Graphic Art by Scott Van Osdol using Cotton Grass by Norikazu and Bedroom by Antoha713 from Shutterstock.com
Did You Know?
- Carpet and vinyl flooring make up almost three-quarters of flooring sold in the U.S. The effects on the environment to both indoor air quality and pollution from manufacturing are quite pronounced compared to other product classes.
- The health effects of floor materials on children can be particularly magnified since they are closer to the ground and spend so much time playing there.
- Natural (non-vinyl) linoleum is made of renewable or abundant materials. Besides being attractive and long lasting, it has the uncommon characteristic of being antimicrobial, not because of added pesticides, but because of the oxidation of certain ingredients that starve microbes of oxygen.
- Cork has about 200 million air pockets per square inch, in a sense allowing people on its surface to “walk on air.”
- Wood floors that are finished at the factory are better for indoor air quality than floors finished onsite. Volatile Organic Compounds from the coating are greatly reduced.
Flooring Materials & the Environment
The Underlying Hazards
According to a 2018 survey printed in Floor Covering Weekly, 854 square miles of flooring material was sold in America. Floors rate among the worst building materials for the potential to cause environmental problems linked to indoor air quality and direct exposure to embedded toxins.
As a class, carpets and rugs had 48% of the floor market, followed by PVC vinyl with a 24% share. These two generic materials host a number of health and environmental concerns. Even more benign materials such as tile, wood, and laminate, can be problematic under certain conditions.
There are thousands of different floor products, and each has its own environmental impact. However, as generic class floor types, the chart on the right rates each product for its relative health effects inside buildings.
Carpet (including rugs) is the most popular, and problematic of all domestic flooring materials. About 410 square miles of it was installed in the U.S. in 2018, and it represents about 48% by area of the total U.S. flooring market.
On the positive side, its acoustic qualities create quieter buildings, its soft surface makes walking and standing less stressful, and it cushions falls, a big plus for small children.
However, these good attributes are outweighed by the material’s many detriments. To begin with, most carpet is derived from petrochemicals. It is very difficult to keep clean for any length of time due to the astounding number of permutations in each strand of fiber. It often absorbs or contains dust, dust mites, allergens, mold, mildew, and chemicals tracked in from the outdoors. To remove these, carpet sometimes requires special cleaning beyond what a vacuum cleaner can accomplish, and this cleaning is often enhanced with toxic chemicals.
Many brands of carpet also have short service lives compared to more durable floor surfaces. While the low cost of installation may seem attractive in the near term, other flooring materials that are long lived will save time and money in the long run.
If these reasons are not enough to avoid carpet, consider that most products on the market today are manufactured with highly toxic chemicals, literally from top to bottom. And since babies and small children spend much of their time on the floor or closer to the floor than adults, they are more likely to be exposed by direct contact and respiration.
Conventional Carpet Chemicals
Antimicrobials such as formaldehyde, a carcinogen and asthmagen, or triclosan, an endocrine disruptor and environmental toxin, are employed to keep both the fibers and carpet backing from breaking down. Some products use nano-silver as a biocide, whose safety is largely untested.
“Fly ash” from coal combustion is used as a filler or bulking agent in carpet backing, which contains the toxic mineral asbestos and the toxic heavy metals cadmium, lead, and mercury. These can collectively contribute to a number of adverse health problems including cancer, childhood development problems, and neurotoxicty. (Ironically, as coal-plant scrubbers improve their ability to clean the air, they collect more toxics that are often recycled into carpet.)
Flame retardants are found in carpet fibers, backing, and cushioning. While flame retardants can be mineral-based and without major health affects, some can be toxic. These include halogenated chemicals and antimony trioxide, which are carcinogenic, developmental and reproductive toxins, and endocrine disruptors.
Carpet backing is usually toxic in its own right. Backing materials include polyvinyl chloride (PVC), polyurethane, and styrene butadiene (SB).
• Polyvinyl Chloride (PVC) is the most toxic of common plastics. It is an organochlorine, in the same carcinogenic chemical family as dioxin, DDT and PCB. Organochlorines are released in its manufacture, as well as in accidental building fires, landfill fires, and during waste incineration. The production process also releases considerable amounts of asbestos.
• Polyurethane is partially made up of isocyanates, a very potent asthmagen.
• SB backing contains styrene (carcinogen and asthmagen), and butadiene (carcinogen and developmental toxin). To produce styrene, ethylbenzene, another carcinogen, is released.
Organotins are organometallic substances used as stabilizers and catalysts in the manufacture of carpet backing. Their dangers include reproductive toxins, endocrine disruptors, mutagenicity, eye and skin irritation, and organ toxicity.
Phthalates are used as plasticizers in backing to make carpet flexible. While their danger depends on the specific chemical used, some of them can cause asthma, cancer, and reproductive and developmental harm. While phthalate chemicals are being phased out of many new products due to consumer demand for safer materials, carpet backings in products sold prior to 2015 could well include them.
Carpet cushioning is also problematic. Since it is usually made with recycled furniture cushioning, the flame retardants in it are transferred to the new cushion.
Carpet adhesives, most commonly used on broadloom carpet found in residences, can contain carcinogens, endocrine disruptors, and developmental toxins.
Volatile Organic Compounds (VOCs) are offgassed chemicals from carpet materials that adversely affect indoor air quality. Short-term effects can be severe enough to cause allergic reactions, dizziness, nausea, and headaches. Long-term exposures can be linked to cancer, organ toxicity, and even birth defects at high levels. While most VOCs from new carpet are discharged within a few weeks after installation, low-levels of emissions can continue for years.
And do not forget the chemicals in these carpet shampoos. Though it is possible to find commercial and home made products that are relatively benign, many cleaners today have ingredients that are acutely toxic, asthmagenic, toxic to the respiratory tract, carcinogenic, and developmental/reproductive toxins.
There are numerous ways that these toxins are released or shaken from the original carpet and introduced into the indoor and even outdoor environment. Some are emitted as Volatile Organic Compounds. Others are quickly or slowly broken loose through the force of installations, foot traffic, and cleaning. Over time, carpet can also degrade from oxidation, biodegradation, photolysis, and hydrolysis. The toxic molecules appear in house dust, and even in water used for carpet shampoos, which is eventually discharged to the sewer system into the environment.
Carpet manufacturers have adapted new materials and chemical ingredients to reduce or eliminate toxic chemicals for the various parts of the carpet. It is quite possible to buy carpets with several of these more benign materials and technologies in the same product. It may, however, take some shopping to find carpets that include most of them. Below are a few alternatives.
Carpet Fiber: Safer stain resistors are in various brands including Aquafil Econyl StayClean, United Fibers sulfonated nylon copolymers, and Invision Fluorine Free repellent.
Carpet Backings: Various companies now make products with less hazardous backing materials.
• Shaw Direct’s Ecoworx®, Mannington Commercial’s rEvolve™, and Mohawk Group’s EcoFlex NXT™, use polyolefin backing.
• J+J/Invision’s eKo® Modular backing uses polyethylene.
• Tandus Flooring’s ethos® modular uses polyvinyl butyral (a distinctly different chemical than polyvinyl chloride).
Fire retardants: Alumina trihydrate (ATH) is mineral-based and fairly benign, and is often used instead of toxic halogenated fire retardants. Mineral-based fire suppressors are actually more common than halogenated ones, so they should not be difficult to find.
Recycled Glass Filler: Shaw carpet now uses post-consumer glass as a filler instead of fly ash in carpet backing.
Carpet Padding: Alternative padding includes rubber, flexible polyurethane foam, felt, wool, and cotton. Foam with recycled content might contain halogenated fire retardants and should be avoided.
Adhesives: A few adhesive products are biobased. Many more are manufactured to low-VOC emission standards. Adhesives can be eliminated altogether by laying carpet on tacking strips. See the Floor Adhesives pages (112-113) in this section for more on this subject.
Even if all toxic chemicals are removed though, carpet will still be difficult to clean, and still harbor pollutants tracked in from the outside.
Organic Carpet Materials
Natural materials can replace petrochemical-based carpet. Again though, carpet of any kind will still be more difficult to clean than smooth flooring, and can still harbor pollutants, dust mites, and allergens tracked in from the outside to some degree.
Wool is the most common organic carpet material, making up about 2% of all carpet sales nationwide. In addition to being organic, soft, and biodegradable, it is resistant to mold and mildew, naturally stain resistant, naturally flame resistant, and can trap allergens until the carpet is cleaned. While highly durable, it is often treated with moth-repellent, which can cause reactions to people who are chemically sensitive.
Seagrass is harvested from reeds grown in saltwater paddies in China, and woven into comfortable durable carpets or rugs. Its nearly impermeable surface makes it resistant to dirt, stains, and discoloration, but it is also resistant to dyes, instead having an earth-color appearance.
Sisal is made from the interior fiber of agave plants from Brazil, Africa, and other tropical climates. It can be dyed and woven into a wide variety of textures.
Jute is derived from an Asian plant, and is one of the softest, but least durable, of natural carpet fibers. This makes it more suited to low-traffic uses such as bedrooms.
There were 207 square miles of vinyl flooring sold in the U.S. in 2018, representing 24% of the U.S. floor market. While vinyl is smooth and does not have the same cleaning problems as carpet, it is still far from an environmentally preferable alternative. It is also derived from petrochemicals, and as stated previously, polyvinyl chloride (PVC) is the most toxic of common plastics. It is one of a family of “organochlorine” chemicals that combine chlorine and carbon. These are rarely found in nature by themselves, and can take hundreds of years to biodegrade.
The manufacture of PVC is highly polluting to the surrounding environment. The most dangerous contaminant emitted is dioxin, a carcinogen, neurotoxin, reproductive toxin, and endocrine disruptor. Dioxin is also released from the material in the event of accidental house fires, as well as from unintended landfill fires and waste incinerators after disposal.
PVC factories often use toxic mercury or asbestos as part of their process.
About 70% of all PVC in the U.S. and Canada is used in buildings, and can cause potential harm to occupants. Some PVC building products are more stable than others. For instance, modern vinyl windows (as distinguished from older vinyl windows) may emit small amounts of VOCs, but are not considered nearly as unstable and toxic as PVC flooring.
As much as 50% of vinyl flooring is made up of plasticizers. Until recently, most of these were orthophthalates. While their danger depends on the specific chemical used, some of them can cause asthma, cancer, and developmental and reproductive harm.
Phthalates have been associated with increased asthma and allergies in children, as well as long-term chronic disease.
A Swedish study showed increased levels of phthalates in children living in homes with vinyl floors, leading to assumptions that they had been ingested through breathing and contact with skin. (Indoor Air, June 18, 2012, pp. 32-9.) Another Swedish study linked increased incidence of autism to vinyl flooring. (Neurotoxicology, September 2009, pp. 822-831.)
These chemicals are often being replaced with less toxic plasticizers, some made from plant materials. However, the replacement is not universal, and not all replacement plasticizers are completely benign or thoroughly tested for their effects on people and the environment.
Organotins are organometallic substances used as stabilizers in vinyl floors. While less toxic than the lead and cadmium they replace in legacy products, their dangers include reproductive toxins, endocrine disruptors, mutagenicity, eye and skin irritation, and organ toxicity.
Vinyl floors can also include flame retardants and anti-microbial chemicals similar to those in carpet. While vinyl floors are not a preferred alternative, there are ways that their hazards can be reduced.
Vinyl Floors with Recycled Content: While recycling vinyl floors may sound like it yields environmental benefits, it is actually something to be avoided given the dangerous ingredients in legacy products. Older vinyl can include lead and cadmium stabilizers, PCB (another dangerous organochlorine), antimony trioxide flame retardants, and antimicrobials such as triclosan and OBPA. The trade-off of one environmental problem for another is not worth it.
Vinyl Floors With Less Vinyl: Though a huge number of products contain vinyl, total content can range from less than 1% to as much as 75%. Obviously, less is more from an environmental standpoint. Much of the balance of ingredients in products with low percentages of vinyl is from minerals such as limestone dust (calcium carbonate).
Vinyl Floors with Least-Toxic Chemicals: Seeking out products without orthophthalate plasticizers, organotin stabilizers, toxic flame retardants, and antimicrobials will limit their exposure to the indoor environment. Look for specific preferable phthalate replacements that are better for the environment and healthy building environments: Ecolibrium (Dow); Grindsted Soft-n-Safe (Danisco/DuPont); and Polysorb ID37 (Roquette).
OTHER RESILIENT FLOORING
RESILIENT: NATURAL LINOLEUM
The term linoleum is commonly confused with vinyl. But before there was vinyl flooring (made popular after W.W.II), there was natural linoleum (invented in about 1860). It is a smooth-surface flooring material made with renewable or abundant materials such as linseed oil, tall oil rosin, pine-gum rosin, wood flour, cork and limestone powder, and jute backing.
Linoleum is generally higher cost than most vinyl products, but long lasting, and often requires less maintenance than vinyl flooring, thus reducing maintenance costs. It comes in a wide variety of colors, and the pigments go through the entire material, so that damage from scratches is not as apparent.
It is also naturally antimicrobial because the oxidation of linseed oil and pine rosin continues for the life of the flooring, starving microbes of oxygen. Because of this, linoleum is particularly valued in the healthcare industry.
Cork is similar to wood; in fact, it is made of the bark of cork oak trees harvested every 7 to 10 years, and that typically live for 250 years. It is rapidly renewable and highly durable. Since it has 200 million closed air pockets per cubic inch, it is prized for its acoustic ability to render a room quieter while insulating temperatures. In a sense, it also allows people to “walk on air,” making it comfortable for adults to stand on while soft for children to fall on.
Cork can be grown in the U.S., but currently most/all cork flooring is imported from Portugal and Spain.
Within this floor class, two main environmental considerations have indoor air quality ramifications.
Cork That is Prefinished: Some cork products come prefinished. Cork with no onsite finish has very low VOCs. Depending on the finish, some cork products are extremely resilient, and the color goes through the material, making scratches less detectable.
Cork Finished Onsite: Just like wood, adding chemicals onsite can cause VOCs to offgas, though they will diminish over time. However, many cork products require another topcoat floor finish or wax for more protection, or to make sure that spilled liquids do not creep into the cracks in cork floating-floor planks.
RESILIENT: BIOBASED AND NON-VINYL SMOOTH FLOORING
However, the biobased products sometimes also use petrochemicals that are toxic. Therefore, it is difficult to rate these products as a class. On the whole though, these are probably less toxic than vinyl smooth flooring.
One example is Armstrong’s product line – Migration™, Biobased Tile™, and Striations™ – with Biostride™ polyester derived from corn to bind limestone powder together into tile. It appears that the small percentage of the product that is made up of petrochemicals is biodegradable and relatively harmless to people.
Another example is Mannington’s Enlighten, a rubber composite with some biobased content, though a greater percentage (non-vinyl) petroleum content.
Non-Vinyl Petrochemical Smooth Flooring: There is also another option that is less environmental than biobased floors but safer than vinyl, which is smooth flooring made with less-toxic petrochemicals. While preferable to vinyl, some products still contain toxic chemicals that make them regrettable substitutes.
Rubber flooring is a very niche market at this time. The rubber can be natural or synthetic.
Its advantages include a comfortable surface for people to walk on (and children to fall on), ease of cleaning, slip-resistance in wet areas, stain-resistance, high durability, and in the case of rubber tiles, their natural tackiness can sometimes eliminate the need for adhesive installations. Unlike most other types of smooth flooring, it has sound-calming characteristics.
As with other generic classes of floors, there are various options that are more environmental than others.
Natural Rubber: Tiles made entirely of natural rubber and minerals are preferable to synthetic rubber. “Au natural” by Allstate Rubber is one such product. Note that about 4% of the general population is allergic to natural (latex) rubber. (“Current prevalence rate of latex allergy,” Journal of Occupational Health, March 20, 2016, pp. 138-144.)
Rubber Flooring With Recycled Material: The dark side of recycling tires is that toxins in them, such as lead, hydrocarbon processing oils, and carbon black, show up in floor materials and playscapes that use their “crumb rubber” feedstock. This flooring option is highly discouraged both indoors and outdoors.
Wood is a smooth, easily cleaned floor from renewable resources. Though minimal amounts of VOCs can be emitted from the wood or adhesives used to install it, wood can often be installed with non-adhesive methods (e.g., nailed and floating).
There are several categories of wood-flooring products that rank in order of environmental preference.
Solid Wood That is Prefinished: Solid wood floors have no chemical binders that offgas VOCs, so they are the environmentally preferred choice for wood. Wood floors generally need to be finished. If this is applied at the factory, most of the chemical offgassing will have taken place before it is even installed.
Engineered Wood That is Prefinished: Engineered floors can also be finished off-site, though many engineered products use chemical binders to hold wood layers or cellulose powder together, which offgas over time even if the floor finish does not.
In choosing engineered wood, the first preference is products that use resins that are soy-based or that contain no formaldehyde in the binders. Products with low formaldehyde and its attendant VOCs fall next in line. Numerous products are rated for this quality by the California Air Resource Board and the Composite Surfaces Association. (See the Sidebar on the Composite Lumber page (114) of this section for Web addresses.) Lowest ranking are floors with standard formaldehyde content and emissions.
Engineered Wood Finished on Site: This choice requires onsite use of offgassing floor sealants, and it will also offgas VOCs in the chemical binders. It is the least-preferable option for wood floors. If this option is chosen though, choosing finishes with no- or low-VOC emissions and flooring with no- or low-formaldehyde binders is preferable.
Other Environmental Concerns for Wood Floors
While floor life and the use of threatened resources do not generally impact exposure to toxins in buildings, they do affect sustainability and should be considered.
Wood Rated for Hardness: Different species of wood have different levels of hardness, and are thus more or less resilient to foot traffic, dents, and other kinds of wear. Different species are rated by the Janka hardness scale, with imported iron wood at the top and pine and cherry at the bottom. Quality is one factor that should be considered during purchase. The chart shows the Janka scale for some popular wood species. It does not include “fossilized” flooring with compressed wood, which can be rated as high as 5500 on the scale.
Wood That is Sustainably Harvested: Though wood is a renewable resource, abusive forestry practices such as clearcutting, overharvesting, harvesting too close to watersheds, and incursions into old-growth forests all cause unacceptable levels of environmental harm. Since the 1990s, wood building products have been certified for environmental harvesting standards by various third-party companies or organizations.
One of the more highly respected is the Forest Stewardship Council, which maintains lists of both companies that manufacture building materials with sustainable wood and U.S. suppliers of these companies’ products. These can be downloaded at the organization’s Web site: us.fsc.org
There are also species of trees (most of them tropical and from other continents than North America) that are endangered from over-harvesting and should be avoided. Several non-profit organizations have compiled lists of endangered tree species whose sales should be, or are, banned or controlled.
One of these is the Convention on International Trade of Endangered Species (CRITES), an organization based on international agreement between most of the world’s countries to regulate sales of wood from these species.
Banned or regulated species that CRITES has determined are threatened with extinction or whose trade must be regulated to ensure survival include: 24 species of rosewood; 5 species of Asian yew; 3 species of mahogany; 3 species of agarwood; and 3 species of bubinga. A complete list can be found at the U.S. Fish and Wildlife Web site: fws.gov/international/plants/current-cites-listings-of-tree-species.html#2
CERAMIC TILE & STONE
Common tile is typically derived from abundant and relatively safe minerals such as clay, calcium carbonate, feldspar, quartz, silica, and talc. Its kilning process renders the ingredients inert. The smooth surfaces are easy to clean. Tile emits no VOCs, though some grout/adhesives that are used to install it can. Cut stone also has these traits.
On the negative side, tile and stone can be slippery when wet; it is rated on a slip-resistance scale of 1 to 10, with 10 being the least slippery. Products used for slip resistance may introduce unwanted chemicals into the building. Tile is also hard to fall on, cold to walk on in winter months, and its smooth surface sometimes causes sound echo.
Most tile is relatively inexpensive, but as in most building materials, you get what you pay for.
All glazed tile is typically ranked on the PEI (Porcelain Enamel Institute) wear-rating scale of 1 through 5, with 5 being the best quality.
Porcelain tile is higher quality than ceramic tile, but also generally more expensive. It is harder and denser, and absorbs less moisture, allowing exterior use in cold climates because it can better tolerate freeze-thaw cycles without cracking. Glazed porcelain tile is more stain resistant.
Color body porcelain in glazed porcelain matches the color of the glaze to the color of the minerals underneath, so that if the glaze is chipped, it will be less noticeable. Through body porcelain in unglazed tiles not only incorporates the color throughout the body of the tile, but also the pattern, making chips and scratches even harder to detect. It does not have a PEI rating because of its high durability. However, it is more susceptible to stains.
Ceramic tiles are usually less expensive than porcelain, and easier to cut (important in DIY installations). Ceramic products usually (but not always) have a lower PEI rating than porcelain.
In addition to longevity concerns, there are two general environmental considerations when choosing tile.
Tile Manufactured in the U.S.: Tile made in this country is typically free of lead in its glazings. However, about 80% of tile in America is imported. If imported tile is purchased, it is important that it is sourced.
Tile With Recycled Content: While the use of recycled glass and ceramics in tile is usually a good thing environmentally, do not install products whose material sources are not disclosed. In particular, avoid products with recycled lead-glass from Cathode Ray Tube TVs.
Laminate flooring is usually made with a non-vinyl plastic surface that can resemble wood or vinyl patterns built on top of a wooden base. The wood is usually derived from ground up waste wood adhered with a binder.
As long as the binder emits low amounts of formaldehyde and other VOCs, non-vinyl laminate is environmentally superior to carpet and vinyl since it is a smooth floor that can be cleaned easily and does not contain PVC or other hazardous chemicals. Laminates are also intentionally designed as floating floors, so they often avoid adhesives used in installation.
Environmental/Health Ratings of Flooring
In addition to the ranking of generic products in this article, various agencies and institutions have created rating systems to judge flooring products. Below is a short list of them. Their Web sites give information on specific products that meet their criteria.
Cradle to Cradle Products Innovation Institute
This non-profit organization manages a comprehensive rating system for many products, including flooring materials. Cradle to Cradle rates on 5 criteria: Material Health; Material Utilization; Renewable Energy and Carbon Management; Water Stewardship; and Social Fairness. These separate ratings are then combined into an overall score.
This is SCS Global Services’ certification program for most smooth flooring types that limit VOC emissions. (These include: cementitious; ceramic, cork; engineered bamboo; engineered hardwood; laminate; linoleum; polymeric; porcelain, raised; rubber; vinyl composite tile (VCT); vinyl sheet; vinyl tile; and luxury vinyl tile (LVT). The certification also include floor accessories such as: adhesives; stair treads, underlayments; and wall bases.
As of the time of publication, about 7,200 products had been rated and listed on its Web site.
Green Label Plus
This standard, administered by the Carpet and Rug Institute, certifies carpet products if they do not exceed a minimum level of VOC emissions. At the time of publication, almost 500 carpet products rated by this label could be found at the Underwriters Laboratories’ Web site.
This certification is for ceramic and tile products, as well as products related to them such as grout, mortar, backer boards, and sheet membranes.
The certification is a point-based system that relies on: 1) the tile’s characteristics; and 2) materials extraction and the manufacturing process. Standards for characteristics include: the percentage of recycled content or recyclability of packaging; VOC levels; and the amount of indigenous raw materials (which limits energy and emissions from transportation). Meeting optional criteria for Solar Reflectance Index and acoustic standards also count for points.
Standards and optional points for materials extraction and the manufacturing process include: prohibition of visible particulate emissions; use of relatively clean process heating fuels such as natural gas; the use of low-NOx burners; written sustainable material procurement practices; and good practices for waste minimization, lighting efficiency, heating fuel usage, electricity consumption, water conservation, water discharge limits, utilization of renewable energy, cogeneration, and incorporating heat recovery or combined heat and power systems.
This certification system administered by Underwriters Laboratories measures for VOCs emitted from many product categories, including flooring. It has two tiers: its standard GREENGUARD rating; and its premium GREENGUARD Gold rating. As of the time of publication, there were over 11,200 products rated by the higher standard.
Safety Data Sheets (SDS)
These legally required summaries of potential product hazards are usually found on manufacturers’ Web sites. There are shortcomings for SDS information. Due to trade secrets, percentages of ingredients listed are often in vague ranges. And SDS rules only require listing of hazardous ingredients if they make up more than 1% of a product, and carcinogenic ingredients if they make up more than 0.1% of the product.
Health Product Declaration Collaborative
This non-profit member association creates Health Product Declarations (HPDs). HPDs allow product manufacturers to disclose information about the chemical ingredients of their products and associated health information that is more detailed than Safety Data Sheets. By promoting ingredient transparency and disclosure, HPDs enable consumers to make more informed decisions and motivate manufacturers to adopt healthier chemical ingredients.
HPDs of specific products can be accessed at its Web site.