Styrofoam is a

trademark A trademark (also written trade mark or trade-mark) is a type of intellectual property consisting of a recognizable sign, design, or expression that identifies products or services from a particular source and distinguishes them from ot ...

ed brand of closed-cell extruded polystyrene foam (XPS), commonly called "Blue Board", manufactured as foam continuous

building insulation Building insulation is any object in a building used as insulation for thermal management. While the majority of insulation in buildings is for thermal purposes, the term also applies to acoustic insulation, fire insulation, and impact ins ...

board used in walls, roofs, and foundations as

thermal insulation Thermal insulation is the reduction of heat transfer (i.e., the transfer of thermal energy between objects of differing temperature) between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with ...

and water barrier. This material is light blue in color and is owned and manufactured by

DuPont DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in ...

. DuPont also has produced a line of green and white foam shapes for use in crafts and floral arrangements. ''Styrofoam'' is colloquially used worldwide to refer to another material that is usually white in color and made of expanded (not extruded)

polystyrene foam Polystyrene (PS) is a synthetic polymer made from monomers of the aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin per unit weight. It is ...

( EPS). It is often used in food containers, coffee cups, and as

cushioning Package cushioning is used to protect items during shipment. Vibration and impact shock during shipment and loading/unloading are controlled by cushioning to reduce the chance of product damage. Cushioning is usually inside a shipping container s ...

material in

packaging Packaging is the science, art and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of designing, evaluating, and producing packages. Packaging can be described as a c ...

. The trademarked term is used generically although it is a different material from the extruded polystyrene used for Styrofoam insulation. Additionally, it is moderately soluble in many organic solvents,

cyanoacrylate Cyanoacrylates are a family of strong fast-acting adhesives with industrial, medical, and household uses. They are derived from ethyl cyanoacrylate and related esters. The cyanoacrylate group in the monomer rapidly polymerizes in the presence ...

, and the propellants and solvents of

spray paint Aerosol paint (commonly spray paint) is paint that comes in a sealed, pressurized container and is released in an aerosol spray when a valve button is depressed. Aerosol painting is one form of spray painting; it leaves a smooth, even coat, unli ...

History

In the 1940s, researchers, originally at Dow's Chemical Physics Lab, led by

Ray McIntire Otis Ray McIntire (24August 19182February 1996) was an American engineer. After graduating from the University of Kansas with a BSc degree in engineering in 1940, he went to work as a research engineer for The Dow Chemical Company. During World ...

, found a way to make foamed

polystyrene Polystyrene (PS) is a synthetic polymer made from monomers of the Aromatic hydrocarbon, aromatic hydrocarbon styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and brittle. It is an inexpensive resin pe ...

. They rediscovered a method first used by Swedish inventor

Carl Georg Munters Carl Georg Munters (22 March 1897 – 1989) was a Swedish inventor, most known for inventing together with Baltzar von Platen the gas absorption refrigerator now sold by Electrolux. He also invented and patented a method of making foamed plas ...

, and obtained an exclusive license to Munters's

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an enabling disclosure of the invention."A ...

in the United States. Dow found ways to adapt Munters's method to make large quantities of extruded polystyrene as a closed cell foam that resists moisture. The patent on this adaptation was filed in 1947.

Uses

Styrofoam has a variety of uses. Styrofoam is composed of 98% air, making it lightweight and buoyant. DuPont produces Styrofoam building materials, including varieties of

sheathing and pipe insulation. The claimed R-value of Styrofoam insulation is five per inch. Styrofoam can be used under roads and other structures to prevent soil disturbances due to freezing and thawing. DuPont also produces Styrofoam blocks and other shapes for use by

florist Floristry is the production, commerce, and trade in flowers. It encompasses flower care and handling, floral design and arrangement, merchandising, production, display and flower delivery. Wholesale florists sell bulk flowers and related su ...

s and in craft products. DuPont insulation Styrofoam has a distinctive blue color; Styrofoam for craft applications is available in white and green.

Environmental issues

The

EPA The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...

and

International Agency for Research on Cancer The International Agency for Research on Cancer (IARC; french: Centre International de Recherche sur le Cancer, CIRC) is an intergovernmental agency forming part of the World Health Organization of the United Nations. Its role is to conduct and ...

reported limited evidence that styrene is

carcinogen A carcinogen is any substance, radionuclide, or radiation that promotes carcinogenesis (the formation of cancer). This may be due to the ability to damage the genome or to the disruption of cellular metabolic processes. Several radioactive sub ...

ic for humans and

experimental animal Animal testing, also known as animal experimentation, animal research, and ''in vivo'' testing, is the use of non-human animals in experiments that seek to control the variables that affect the behavior or biological system under study. This ...

s, meaning that there is a positive association between exposure and cancer and that causality is credible, but that other explanations cannot be confidently excluded. See also the expansive list of environmental issues of Polystyrene, among those it being non-biodegradable.

References

External links

{{sisterlinks, c=Extruded polystyrene, d=Q1194725, s=no, b=no, q=no, n=no, v=no, voy=no, m=no, mw=no, species=no
Bio-Styrofoam from cellulosic crystals, better insulator than styrofoam and supports 200 times its weight
Dow Chemical Company Foams Plastic brands Brand name materials Brands that became generic Building insulation materials Organic polymers Swedish inventions 1941 in technology Products introduced in 1941 American inventions