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Styrofoam brand insulation extruded polystyrene foam (XPS), owned and manufactured by Dow Styrofoam Insulation.jpg
Styrofoam brand insulation extruded polystyrene foam (XPS), owned and manufactured by Dow

Styrofoam is a trademarked brand of closed-cell extruded polystyrene foam (XPS), commonly called "Blue Board", manufactured as foam continuous building insulation board used in walls, roofs, and foundations as thermal insulation and water barrier. This material is light blue in color and is owned and manufactured by The Dow Chemical Company. [1]


Styrofoam is colloquially used worldwide to refer to another material that is usually white in color and made of expanded (not extruded) polystyrene foam (EPS). [2] It is often used in food containers, coffee cups, and as cushioning material in packaging. [1] The trademarked term is used generically although it is a different material from the extruded polystyrene used for Styrofoam insulation. [2]

The Styrofoam brand polystyrene foam, which is used for craft applications, can be identified by its roughness and the "crunch" it makes when cut. Additionally, it is moderately soluble in many organic solvents, cyanoacrylate, and the propellants and solvents of spray paint.


In the 1940s, researchers in Dow's Chemical Physics Lab, led by Ray McIntire, found a way to make foamed polystyrene. They rediscovered a method first used by Swedish inventor Carl Georg Munters, and obtained an exclusive license to Munters's patent in the United States. [3] 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. [4]


Styrofoam has a variety of uses. Styrofoam is composed of 98% air, making it lightweight and buoyant. [5]

Dow produces Styrofoam building materials, including varieties of building insulation sheathing and pipe insulation. The claimed R-value of Styrofoam insulation is five per inch. [6]

Styrofoam can be used under roads and other structures to prevent soil disturbances due to freezing and thawing. [7] [8]

Dow also produces Styrofoam as structural insulated panels for use by florists and in craft products. [9] Dow insulation Styrofoam has a distinctive blue color; Styrofoam for craft applications is available in white and green.

Environmental effects

The EPA and International Agency for Research on Cancer reported limited evidence that styrene is carcinogenic for humans and experimental animals, meaning that there is a positive association between exposure and cancer and that causality is credible, but that other explanations cannot be confidently excluded. [10] [11]

See also

Related Research Articles

Thermal insulation Minimization of heat transfer

Thermal insulation is the reduction of heat transfer between objects in thermal contact or in range of radiative influence. Thermal insulation can be achieved with specially engineered methods or processes, as well as with suitable object shapes and materials.

Polystyrene Polymer

Polystyrene (PS) is a synthetic aromatic hydrocarbon polymer made from the monomer known as styrene. Polystyrene can be solid or foamed. General-purpose polystyrene is clear, hard, and rather brittle. It is an inexpensive resin per unit weight. It is a rather poor barrier to oxygen and water vapour and has a relatively low melting point. Polystyrene is one of the most widely used plastics, the scale of its production being several million tonnes per year. Polystyrene can be naturally transparent, but can be coloured with colourants. Uses include protective packaging, containers, lids, bottles, trays, tumblers, disposable cutlery and in the making of models.

Thermoplastic Plastic that becomes soft when heated and hard when cooled

A thermoplastic, or thermosoftening plastic, is a plastic polymer material that becomes pliable or moldable at a certain elevated temperature and solidifies upon cooling.

Structural insulated panel

A structural insulated panel, or structural insulating panel, (SIP), is a form of sandwich panel used in the construction industry.

Insulating concrete form

Insulating concrete form or insulated concrete form (ICF) is a system of formwork for reinforced concrete usually made with a rigid thermal insulation that stays in place as a permanent interior and exterior substrate for walls, floors, and roofs. The forms are interlocking modular units that are dry-stacked and filled with concrete. The units lock together somewhat like Lego bricks and create a form for the structural walls or floors of a building. ICF construction has become commonplace for both low rise commercial and high performance residential construction as more stringent energy efficiency and natural disaster resistant building codes are adopted.

Polystyrene may refer to:

Coffee cup Tableware product

A coffee cup is a container that coffee and espresso-based drinks are served in. Coffee cups are typically made of glazed ceramic, and have a single handle for portability while the beverage is hot. Ceramic construction allows a beverage to be drunk while hot, providing insulation to the beverage, and quickly washed with cold water without fear of breakage, compared to typical glassware.

Polyisocyanurate Type of plastic typically used for thermal insulation

Polyisocyanurate, also referred to as PIR, polyiso, or ISO, is a thermoset plastic typically produced as a foam and used as rigid thermal insulation. The starting materials are similar to those used in polyurethane (PUR) except that the proportion of methylene diphenyl diisocyanate (MDI) is higher and a polyester-derived polyol is used in the reaction instead of a polyether polyol. The resulting chemical structure is significantly different, with the isocyanate groups on the MDI trimerising to form isocyanurate groups which the polyols link together, giving a complex polymeric structure.

Carl Munters

Carl Georg Munters 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 plastic, which was later rediscovered by Dow Chemical Company and used to make Styrofoam.

Hexabromocyclododecane Chemical compound

Hexabromocyclododecane is a brominated flame retardant. It consists of twelve carbon, eighteen hydrogen, and six bromine atoms tied to the ring. Its primary application is in extruded (XPS) and expanded (EPS) polystyrene foam that is used as thermal insulation in the building industry. Other uses are upholstered furniture, automobile interior textiles, car cushions and insulation blocks in trucks, packaging material, video cassette recorder housing and electric and electronic equipment. According to UNEP, "HBCD is produced in China, Europe, Japan, and the USA. The known current annual production is approximately 28,000 tonnes per year. The main share of the market volume is used in Europe and China". Due to its persistence, toxicity, and ecotoxicity, the Stockholm Convention on Persistent Organic Pollutants decided in May 2013 to list hexabromocyclododecane in Annex A to the Convention with specific exemptions for production and use in expanded polystyrene and extruded polystyrene in buildings. Because HBCD has 16 possible stereo-isomers with different biological activities, the substance poses a difficult problem for manufacture and regulation.

Building insulation materials

Building insulation materials are the building materials which form the thermal envelope of a building or otherwise reduce heat transfer.

Insulated shipping containers are a type of packaging used to ship temperature sensitive products such as foods, pharmaceuticals, organs, blood, biologic materials, vaccines and chemicals. They are used as part of a cold chain to help maintain product freshness and efficacy. The term can also refer to insulated intermodal containers or insulated swap bodies.

Foam food container

A foam food container is a form of disposable food packaging for various foods and beverages, such as processed instant noodles, raw meat from supermarkets, ice cream from ice cream parlors, cooked food from delicatessens or food stalls, or beverages like "coffee to go". They are also commonly used to serve takeout food from restaurants, and are also available by request for diners who wish to take home the remainder of their meal. The foam is a good thermal insulator, making the container easy to carry as well as keeping the food at the temperature it had when filled into the container, whether hot or cold.

Rigid panel

Rigid panel insulation, also referred to as continuous insulation, can be made from foam plastics such as polyurethane (PUR), polyisocyanurate (PIR), and polystyrene, or from fibrous materials such as fiberglass, rock and slag wool. Rigid panel continuous insulation is often used to provide a thermal break in the building envelope, thus reducing thermal bridging.

Otis Ray McIntire 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 War II, when rubber was in short supply, McIntire's work focused on developing a rubber-like substance that could be used as a flexible insulator. In an experiment, in which he combined styrene with isobutylene, he created a unique material that was solid yet flexible due to the tiny bubbles formed by isobutylene within the styrene.

Insulated siding is home siding that includes rigid foam insulation, fused behind the exterior surface of the wall, for the purpose of reducing energy consumption, increasing the insulation value of the wall system and improving the stability and appearance of the siding. Currently, insulated siding is commercially available as a type of vinyl siding.


Geofoam is expanded polystyrene (EPS) or extruded polystyrene (XPS) manufactured into large lightweight blocks. The blocks vary in size but are often 2 m × 0.75 m × 0.75 m. The primary function of geofoam is to provide a lightweight void fill below a highway, bridge approach, embankment or parking lot. EPS Geofoam minimizes settlement on underground utilities. Geofoam is also used in much broader applications, including lightweight fill, green roof fill, compressible inclusions, thermal insulation, and drainage.

Polymeric foam

A polymeric foam is a foam, in liquid or solidified form, formed from polymers.

Styrofoam is a brand of insulation made from extruded polystyrene foam.

Sylvia Stoesser American chemist

Sylvia Marie Stoesser, was an American chemist. She was the first woman to be employed as a chemist at Dow Chemical Company. During her time at Dow, she made a number of major contributions, holding more than two dozen patents as a result of her research.


  1. 1 2 "What is STYROFOAM?". March 24, 2008. Archived from the original on 2008-03-24.
  2. 1 2 "Has styrofoam become a generic trademark?". 31 January 2020. Retrieved April 29, 2021.
  3. Boundy, Ray H.; Amos, J. Lawrence (1991). A History of the Dow Chemical Physics Lab. New York: Marcel Dekker, Inc. pp. 117–128. ISBN   0-8247-8097-3.
  4. US 2450436,Otis Ray McIntire,"Manufacture of cellular thermoplastic products",published 1948-10-05,issued 1948-10-05
  5. "What is the Difference between EPS Polystyrene and (styrofoam)?".
  6. Dow Announces New Technology for STYROFOAM Insulation
  7. "Geotechnical applications of Styrofoam". Dow Chemical. Retrieved 2009-10-28.
  8. "Engineering considerations when building on permafrost" . Retrieved 2007-08-30.
  9. "STYROFOAM Brand Foam Crafts" . Retrieved 2010-12-31.
  10. "(Styrene) Fact Sheet: Support Document (CAS No. 100-42-5)" (PDF). EPA . December 1994. Archived from the original (PDF) on 24 September 2015. Retrieved 8 January 2020.
  11. "STYRENE (Group 2B)". INCHEM . 2002. Retrieved 8 January 2020.