not until years later did the harmful effects of long-term exposure to DDT, which builds up in animal tissues, become widely realized. Use of DDT was officially banned in the United States in 1972.

Because the effectiveness of a fighting force is hampered by disease and infection, the U.S. Department of Agriculture Department of Agriculture, U.S. , as a part of the war effort, launched various studies aimed at developing more effective insecticides World War II (1939-1945)[World War 02];insecticide research during . The studies addressed improved purification methods for naturally occurring insecticides, synthesis and testing of alternate insecticides, and improved methods of insecticide dispersion. At the time, insecticides were dispersed as solids, as dusts affixed to fine, inert carrier particles, and in sprays using compressed air and some form of propellant. Liquid propellant, often water, transported the insecticide in solution, or—because many insecticides were insoluble in the carrier liquid—as an emulsion.

To achieve maximum effectiveness, an insecticide had to be dispersed as widely as possible. Solids therefore had to be in the form of fine powders, and liquids had to be fine sprays, generally a mist or fog. One way to create a fine mist was to direct the liquid carrier with its concentration of insecticide against a heated surface such as a hot plate; this procedure, although effective in dispersing an insecticide, was inconvenient, because it required a heated surface, and the apparatus was not portable and could not be readily used in the field. Chemist Lyle D. Goodhue and entomologist William N. Sullivan were among those in the Department of Agriculture’s Bureau of Entomology and Plant Quarantine Bureau of Entomology and Plant Quarantine, U.S. who developed a portable apparatus for rapid and effective dispersion of an insecticide spray.

An aerosol is a solution containing finely divided liquid or solid particles distributed uniformly in a gas. The aerosol container developed by Goodhue and Sullivan consisted of a heavy walled canister whose opening at the top was in the form of a nozzle with a small orifice. A long tube inside the canister ran from the nozzle to near its bottom. When partially filled with a volatile liquid, pressure built up inside the canister from the liquid vapor pressure at the top. On opening the orifice, this pressure pushing down on the liquid below forced the liquid up the tube and through the opening as a fine mist or spray. If the confined liquid contained the dissolved or emulsified insecticide, the insecticide was sprayed into the air and reached into cracks, corners, and crevices where insects normally hide.

The unit was both effective and portable. Developed in 1941, the apparatus was presented at the American Chemical Society meeting and in printed form in the journal Industrial and Engineering Chemistry. The significance of this device was immediately realized by the Armed Forces as a means of controlling lice, flies, disease-carrying mosquitoes, and other pests. “Each dispenser . . . loaded with one pound of a liquid insecticide . . . in twelve to fourteen minutes . . . will fumigate 150,000 cubic feet of space, the equivalent of 240 army pup tents or fifty giant bombers,” reported The New York Times on March 14, 1943. The paper referred to the device as a “health bomb.”

This image of aerosol cans containing the insecticide permethrin appears in a U.S. Army training manual. Aerosol insecticides remain important military equipment.

(Armed Forces Pest Management Board)

Work on increasing the aerosol spray’s effectiveness continued for some time after its introduction. When first tested, methyl chloride (CH3C1) and dichlorodifluoromethane (CC12F2) were used as the volatile liquids, and pyrethrum was the insecticide dispersed. A small amount of sesame oil had been added; it acted as a synergist, a component that itself has no insecticidal properties but when present greatly increases the effectiveness of the insecticide. Goodhue and colleagues studied a number of such synergistic substances for their optimum concentrations. Other factors in a spray’s effectiveness were the types of volatile liquid, insecticide, and synergist; concentration of and possible interaction between insecticide and synergist; the insecticide’s solubility; possible reaction of the insecticide or synergist with the container and degradation during storage; and particle size of the spray, which depends in part on the size of the nozzle orifice. All these variables were studied at the Department of Agriculture, resulting in a number of scientific papers, as well as patents; all patents pertaining to the aerosol development were issued on behalf of the secretary of agriculture, Claude R. Wickard, so they could not result in personal gain for those working on the projects.

Goodhue and Sullivan in 1945 were jointly awarded the John Scott Medal, an award sponsored by the city of Philadelphia from a bequest by John Scott for significant scientific contributions that benefit humankind. The award consisted of a medal and one thousand dollars, which was divided equally between the recipients.

A portable, effective insecticide spray was enormously important for maintaining a healthy and disease-free fighting force during World War II. After the war ended in 1945, aerosol spray containers began to be used both industrially and commercially. Advertisements at the time pointed to the merits of these portable sprayers for ridding homes of all varieties of insect pests, and the term “bug bomb” came into use.

Aerosol sprays soon began to be adapted for dispensing components other than insecticides. By the early 1950’s, more than thirty million aerosol canisters containing everything from health care products (for example, deodorants, shampoos, and suntan lotions) to foodstuffs had appeared on retail shelves. Automobile products in the form of aerosol sprays included deicers, chrome protector sprays, ignition drier fluid, and touch-up paint. For home use there were window cleaners, furniture waxes, paints, and fire extinguishers. By 1956, sales of products in aerosol containers totaled $390 million, the equivalent, as Science Digest reported, of “117 billion 1-second pffts or about 700 squirts for everyone in the U.S.”

Different products often necessitated modifications in the components and assembly of aerosol sprays. Shaving cream or pancake batter, for example, required a carrier fluid of higher vapor pressure to force the heavier substance from the container and a larger nozzle orifice. For foodstuffs, carrier fluids and synergistic agents were particularly restricted. Components of the canister itself had to be chosen to be nonreactive with the contents and of sufficient strength for the pressure chosen.

Many of the components that were initially used in aerosol sprays gradually became prohibited as their injurious effects either on humans or on the environment became known. Dichloro-diphenyl-trichloroethane, or Freon 12, was one of the carrier fluids first used by Goodhue and Sullivan. Freons Freons and Earth’s environment , a large class of gaseous, liquid, and solid compounds containing chlorine- and fluorine-carbon, were shown to interfere with the earth’s ozone layer and are no longer used in aerosol sprays. They were replaced by less offensive or inert carriers. Many of the insecticides initially used for insect control were also discontinued. DDT, once championed for its control of various disease-bearing insects, was banned in the United States in 1972, although it continued to be used elsewhere in the world. Exposure limits for various insecticides were often set by the U.S. federal government, with a phaseout clause allowing existing supplies to be used. Alternate substances used to control insects included biological agents (natural predators to harmful species), pheromones (sex attractants to lure insects into traps), and genetic engineering to alter the internal makeup of a species and prevent its reproduction. Many of these substances, too, were dispensed with aerosol sprays. Uses of aerosol containers eventually, however, extended far beyond the initial “bug bomb” developed by Goodhue and Sullivan. Aerosol spray containers, portable
Insecticides;aerosol spray
Pesticides

• Bartlett, Arthur. “Chemical Marvels Take the ’Bug’ Out of Living.” Popular Science 146 (May, 1946): 150-154. Reports on the aerosol insecticide spray becoming available for home use after the close of World War II.
• Dowswell, Paul. Great Inventions, Everyday Life. Chicago: Heinemann Library, 2002. Two-page descriptions of inventions of common objects, including the spray can. Includes images and a brief history of the spray can’s development.
• Gallager, Sheldon M. “You Wouldn’t Know the Old Bug Bomb.” Popular Science 157 (December, 1950): 102-106. Reports on the expanded use of aerosol spray containers for a variety of products ranging from shampoos to whipped cream.
• Goodhue, Lyle D. “Insecticidal Aerosol Production.” Industrial and Engineering Chemistry 34 (December, 1942): 1456-1459. Technical report that describes the dispensing of an insecticide in a container as an aerosol spray.
• Goodhue, Lyle D., and E. R. McGovran. “Liquefied-Gas Method of Producing Germicidal Aerosols.” Science 99 (June 23, 1944): 511-512. Describes in general terms how the aerosol spray container was developed.
• “On the Bug Front.” Time 39 (April 20, 1942): 44-45. Reports on the development of new insecticides to protect soldiers fighting in World War II.
• Rasmussen, Nicolas. “Plant Hormones in War and Peace: Science, Industry, and Government in the Development of Herbicides in 1940’s America.” Isis 92 (2001): 291-316. Through an analysis of the role of science, industry, and government in the war efforts of the 1940’s, places the development of aerosol containers, and herbicides especially, in historical context. Also examines the postwar marketing of these chemicals for lawn treatments and other general consumer uses.
• Slocum, Ken. “New Magic with Pushbutton Sprays.” Science Digest 42 (December, 1957): 23-26. Reports on the rapid growth of aerosol sprays for a wide variety of products.
• Spurney, Kvetoslav R., and Dieter Hochrainer, eds. Aerosol Chemical Processes in the Environment. Boca Raton, Fla.: Lewis, 2000. An extensive, if technical and specialized, overview. See, especially, chapter 1, “Aerosol Chemistry and Its Environmental Effects.”
• Wharton, James. Before “Silent Spring.” Princeton, N.J.: Princeton University Press, 1974. Discusses the recognition of insect problems and regulations in force prior to 1962. Also includes a history of pesticides and public health. Contains bibliographic notes by chapter and an index. Meant as a source of information for the adult reader.

First Modern Herbicide Is Introduced

Fluoride Is Introduced into the U.S. Water Supply

Dioxin Causes Chloracne in West German Chemical Workers

Congress Sets Standards for Chemical Additives in Food

United States Sprays Agent Orange in Vietnam

Carson Publishes Silent Spring

Jensen Finds PCBs in Animal Tissues

Pesticide Poisons the Rhine River

DDT Ban Signals New Environmental Awareness

Environmental Protection Agency Is Created