This article gives the history and properties of Celotex® Thermax and other foam board insulating products. Celotex® foam board insulation was later purchased by Dow Chemical who continues to market polyisocyanurate foam insulating board. Page top photo: Celotex® Tuff-R polyisocyanurate foam board insulation.
This article series assists building buyers, owners or inspectors who need to identify foam board insulation and to address possible presence of asbestos in buildings.
Polyisocyanurate insulation products have an R-value of about R 7.04 to R 7.20 per inch. Shown in the photo, Celotex Thermax solid foam insulating board with aluminum foil facing. With a stabilized 3/4" air space on one side of this insulating board its R-value at 1" increases to R10.
1/2" Celotex Thermax was rated at R 3.8, increasing to R 6.4 with the air space we specified above.
4" Celotex Thermax was rated at R 28.8, increasing to R 31.6 with the air space we specified above.
According to product markings we show below, modern Celotex or more recently Dow polyisocyanurate insulation complies with requirements of ICBO, BOCA, SBCCI, CABO, ICC, HUD/FHA, Federal Specification HH-I-1972/1, Class 2, ASTM C 1289, Type 1, Class 2. The product is described in ICBO Report #3223, SBCCI #9574A, and BOCA #89-45.
In Canada see CCMC Evaluation Report #08433-L. The product shown below also is stamped with logos of NAHB, ETL, Good Housekeeping, and Energy Star.
Reply: some Celotex Thermax™ laminate insulating board products contained asbestos at least in patent disclosures
Celotex Thermax™ as illustrated by your first photo above was (and is currently as a Dow Thermax™ product) a foil-faced insulating board comprised chiefly of foam insulation, laminated with aluminum foil or possibly kraft paper.
Asbestos appeared in some, probably not all, foam insulating boards made up to the early to mid 1980's, particularly or more likely in fire-resistant products that incorporated a layer of asbestos paper.
The second photo you provided later [above] has been cut-open.
Enlarging the photo (enlarged view above) I don't see any sign of an asbestos paper, though of course a closer look in the field would be in order.
[Click to enlarge any image]
Above and then below we show your images of the labeling and text on this Celotex Thermax insulating board. Readers will want to click to enlarge each image to read the details of the Celotex insulation specifications.
This insulation meets several standards and specifications including Energy Star ratings - a rating that well post-dates asbestos-based insulation for in-home use. The company's stamping describes this product as a "Glass fiber reinforced polyisocyanurate foam board with reflective aluminum foil facers."
Patents Establishing Use of Asbestos in Some isocyanurate foam products
Foil faced and structural laminate type insulating boards using foam and aluminum or other facings have patents that help identify the product contents.
Hipchen, Donald E., Michael J. Skowronski, and Joseph R. Hagan. "Structural laminate and method for making same." U.S. Patent 4,118,533, issued October 3, 1978.
A structural laminate comprises at least one planar facing sheet with a rigid foam attached to one surface of the facing sheet. The rigid foam is characterized in that the major recurring chemical linkage therein is the isocyanurate moiety.
Distributed substantially evenly throughout the foam is a mat of long straight glass fibers arranged in layers substantially parallel to the facing sheet.
The process for producing this structural laminate comprises the steps of contacting a thin, substantially incompressible yet expansible mat of long straight glass fibers with a foam-forming mixture of an organic polyisocyanate and a diol, positioning a facing sheet on each face of the mat, and passing the facing sheets having the mat and the foam-forming mixture there between through the nip of two rotating rolls.
Watch out: you are absolutely right to ask if asbestos ever was used in insulating foam boards. Indeed the patent I cite above as well as at least one other patent describe possible use of asbestos in these insulating board products.
Excerpt from Hipchen: The structural laminate of the present invention has at least one but preferably has two facing sheets, one on either side of the foam core. These facing sheets can be constructed of a wide variety of non-flammable materials such as asbestos, glass fibers, or metals.
In the broadest aspects of the invention, any metal can be employed such as copper, brass, iron, steel, or aluminum. Aluminum is the preferred metal because of its ductility and ease with which it can be manufactured into a material of suitable thickness.
Celotex is the original assignee of this patent. That does NOT tell us what Celotex products actually contain when marketed.
Here is a later patent citing asbestos in foam insulating boards:
Ohashi, Takashi, Toru Okuyama, Akira Suzuki, and Katsuhiko Arai. "Asbestos-metal surfaced urethane modified polyisocyanurate foam." U.S. Patent 4,292,361, issued September 29, 1981.
A fireproof laminate passing Grade 2 incombustibility according to Japanese Industrial Standard (JIS) A-1321 combustion test is disclosed.
The laminate comprises a urethane modified polyisocyanurate foam as a core material and particular surface materials piled on both sides of the foam through self-adhesion of the foam and has a density of the core material of 0.02-0.04 g/cm3 and a total thickness of not more than 30 mm.
Notice that where fireproof or fire resistant products were being marketed asbestos was more likely to appear.
Excerpt from Ohashi:
This invention relates to novel fireproof laminates using a urethane modified polyisocyanurate foam as a core material.
More particularly, it relates to fireproof laminates having excellent fireproof property and low-smoke development, which are obtained by using the above core material having a defined density and an asbestos paper lined with a metal foil as a surface material for at least one side of the core material and piling them one upon another at a total thickness of a defined range through self-adhesion of the urethane modified polyisocyanurate foam.
In the U.S. in the 1980's Celotex Thermax insulating board was described by the Celotex Company (Jim Walters corporation, Tampa) as an insulating sheathing board with an R-value of 5.4 for a 3/4" thick board: higher R than its competitors at the time as it was compared with foam insulating board sold by Dow, WR Grade and Simplex. (Popular Mechanics, October 1984, advertisement p. 139)
In July 2001 Celotex's rigid foam insulation business was purchased by Dow Chemical which explains why most web searches for Celotex Thermax insulating board will turn up Dow Chemical company listings for Thermax products.
I have not found reports of use of asbestos in foam currently-marketed (2016) insulating foam board products. But laminated foam insulating board products sold in North America up to about the mid 1980's might indeed contain asbestos, particularly in special fire-resistant applications.
At FOAM BOARD INSULATION TYPES you can see more photos of Celotex-branded foam insulating board, principally a polyisocyanurate foam product.
Constituents & Properties of Modern Insulating Foam Board from Dow Chemical
Modern foam insulating board products may use fiberglass or other reinforcing fibers however. Shown above: Dow Super Tuff R foil faced insulating foam board at a Home Depot store in Poughkeepsie, NY. This product is rated by the Dow Chemical company as R 3.3 in 1/2" board and R 6.5 in 1" thickness board.
Shown in our second photo above in which some shopper (not me) peeled back part of the foam board facing, you may see that some insulating board products use aluminum foil only on one side, facing the other side with paper or plastic.
The Dow Chemical company notes that the installer can obtain an additional R 2.8 if the insulation is installed with an air space on the reflective side - the side without printing.
Contemporary Thermax branded insulating board or sheathing board, a Dow Chemicals product, is described by DOW as follows:
THERMAX™ Heavy Duty Insulation consists of a glass-fiber-reinforced polyisocyanurate
foam core faced with nominal 4 mil embossed white thermoset-coated aluminum on one side and 1.25 mil
embossed aluminum on the other. It can be installed exposed to the interior without a thermal barrier.
Dow Chemical currently markets several versions of Thermax™ to meet different needs such as building insulating sheathing, heavier duty insulating sheathing or insulating board for metal buildings, etc. Here is a copy of one of the current Thermax™ Sheathing products now produced and sold by the Dow Chemical Company and an example Dow Chemical MSDS for a typical Thermax insulating sheathing product.
Dow Thermax™ Sheathing[PDF] product literature, retrieved 2016/11/13, original source: http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_0940/0901b80380940471.pdf?filepath=styrofoam/pdfs/noreg/179-04015.pdf&fromPage=GetDoc
Excerpt: THERMAX™ Sheathing is a non-structural,
rigid board insulation consisting of a
foam core laminated between 1.0 mil
smooth, reflective aluminum facers on
both sides. The glass-fiber reinforcement
contributes to improved fire performance
and dimensional stability. THERMAX™
Sheathing can be installed exposed to the
interior without a thermal barrier.
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Do some Celotex® ceiling tiles contain asbestos?
We bought a house that was built in the 50's - it has what I THINK is a Celotex ceiling (or some copy of Celotex) - it's in horrible shape and needs to be taken down - what are your thoughts on it containing asbestos, considering the age? - Saundra
Reply: Yes. In the article above we provide a list of Celotex® fiber-board, ceiling covering, acoustical, sound control & other products that may contain asbestos
Keep in mind that Celotex and other insulating board panel and ceiling tile and panel manufacturers produced a range of products, many of which may contain asbestos, but others made of organic fibers, wood fibers, cane fibers may not contain asbestos. The Celotex ceiling products division was sold to Certainteed Saint-Gobain beginning in 1999. Certainteed continues to produce and sell both fiberglass and mineral-fiber ceiling products, as well as gypsum based ceiling materials. You may find look-alike products by searching that company's product catalogs.
Modern ceiling products do not contain asbestos. Using Certainteed as an example, [www.certainteed.com] you can obtain an MSDS (Material Data Safety Sheet) for each of the company's products. Common modern ceiling product ingredients include fibrous glass wool, urea formaldehyde resin, and fiberboard products contain slag wool, starch, cellulose [wood fibers], perlite, crystalline silica, and clay. It's worth noting that even modern building products can present health hazards if they are not handled properly. For example crystalline silica can cause nose, throat, and lung irritation. 
If you are not sure of the product brand and age of the ceiling covering, and are not sure whether or not the product contains asbestos, and if we accept as a "given" that your ceiling covering needs to be removed, there are two reasonable ways to proceed:
Dampen and remove a small sample of the material (about 1 sq.in.) and send it to a certified asbestos testing lab for identification. Typically the test is inexpensive (less than $100), and the result can close any argument about how to proceed with handling the material.
Assume based on age (for example an acoustical ceiling installed before 1973) that the material may contain asbestos and handle its removal accordingly. To be safe, I'd assume that an acoustical ceiling product made before 1981 contains asbestos, and I'd keep in mind that a ceiling installed even in the few years after 1981 could have made use of old stock made before that date.
For most projects and certainly any area as large as a basement ceiling, we recommend hiring a professional company who knows proper demolition and cleaning procedures. An amateur job of asbestos removal, even if it is legally permitted in your area, risks not only health hazards to the workers, but also the creation of a still more costly cleanup job if proper dust and debris control procedures are not followed.
To elaborate your question about asbestos-containing products made by Celotex, the company produced a wide range of fiber-based insulation products such as insulating boards and panels and the company continues to produce modern (non-asbestos-containing) versions of those products today.
At FIBERBOARD SHEATHING, Celotex Homasote & Other we include identifying photographs of some Celotex products.
Question: is it safe to clean Celotex board ceilings in our 1935 church?
Is it safe to clean the ceiling of our Church which has celotex boards and believed to have been installed in 1935? - Len Taylor 10/25/12
"Safe" depends - the greatest hazard of cleaning a church ceiling is falling off of a ladder. I don't know what kind of cleaning you are talking about, nor what the concern was; But if you avoid aggressive cleaning that damages the material and creates fibers and dust, you should be ok. Celotex fiberboard insulating panels are not an asbestos product - as you can read at SHEATHING, FIBERBOARD
Question: Asbestos in paper HVAC duct wrap
(May 24, 2015) Anonymous said:
What kind of asbestos was used in paper duct wrap in 1908? Was it chrysotile or another form?
Question: asbestos in Louisiana-Made Ceiling Tiles from 1971?
(Aug 5, 2015) Melanie said:
I need to find out if our ceiling tile contains asbestos. They were manufactured in Marrero, LA in 1971. Numbers found on the box are: 32286 and 270. Can you help? Thank you.
Check with Louisiana Acoustical & Drywall Materials is a subsidiary of GMS, 2601 Samford Ave
Shreveport, LA 71103
Question: need to know if Celotex mineral wool contains asbestos
(Nov 9, 2015) homeowner said:
I need to know if Celotex mineral wool contains asbestos. This is loose fiber insulation in walls and attic found in home that was renovated with this product in 1959. There is a package that says "Celotex Mineral Wool,fire retardant" in the home.
Mineral wool is not an asbestos product. Only if yours was cross-contaminated might we expect to find asbestos in it.
See inspectapedia.com/insulation/Rock_Wool_Insulation.php for details.
(Jan 30, 2016) jane said:
We are rehabbing a house that has Celotex tile board as the ceiling in the upstairs. I'm guessing it was put up in the early 1940's. I have a box with a label and wondered if you could tell me if they contain asbestos. Type No.91 Joint Es Size 1/2x16"x16" sq. Ft.88.89 No.Pieces 50
Jane, please use the page bottom CONTACT link to send some pictures of the box labeling on all sides and the tile bith sides and we can comment further as well as researching further.
Question: Realtor says ceiling panels are made of sugar cane not asbestos
(May 28, 2016) tclark said:
I'm looking at purchasing a home built in 1929. All of the walls and ceilings are finished with panels that our realtor is calling Celotex panels. She states that they are a by product of sugar cane which would not be surprising as the town in which it is located produces sugar cane. I see on this site that this product does not contain asbestos. How can I be sure that this is actually the product that was used vs one of the others that do contain asbestos? Also, how is this material repaired when needed? I can post photos if it will help
Your realtor may or may not be correct as cellulose-based (wood-based) insulating board panels were made from a variety of products, not just sugar cane.
But as you may read in the article above, she is right that some Celotex was made of that material. Or perhaps she was sugar coating the sale for you. Did you ask the realtor how she knew for sure what the material was, who made it and what were its constituents and how she knew that it was made at a plant that was not at risk of asbestos cross-contamination.
To know for certain if a product contains no asbestos, with no more data than your question, you'd have to have a sample tested by a certified asbestos test lab (about $50.) though it may not be justified in this case.
You can use our page top or page bottom CONTACT link to send me photos. The Comment Box software does not yet let readers post photos, though many of us have asked for that feature.
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Celotex ceiling products division was purchased by Ceiling Products & Gypsum Wallboard (BPB) of the U.K. beginning in 1999
Celotex roofing products division was purchased by Certainteed Corporation (Valley Forge PA) beginning in 1999
 Certainteed Ceilings, Adagio fiberglass/mineral fiber composite acoustical ceiling product MSDS, web search 11/22/2011, original source: certainteed.com/resources/Adagio_MSDS_2010.pdf
 "Board of Education for the School District of the City of Detroit v. Celotex, et al., Circuit Court of Wayne County, Michigan, No. 84-429634-ND"
 Armstrong Corporation, web search 6/22/12, original source: http://www.armstrong.rs/commclgeu/eu1/uk/rs/FAQ_other.html, [Copy on file as Armstrong_Ceil_Asbestos.pdf]
 Lipsitz & Ponterio, LLC, "Carpenters and Mesothelioma", Lipsitz & Ponterio, LLC, 135 Delaware Ave, 5th Floor, Buffalo, NY 14202-2415 (716) 849-0701. Web search 6/22/12, original source: http://www.mesotheliomacarpenter.com/carpenters-asbestos-exposure/ceiling-tile/ [Copy on file as LiIpsitz_Asbestos.pdf]
 INACHI forum discussion about asbestos ceiling tiles, web search 6/22/12, original source: http://www.nachi.org/forum/f18/asbestos-ceiling-tiles-14709/ [Copy on file as Inach_Ceil_Asbestos.pdf]
 Celotex [UK] History, Celotex Insulation Specialists, web search 6/30/12, original source: http://www.celotex.co.uk/celotex-history [Copy on file as Celotex_History_UK.pdf ]
 Wikipedia provided background information about some topics discussed at this website provided this citation is also found in the same article along with a " retrieved on" date. NOTE: because Wikipedia entries are fluid and can be amended in real time, we cite the retrieval date of Wikipedia citations and we do not assert that the information found there is necessarily authoritative. Web search 6/30/12: "Ceiling Tiles"
 Brian Greer, "History of Tin Ceilings", Brian Greer's Tin Ceilings, web search 6/30/12, original source: http://www.tinceiling.com/company/historytin.php
 Armstrong Corporation, "Corporate History: a Historical Summary", web search 6/30/12, original source: http://www.armstrong.com/corporate/corporate-history.html
 "Ceilings Pressed in Time", Old House Journal, web search 6/30/12, original source: http://www.oldhousejournal.com/ceillings_pressed_in_time/magazine/1070
 Steven Mlynarek, Morton Corn, Charles Blake, "Asbestos Exposure of Building Maintenance Personnel", Regulatory Toxicology and Pharmacology, 23, 213–224 (1996) ARTICLE NO. 0045, http://library.certh.gr/libfiles/PDF/GEN-PAPYR-4810-ASBESTOS-by-MLYNAREK
 National Institute of Occupational Safety and Health (NIOSH) (1989). In NIOSH Manual of Analytical Methods (P. M. Eller, Ed.),
Method 7400. NIOSH, Washington, DC.
 U.S. Environmental Protection Agency (USEPA—Green Book) (1990). In Managing Asbestos in Place: A Building Owners Guide to Operations and Maintenance Programs for Asbestos-Containing
 U.S. Department of Labor, Occupational Safety and Health Administration (USDOL) (1994). In Occupational Exposure to Asbestos:
Final Rule, FR Vol. 59, No. 153:40964–41162. Materials, Report 2OT-2003. USEPA, Washington, DC.
 U.S. Department of Labor, Occupational Safety and Health Administration
(USDOL) (1986). In Occupational Exposure to Asbestos: Tremolite,
Anthophyllite, and Actinolite: Final Rule, FR Vol. 51,
 U.S. Environmental Protection Agency (USEPA) (1990). In Environmental Asbestos Assessment Manual, Superfund Method for the Determination of Asbestos in Ambient Air, Part 2, Technical Background Document, Report EPA/540/2-90/005 b. USEPA, Washington, DC
 Ceiling - Frequently Asked Questions, Armstrong Corporation, web search 6/30/12, original source: http://www.armstrong.com/resclgam/na/ceilings/en/us/article17697.html
 BPB America Inc.,
5301 West Cypress St., Suite 300,
Tampa, FL 33607,
Web: www.bpb-na.com. Acoustic ceiling tile & accessories.
 Affa Tile Company
No. 1116/8, Poonamalee High Road, Opposite Hotel Shan Royal, Koyambedu
Chennai, Tamil Nadu - 600 107, India, E-Mail: firstname.lastname@example.org website: http://www.affatiles.com Tel:044-24757498, 044 - 24757497
 Made-in-China.com, online sevice to connect buyers with product suppliers in China, web search 6/30/12
 "Directive 2003/18/EC of the European Parliament and of the Council of 27 March 2003 amending Council Directive 83/477/EEC on the protection of workers from the risks related to exposure to asbestos at work". Publications Office of the European Union. 27 March 2003 Web search 6/30/12, original source: http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=CELEX:32003L0018:EN:NOT,
 H. M. Murray, testimony before the Departmental Committee on Compensation for Industrial Diseases "Minutes of Evidence, Appendices and Index", 1907. p. 127
 D. Auribault, "Note sur l'Hygiène et la Sécurité des Ouvriers dans les Filatures et Tissages d'Amianté (On hygiene and security of the workers in the spinning and weaving of asbestos)" in Le Bulletin de l'Inspection du Travail, 1906, pp 120–132.
 Wikipedia entry on Asbestos and various citations from that article, web search 6/30/12, original source: en.wikipedia.org "Asbestos"
Asbestos Identification and Testing References
Asbestos Identification, Walter C.McCrone, McCrone Research Institute, Chicago, IL.1987 ISBN 0-904962-11-3. Dr. McCrone literally "wrote the book" on asbestos identification procedures which formed
the basis for current work by asbestos identification laboratories.
Stanton, .F., et al., National Bureau of Standards Special Publication 506: 143-151
Pott, F., Staub-Reinhalf Luft 38, 486-490 (1978) cited by McCrone
Asbestos NESHAP ADEQUATELY WET ASBESTOS GUIDANCE, EPA340/1-90-019, December 1990, U.S. ENVIRONMENTAL PROTECTION AGENCY, Office of Air Quality Planning and Standards, Stationary Source Compliance Division, Washington, DC 20460,original web source: http://www.epa.gov/region04/air/asbestos/awet.htm
Asbestos products and their history and use in various building materials such as asphalt and vinyl flooring includes discussion which draws on ASBESTOS, ITS INDUSTRIAL APPLICATIONS, ROSATO 1959, D.V. Rosato, engineering consultant, Newton, MA, Reinhold Publishing, 1959 Library of Congress Catalog Card No.: 59-12535 (out of print, text and images available at InspectAPedia.com).
"Handling Asbestos-Containing roofing material - an update", Carl Good, NRCA Associate Executive Director, Professional Roofing, February 1992, p. 38-43
EPA Guidance for Controlling Asbestos-Containing Materials in buildings, NIAST, National Institute on Abatement Sciences & Technology, [republishing EPA public documents] 1985 ed., Exposure Evaluation Division, Office of Toxic Substances, Office of Pesticides and Toxic Substances, U.S. Environmental Protection Agency, Washington,D.C. 20460
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