Here is some general guidance to use when choosing flooring materials:
The Flooring Products Hazard Spectrum encompasses a wide variety of flooring options, including resilient, ceramic tile, wood, and carpet. The spectrum excludes adhesives which may be required to install the products. Refer to the Flooring Installation Hazard Spectrum for guidance on adhesives and other installation methods.
Hazardous chemicals are common in various flooring products and can be released from products, exposing installers and residents. Of particular concern is the impact on children who are more vulnerable due to their size and developing bodies.
The production of flooring materials can also have significant impacts on nearby communities and the broader environment through the release of hazardous chemicals. These impacts can occur at the facilities that make the flooring products as well as those farther back in the supply chain. For example, many flooring materials are made using plastic or other petroleum-derived materials. Oil and gas extraction and processing have significant impacts on surrounding communities.
Many flooring materials are manufactured with a protective topcoat, a standard practice in the industry. These topcoats are typically polyurethane or epoxy-based resin hardened with aluminum oxide and exposure to ultraviolet light. The primary health concern stemming from these coatings is for workers who could be exposed to the coating while it is wet in the factory. However, some products include nanomaterials in topcoats, and these may be a concern for residents as well. The National Institute for Standards and Technology (NIST) has raised concern that “substantial” amounts of nanomaterials in topcoats may be released via repeated mechanical forces such as walking on, mopping, and polishing floors. The federal agency is concerned that, “such release of the nanosize material is potentially harmful to the occupants, particularly children who typically experience greater exposure to substances deposited at floor level.” More research is needed on the health and environmental impacts of nanoparticles and how often they are being used in flooring products. Nanomaterials that may be used in topcoats include nano-sized aluminum oxide, silica, or silver nanoparticles. More on silver nanoparticles below.
Given the widespread presence of topcoats in resilient and wood flooring, topcoats are a high priority for green chemistry solutions.
Encourage manufacturers to fully disclose the content (including topcoats, stain-repellent treatments, and antimicrobials) and associated health hazards for flooring products through the industry’s collaborative, user-designed open standard, Health Product Declaration (HPD). In addition, there may be new, innovative flooring options that are not yet included in our hazard spectrum. Request HPDs for these products so their content can be assessed and compared to standard materials. More background and resources for requesting transparency are available on HomeFree’s Why Transparency Matters page.
Here is some general guidance to use when choosing flooring materials:
Linoleum is a very good option for flooring to avoid toxic substances. Excluding the topcoat, it’s typically made from bio-based and low hazard ingredients - see the Read More section above for more information on topcoats.
Be aware that some linoleum flooring has optional layers for acoustic insulation or floating floor installation which can add additional hazards. Floating floors do, however, avoid the use of a potentially hazardous adhesive, so they are still a preferred flooring option. See the Flooring Installation Hazard Spectrum for more information.
Pre-finished solid wood floors are a very good flooring option. Made from a single piece of wood, and purchased with a stain and topcoat already applied, this type of flooring is preferred over site-finished products because the chemically intensive finishing processes takes place in a more controlled environment.
If possible, find flooring that can be installed without an adhesive.
Using concrete that is already in place as the flooring material can be a great way to reduce human and environmental health impacts by using less material in a space. However, it is important to keep in mind that different types of concrete finishes can add chemicals of concern. For example, accessory products used with polished concrete flooring can contain per- and polyfluoroalkyl substances (PFAS), often referred to as "forever chemicals" because they can persist in the environment for long periods of time. Many have also been found to be toxic and to bioaccumulate.
Densifier formulations are generally simple with few hazards, but some products may contain PFAS. Always check with the manufacturer to verify that PFAS are not present.
Ceramic tiles made without toxic glazes can be relatively low-impact materials for a flooring (or wall) installation. Tiles made in the USA are typically free of lead compounds in their glazes. Look for tile product literature that identifies where they’ve been made, and what they are made of, including frits, glazes, and pigments. Unglazed tiles are most preferred.
Avoid tiles with non-specific post-consumer recycled content. These contents may be old cathode ray tubes (CRTs) from TV sets and computer monitors. They contain high concentrations of lead. Tiles with CRT content are sometimes called CRT tiles.
Accessories used with ceramic tiles can also introduce chemicals of concern. Avoid using epoxy grouts and avoid sealers that contain “forever chemicals” (per- and polyfluorinated alkyl substances (PFAS)) — these sealers are typically advertised as “oil-repelling.”
For more information, read Made in the USA: A Healthy Choice for Ceramic Tiles
Solid wood floors are a good flooring option, made from a single piece of wood without additional binder. When the boards are installed unfinished and require stains and topcoats to be applied within the building, those volatile and sometimes flammable chemicals can be brought into the project in an uncontrolled way, exposing installers and others nearby.
Prefer pre-finished solid wood floors if possible, and look for flooring that can be installed without an adhesive.
Homogeneous cork floors are a relatively low hazard flooring option made up of natural cork granules, a binder, and a finish. The binders are commonly based on isocyanates, which are asthmagens. This is primarily a concern during manufacturing.
Cork floating floors can have additional hazards. Floating floors do, however, avoid the use of a potentially hazardous adhesive, so are still a preferred flooring option. See the Flooring Installation Hazard Spectrum for more information.
Prefer products that are pre-finished in the factory and don’t require additional on-site finishing. Be aware that some cork flooring products can include a layer of PVC (vinyl) or a decorative layer that includes PVC or a similar material. Avoid these products (see the sections on vinyl flooring below).
Cork veneer products can contain additional components and are not included in the Hazard Spectrum.
Many PVC-free resilient flooring options are available. They may also be called non-vinyl polymeric composite flooring. This category covers PVC-free resilient flooring that isn’t linoleum, rubber, polyurethane, or cork flooring. These products can vary in the type of binder used including polyethylene, polypropylene, ethylene vinyl acetate, polyester, and acrylics or some combination of these. Different binders pose different concerns in terms of potentially hazardous residual catalysts or monomers in the finished product and in terms of life cycle impacts. However, these binders are typically preferable to polyurethane and polyvinyl chloride.
PVC-free resilient flooring can be homogeneous (the same composition throughout) or heterogeneous (with layers of different composition within the flooring). Homogeneous PVC-free resilient floors are commonly made of a binder, filler, colorants, and additional additives as well as a protective finish. Heterogeneous floors have multiple layers and may include a printed layer which may contain dyes and paper or a polymer film. Others may have additional layers such as a fiberglass layer within the floor and/or a backing material. Additional layers may add additional hazards.
Some products contain pre-consumer recycled content, likely from the limestone filler, which is sometimes designated as recycled content. Some may contain biobased content, typically at a low percentage of the overall product, less than 2%.
Most of these products do not require additional waxing or polishing but some do; check specific product information. Accessory materials can add additional hazards.
Formaldehyde-based binders emit formaldehyde (a carcinogen and asthmagen) over time. Preferring floors made with an NAUF (no added urea formaldehyde) binder at a minimum is a good practice; an NAF (no added formaldehyde) binder is even better. See our Composite Woods Hazard Spectrum for a further ranking of composite wood binders.
When possible, prefer a product that does not require an adhesive for installation.
Floors made from new rubber do not contain the highly toxic legacy contaminants often found in recycled rubber floors (see below) and are generally low hazard during use. Some rubber floors contain cork and are advertised as “rubber cork” floors. Typically, cork only represents a small percentage of the product (<8%), and these floors can be made with or without crumb rubber. For both rubber and rubber cork floors, there are life cycle concerns because of the hazardous inputs used in rubber production, but virgin rubber floors are still preferable to vinyl from a material health perspective.
Look for products that clearly indicate they are made from virgin rubber, or check with the manufacturer to verify that they do not contain tire-derived crumb rubber or other hazardous recycled content.
Laminate floors are a type of engineered floor made by layering a sheet of decorative paper infused with a binder over a plank of composite wood. The pattern on the paper is usually intended to resemble the grain of a wood floor. Like other engineered floors, care should be taken to find products with a NAUF (no added urea formaldehyde) or NAF (no added formaldehyde) binder, and that do not require adhesives for installation. Note that unlike solid wood floors or other engineered floors, laminates cannot be sanded or refinished. It is also worth noting that laminate flooring manufacturing has had supply chain quality control issues leading to some imported products with formaldehyde emissions well above regulatory limits. Prefer products made in the US.
Carpeting is variable and can be made in many combinations of backings, face fibers, and surface treatments. Carpet with this ranking on the hazard spectrum does not contain the chemicals and chemical classes that are the highest priority to avoid: fly ash, vinyl and polyurethane backings, and PFAS.
Vinyl and polyurethane backings have significant life cycle concerns and can contain hazardous additives. Alternative backings like polyolefin are less hazardous and more readily recyclable at the end of the product’s life.
Fly ash is commonly used as a filler in carpet tile backing, and it contains heavy metal contaminants. Alternative fillers include calcium carbonate and ground, recycled post-consumer container glass which are becoming more common and don’t contain toxic substances.
Per- and polyfluoroalkyl substances (PFAS), commonly used in stain-repellent treatments for carpet fibers, are a high priority to avoid. Alternative treatments are available and appear to be better from a health standpoint, but greater transparency about their chemical identities and hazards is still needed.
Additional chemicals of concern that may be found in carpet include antimicrobials and flame retardants. Carpet is also the flooring product type with the shortest service life, meaning it will need to be replaced more frequently, compounding the life cycle impacts.
Quick tips for vetting carpet products:
For more information on carpet content and carpet recycling, see the brief on HomeFree or the full report here: Eliminating Toxics in Carpet: Lessons for the Future of Recycling.
Polyurethane resilient flooring is similar to PVC-free resilient flooring in terms of composition but is based on isocyanate chemistry and has greater life cycle concerns than many other polymers. Isocyanates are asthmagens and are primarily a concern during manufacturing of PU flooring. Polyurethane resilient flooring commonly has bio-based inputs (vegetable oils) accounting for around 29% of the product. These floors are ranked orange on the hazard spectrum because there are more hazardous chemicals associated with their life cycle than other PVC-free resilient flooring, but they are still preferred over vinyl.
Engineered floors are made by pressing layers of wood together with a binder into a solid board. When the boards are installed unfinished and require stains and topcoats to be applied within the building, volatile and sometimes flammable chemicals can be brought into the project in an uncontrolled way, exposing installers and others nearby.
Preferring floors made with an NAUF binder (good), or NAF binder (better) can decrease exposure to formaldehyde (a carcinogen and asthmagen) after the installation is complete. Note that some floors are typically sold unfinished, but can be pre-finished by the manufacturer if requested.
Because of the toxic processes required to make polyvinyl chloride (PVC), commonly known as vinyl, and the toxic pollution created when it is disposed of, vinyl floors of any kind are not a preferable material. However, in the instance where vinyl is used, vinyl that has been reformulated to be free of hazardous phthalate plasticizers and doesn’t contain toxic or unnamed recycled content should be preferred. Stain repellent treatments are most often associated with carpet, but some vinyl floors may be treated with them as well. Avoid these whenever using vinyl flooring to avoid PFAS chemicals.
For more information on PVC see this joint publication between HBN and Perkins + Will.
While US manufacturers have phased out toxic lead compounds from ceramic tile glazes, overseas manufacturers may continue to use them. About seventy percent of tiles sold in the US are imported, mainly from China, Mexico, Italy, Spain, and Brazil. Unless manufacturers specifically state otherwise, the safest approach is to assume that glazed tiles not made in the USA contain lead (a PBT with cancer, developmental, and reproductive hazards). In addition, tiles with post-consumer recycled content from cathode ray tubes (CRTs), sometimes called CRT tiles, also contain lead from this recycled material.
When the location of manufacture cannot be determined, the safest tile choices are unglazed tiles, or glazed tiles that are rated high for traffic abrasion (an abrasion resistance rating of IV or V according to ASTM C1027/ANSI A137.1, sometimes referred to as a PEI rating). The glazes of these tiles are less likely to wear down over time and introduce any lead that might be present into the living space.
For more information, read Made in the USA: A Healthy Choice for Ceramic Tiles
Many finishes for concrete flooring contain chemicals of concern. For example, accessory products used with polished concrete flooring often contain per- and polyfluoroalkyl substances (PFAS). These chemicals are referred to as "forever chemicals" because they can persist in the environment for long periods of time, and many have also been found to be toxic and to bioaccumulate.
Penetrating concrete sealers are also not a preferred option because they use chemicals that are based on cyclosiloxanes. These PBT chemicals can be introduced into the environment and are also found as residuals in these products.
Rubber sheet or tile flooring made with crumb rubber is not a healthy option. Crumb rubber (also referred to as post-consumer recycled content in this type of product) is sourced from recycled tire scrap and can include significant additional hazards. Much research has been done considering the presence of hazardous chemicals in crumb rubber. These chemicals include phthalates, heavy metals, processing oils, polycyclic aromatic hydrocarbons (PAHs), and other additives. Many of these chemicals are carcinogens, mutagens, and/or reproductive and developmental toxicants. In addition, high rates of offgassing of volatile chemicals have been measured from floors containing recycled tires.
Avoid using rubber or rubber cork floors made with crumb rubber. Never use products designated for exterior or interior-exterior applications inside a building.
For more information read this 2013 report by Healthy Building Network.
Carpeting is variable and can be made in many combinations of backings, face fibers, and surface treatments. Materials of concern in carpets include:
Coal fly ash used as filler in some carpet backings. Fly ash is a waste product from the combustion of coal and can be contaminated with mercury (a PBT developmental and reproductive toxicant) and other metals present in the coal itself.
Per- and polyfluoroalkyl substances (PFAS) used as stain-repellent treatments. Health hazard information is not available for all the chemicals within this large group, but PFAS as a class have been identified as chemicals of concern because many have been found to be highly toxic, persist in the environment, and build up in body tissues.
Vinyl and polyurethane backings. Because of significant life cycle concerns, vinyl and polyurethane are not preferred materials. Polyurethane is based on isocyanate chemistry. Isocyanates are a leading cause of workplace asthma, so they present a concern during manufacturing, and residuals may be present in the final product. Vinyl and polyurethane backings commonly contain hazardous organotin catalysts, and vinyl backings may be plasticized with hazardous phthalates.
Carpets containing all these substances of concern are rated as red on the hazard spectrum - those that avoid them all are rated orange, see above.
For more information on carpet content and carpet recycling, see the brief on HomeFree or the full report here, Eliminating Toxics in Carpet: Lessons for the Future of Recycling.
Because of the toxic materials required to make vinyl and the toxic pollution created when it is disposed of, vinyl floors of any kind are not a preferable material.
Vinyl floors, whether sheet, tile, or plank, made in the conventional way, are a poor choice for a flooring material. Hazardous phthalate plasticizers, and stabilizers based on organotins which can be reproductive toxicants, present hazards to occupants when they leach out of the floors and into the living space.
In addition, the inclusion of recycled vinyl in new products is a major pathway for the introduction of hazardous materials. Because vinyl products of all kinds may be recycled together, hazardous lead, arsenic, PCBs, and plasticizers can be found in post-consumer recycled vinyl.
For more information on vinyl, see this joint publication between HBN and Perkins + Will. For more information on the hazards of post-consumer recycled vinyl, see this report by Healthy Building Network.
Unless otherwise noted, product content and health hazard information is based on research done by Healthy Building Network for Common Product profiles, reports, and blogs. Links to the appropriate resources are provided.
 Bi, Chenyang, Juan P. Maestre, LiG Hongwan, GeR Zhang, Raheleh Givehchi, Alireza Mahdavi, Kerry A. Kinney, Jeffery Siegel, Sharon D. Horner, and Ying Xu. “Phthalates and Organophosphates in Settled Dust and HVAC Filter Dust of U.S. Low-Income Homes: Association with Season, Building Characteristics, and Childhood Asthma.” Environment International 121 (December 2018): 916–30. https://doi.org/10.1016/j.envint.2018.09.013.; Mitro, Susanna D., Robin E. Dodson, Veena Singla, Gary Adamkiewicz, Angelo F. Elmi, Monica K. Tilly, and Ami R. Zota. “Consumer Product Chemicals in Indoor Dust: A Quantitative Meta-Analysis of U.S. Studies.” Environmental Science & Technology 50, no. 19 (October 4, 2016): 10661–72. https://doi.org/10.1021/acs.est.6b02023.
 Mark D. Miller et al., “Differences between Children and Adults: Implications for Risk Assessment at California EPA,” International Journal of Toxicology 21, no. 5 (October 2002): 403–18, https://doi.org/10.1080/10915810290096630.; Bi, Chenyang, Juan P. Maestre, LiG Hongwan, GeR Zhang, Raheleh Givehchi, Alireza Mahdavi, Kerry A. Kinney, Jeffery Siegel, Sharon D. Horner, and Ying Xu. “Phthalates and Organophosphates in Settled Dust and HVAC Filter Dust of U.S. Low-Income Homes: Association with Season, Building Characteristics, and Childhood Asthma.” Environment International 121 (December 2018): 916–30. https://doi.org/10.1016/j.envint.2018.09.013.; Mitro, Susanna D., Robin E. Dodson, Veena Singla, Gary Adamkiewicz, Angelo F. Elmi, Monica K. Tilly, and Ami R. Zota. “Consumer Product Chemicals in Indoor Dust: A Quantitative Meta-Analysis of U.S. Studies.” Environmental Science & Technology 50, no. 19 (October 4, 2016): 10661–72. https://doi.org/10.1021/acs.est.6b02023.
 “Environmental Impacts of Natural Gas,” Union of Concerned Scientists, June 19, 2014, https://www.ucsusa.org/resources/environmental-impacts-natural-gas; Tim Donaghy and Charlie Jiang, “Fossil Fuel Racism: How Phasing Out Oil, Gas, and Coal Can Protect Communities,” April 13, 2021, https://www.greenpeace.org/usa/reports/fossil-fuel-racism/.
 Polyurethanes are based on isocyanates, which are asthmagens, and epoxies rely on chemicals like Bisphenol A (BPA) which is a developmental and reproductive toxicant and endocrine disruptor. See Common Products for Bamboo Flooring (engineered), Hardwood Flooring (prefinished), Heterogeneous Vinyl Resilient Sheet Flooring, Luxury Vinyl Tile (LVT), Cork Flooring (Glue-down), PVC-free Resilient Flooring (Homogeneous), PVC-free Resilient Flooring (Heterogeneous), and Linoleum Flooring.
 Lipiin Sung, Tinh Nguyen, Andrew Persily, Nanoparticle Released from Consumer Products: Flooring Nanocoatings and Interior Nanopaints Final Report to U.S. Consumer Product Safety Commission. Interagency Agreement CPSC-I-12-007. NIST Technical Note 1835. National Institute of Standards and Technology, U.S. Department of Commerce, July 15, 2014. https://www.govinfo.gov/content/pkg/GOVPUB-C13-e781c23251533ccd0d84d9bb77139438/pdf/GOVPUB-C13-e781c23251533ccd0d84d9bb77139438.pdf. See also: Tinh Nguyen, Lipiin Sung, Joannie Chin, Andrew Persily, Characterization of Airborne Nanoparticle Released from Consumer Products. Final Report to U.S. Consumer Product Safety Commission. Interagency Agreement CPSC-I-12-007. NIST Technical Note 1787. National Institute of Standards and Technology, U.S. Department of Commerce, August 2013. https://www.govinfo.gov/content/pkg/GOVPUB-C13-6f967843d67f19bf815801478ecb0eb5/pdf/GOVPUB-C13-6f967843d67f19bf815801478ecb0eb5.pdf.
 Adore Floors. “Adore Technologies.” Accessed October 12, 2021. https://www.adorefloors.com/Resources/Technologies.; True Hardwoods. “Armstrong Performance Plus.” Accessed July 18, 2016. https://web.archive.org/web/20160718013951/http://www.truehardwoods.com:80/armstrong_performance_plus.html.; Burke Flooring. “Burke Luxury Vinyl Tile Natural Wood Planks.” Accessed October 12, 2021. https://www.ecoscorefloor.burkeind.com/products-flooring-luxury-vinyl.php.; Iannoco, Louis. “Finishing the Job to Protect the Product.” Floor Covering News, July 23, 2012. https://www.fcnews.net/2012/07/finishing-the-job-to-protect-the-product/.; “Teknoflor® Resilient Sheet GSA Schedule # GS-27F-0036V.” Teknoflor, n.d. Accessed October 12, 2021.
 Bennett Deborah, Bellinger David C., Birnbaum Linda S., Bradman Asa, Chen Aimin, Cory-Slechta Deborah A., Engel Stephanie M., et al. “Project TENDR: Targeting Environmental Neuro-Developmental Risks The TENDR Consensus Statement.” Environmental Health Perspectives 124, no. 7 (July 1, 2016): A118–22. https://doi.org/10.1289/EHP358.; Engel, Stephanie M., Heather B. Patisaul, Charlotte Brody, Russ Hauser, Ami R. Zota, Deborah H. Bennet, Maureen Swanson, and Robin M. Whyatt. “Neurotoxicity of Ortho-Phthalates: Recommendations for Critical Policy Reforms to Protect Brain Development in Children.” American Journal of Public Health, February 18, 2021, e1–9. https://doi.org/10.2105/AJPH.2020.306014.; Gore, A. C., V. A. Chappell, S. E. Fenton, J. A. Flaws, A. Nadal, G. S. Prins, J. Toppari, and R. T. Zoeller. “EDC-2: The Endocrine Society’s Second Scientific Statement on Endocrine-Disrupting Chemicals.” Endocrine Reviews 36, no. 6 (December 2015): E1–150. https://doi.org/10.1210/er.2015-1010.
 For more information on PFAS, see the U.S. Environmental Protection Agency (EPA) website here: https://www.epa.gov/pfas/basic-information-pfas and California’s Department of Toxic Substances Control report on PFAS in carpet here: https://dtsc.ca.gov/wp-content/uploads/sites/31/2020/02/Final_Product-Chemical_Profile_Carpets_Rugs_PFASs_a.pdf
 California Department of Public Health (CDPH) Standard Method for Testing and Evaluation of VOC Emissions (formerly called California 01350) uses a small scale chamber test to determine emission of VOCs from products. Results of the small scale testing are modeled to represent different real world scenarios. The most protective is the residential scenario, and this should be preferred if available. Most certifications now available are for the less protective school or private office scenarios. Programs that certify the CDPH Standard Method or a variation of the standard include the industry certifications, Resilient Floor Covering Institute FloorScore and Carpet & Rug Institute Green Label Plus, and independent certifications GreenGuard Gold, SCS Indoor Advantage Gold, and Berkeley Analytical Clear Chem.
 Capri Collections. “Declare Label: And/Or.” International Living Future Institute, April 1, 2021. https://declare.living-future.org/products/and-or.; Zandur. “Declare Label: Sustain/Flex Rubber.” International Living Future Institute, November 1, 2020. https://declare.living-future.org/products/sustain-flex-rubber.;Capri Collections. “Declare Label: Re-Tire Medley.” International Living Future Institute, April 1, 2021. https://declare.living-future.org/products/re-tire-medley.
 Cooper, Anderson. “Lumber Liquidators Linked to Health and Safety Violations.” 60 Minutes, March 1, 2015. https://www.cbsnews.com/news/lumber-liquidators-linked-to-health-and-safety-violations/.
 Broadloom carpet can contain PFAS and can also use PVC or polyurethane backings (though these backings are less common for broadloom than for carpet tiles), but broadloom does not typically contain fly ash. Carpet tiles can contain all three of the chemicals or materials of concern.
 SF Environment has set regulations on environmentally preferable carpet for use in city projects. Their requirements align well with the HomeFree criteria and go further by including additional requirements. Products meeting the SF Environment requirements would fall into the higher-ranked carpet category on our Hazard Spectrum. They have compiled lists of carpets that meet their requirements, which are a great starting point for those looking for carpets without these harmful substances. Keep in mind that for some of the carpets listed, compliance with the criteria may need to be requested. For example, for Bentley carpet tiles, the customer must request the products be made without fly ash. SF Environment notes that the lists are provided by the manufacturers and haven’t been confirmed.
 Teknoflor. “Environmental Product Declaration: Teknoflor Bio-Polyurethane Flooring,” September 18, 2018. https://s3orprodpu.origin.build/origin/100350884-teknoflor_bio-polyurethane_flooring_-_epd__september_18__2018_.pdf.
 “Benefits of Resilient.” Congoleum. Accessed June 10, 2019. https://www.congoleum.com/benefits-of-resilient/.
 Floor Covering News. “TCNA: After Decade of Growth, Ceramic Tile Market Declines in 2019,” April 20, 2020. https://www.fcnews.net/2020/04/tcna-after-a-decade-of-growth-ceramic-tile-market-declines-in-2019/.
 Tiles rated with an abrasion resistance rating of Class IV are appropriate for all residential and most commercial applications. Those with a rating of Class V are appropriate for all residential and commercial applications. “Understanding Ceramic Tile Technical Specification Charts.” Conestoga Tile, January 12, 2015. http://www.conestogatile.com/learning-center/understanding-ceramic-tile-technical-specification-charts/. and Simpson, Katelyn. “Tile Abrasion: ASTM C1027 and Possible Upcoming Changes.” TILE Magazine, October 2009. https://www.tcnatile.com/images/pdfs/Tile%20Abrasion%20-%20ASTM%20C1027%20and%20Possible%20Upcoming%20Changes.pdf.
 Environment Canada, Health Canada. “Screening Assessment for the Challenge: Octamethylcyclotetrasiloxane (D4).” Health Canada, November 2008. https://www.ec.gc.ca/ese-ees/default.asp?lang=En&n=2481B508-1.
 In addition to HBN’s report on Avoiding Contaminants in Tire-Derived Flooring linked above, see the following report for additional information on potential contaminants in crumb rubber. “Athletic Playing Fields: Choosing Safer Options for Health and the Environment.” Toxics Use Reduction Institute (TURI): UMass Lowell, April 2018. https://www.turi.org/TURI_Publications/TURI_Reports/Athletic_Playing_Fields_Choosing_Safer_Options_for_Health_and_the_Environment.
 Public Health Institute. “Tire-Derived Rubber Flooring Chemical Emissions Study: Laboratory Study Report.” CalRecycle, October 2010. https://www2.calrecycle.ca.gov/Publications/Download/929.
 Blum Arlene, Balan Simona A., Scheringer Martin, Trier Xenia, Goldenman Gretta, Cousins Ian T., Diamond Miriam, et al. “The Madrid Statement on Poly- and Perfluoroalkyl Substances (PFASs).” Environmental Health Perspectives 123, no. 5 (May 1, 2015): A107–11. https://doi.org/10.1289/ehp.1509934.
 “Health Concerns about Spray Polyurethane Foam.” Overviews and Factsheets, US EPA, OCSPP, https://www.epa.gov/saferchoice/health-concerns-about-spray-polyurethane-foam.
Last updated: December 23, 2021