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Did You Know?
One of the most toxic things about counter tops is not the materials but the sealants. Stone countertops are often sealed with toxic fluoropolymer (Teflon™-like) chemicals to protect them from stains.
Laminate countertops can emit Volatile Organic Compounds from the glues that hold them in place. If you choose this material, purchase counters from the factory that are pre-glued. Some or most of the emissions will be discharged there instead of in your home.
Vinyl overlays are sometimes pasted over existing counters to mask damage, but these contain phthalates and catalysts that can be toxic.
Many consumers believe antimicrobial countertops kill food-borne bacteria. But some of the bacteria will survive and mutate to resist these very chemicals.
Kitchen & Bathroom Surfaces
Countertops have both direct and indirect effects on the indoor environment. Products manufactured with certain chemicals can offgas VOCs into the air, and toxins coating them or embedded in them can sluff off over time through wear and washing. Most stone surfaces are treated with protective sealants, which can be toxic. Poor quality products (that are not easily repairable) also need replacement or refurbishment; such construction creates a different kind of indoor air quality problem.
According to a market share report by the Freedonia Group, in 2019, 97% of the 27 square miles of countertops installed in the U.S. were made from 5 generic materials: tile; engineered stone; natural stone; acrylic solid surfaces; and laminate. The remainder are specialty products that are purchased for the style, or because they are low-cost.
This article attempts to rate generic classes of countertop surfaces. There are many different products and sub-classes, so these ratings should be considered a general guide. For example, while most quartzite and granite surfaces are expensive, buying small amounts from “remnant” retailers can greatly lower the price. And while most quartzite and granite require sealing, some types are denser and less porous, so sealing is not as critical.
However, with the exception of soapstone, most stone surfaces are porous and very prone to staining. For this reason, most people apply sealants, and many of these have toxic ingredients, including Teflon™-like fluoropolymers.
So stone as well as certain other surfaces in this chart are usually rated both green and red. They are green since they do not emit VOCs and if they use safer sealants. However, they are red if the sealants have dangerous chemicals. And like so many other chemical dangers in our home, the chemicals appear transparent, and you will never see the hazards.
Acrylic Plastic and Engineered Quartz and Marble surfaces also have a dual rating. They are green because of their low onsite air emissions and toxin exposure. However, they are yellow because of noticeable quantities of toxins used in their manufacture.
Another class of chemicals to avoid is synthetic antimicrobials. Many consumers believe countertops with these pesticides (some of which are dangerous to people in their own right) kill food-borne bacteria. But some of the bacteria will survive and mutate to resist these very chemicals.
U.S.-Made Ceramic Tiles – Domestic tile is one of the safest countertop materials. Most U.S. products do not have lead in the glazing or ceramic body. However, by one estimate, 80% of tile sold in the U.S. is imported. So looking for the country of origin cannot be taken for granted. Unglazed tiles are even better. An extra precaution in avoiding lead in tile is to avoid products containing recycled glass from old televisions (Cathode Ray Tubes, or CRTs).
Other considerations are abrasion and scratch resistance. Using higher quality products (glazed tiles with high Porcelain Enamel Institute, or PEI, rating or through-body porcelain tiles) will generally require less maintenance and replacement. Unglazed tiles may require sealing to make them more stain resistant.
Sintered Stone – This unique class of surface material began to be marketed in the early part of the 2010 decade. It is a synthetic counter made of natural minerals such as quartz, porcelain, and glass fused under high heat and pressure. Safe to the indoor environment, it is light and thin, yet can be as hard as quartz or granite. This material is highly resilient to common kitchen hazards such as staining, scratching, and heat. Brand names include Dekton and Neolith.
Natural Stone – Many stone countertops are stunningly beautiful. As a class, they do not emit noticeable amounts of VOCs, nor does their wear generally contribute toxic dust to the indoor environment. Surprisingly, though, some of these literally rock-hard surfaces are not that durable, being prone to stains, acid etching from certain foods and cleaners, scratches, heat damage, and surface wear. Some products are protected with toxic sealants. (Hence the simultaneous green and red rating.)
Stones are rated on the MOHS hardness scale. Quartzite and granite are on the high end, and are difficult to scratch. (They can be chipped though.)
Quartzite is the hardest natural stone surface available, making it slightly more durable than granite. It looks similar to certain other, less durable, materials. Given its expense, it is essential to conduct scratch and etching tests to confirm the material’s identity.
Both quartzite and granite, despite their hardness, are susceptible to stains unless sealed, especially lighter colors. Granite counters can also emit low levels of radon gas. While there is technically no safe level of radiation, the amount emitted to indoor air is extremely small. This author has never seen a health advisory specific to granite. However, in regions of the country where natural geology sometime creates noticeable amounts of radon in buildings, countertop emissions can add to the health burden.
Marble, limestone, and travertine (a variation of limestone) are all surfaces whose beauty outshines their durability. They are all relatively soft, so are prone to scratching. They are extremely vulnerable to stains and acid etching, including foods such as vinegar, citrus, and tomato sauce. They are more suited to bathroom counters than kitchens.
Soapstone is generally the only natural stone counter surface that does not need sealing to protect from stains. However, since it colors unevenly overtime, some owners of these counters prefer to periodically cover it with mineral oil to create a uniform appearance. It is much softer than many other surfaces, and quite prone to scratching.
Acrylic Solid Surface – Counters made of acrylic or polymethyl methacrylate are solid sheets of non-stainable plastic. They are impervious, so no sealant is required. While containing toxic chemicals, they are embedded in the material or emitted at the factory. They are generally not released into the indoor environment.
Engineered Quartz / Cultured Marble – Engineered quartz counters (differing from quartzite) employ quartz and other minerals pressed under high heat and vacuum. Minerals make up the vast majority of the product. The toxic resin typically makes up only about 6% of the material. Cultured marble is largely made up of ground limestone molded together with polyester resin and decorated with swirled pigment to resemble marble. The resin typically makes up about 20% of the material.
Like acrylics, the chemicals are embedded in the materials or emitted at the factory. Their impervious quality makes them stain resistant, eliminating the need for sealants.
High Pressure Laminate – This class of counters employs resin-coated paper pressed under high heat to form a solid surface. Melamine resins are used in the decorative top coat, and phenol resins are used in the underlying base. The material sometimes has aluminum oxide added to it for extra wear and impact endurance. Laminate surfaces are applied on top of a (usually wood-based) substrate.
The resins can emit formaldehyde and other VOCs, though many laminate counter products are rated for low emissions. An added concern is that laminate sheets applied in buildings must be glued down, and these glues can also emit VOCs. This concern can be mitigated by purchasing laminate counters pre-glued at the factory, where some of these VOCs are discharged.
Ceramic Tiles/Imported or With Recycled CRT Glass – Imported tile is more likely to be glazed with heavy-metal pigments such as lead, which can eventually wear away and get into the indoor environment. The same problem can exist in tile where recycled lead glass from CRTs is used. Do not use imported tile or tile made with recycled glass unless the ingredients can be sourced.
Vinyl Film – Adhesive-backed vinyl is sometimes pasted over existing counters to mask damage or to get a new appearance at a low price. As with other vinyl products, the material is toxic to manufacture, and may include hazardous phthalates and catalysts.
Other Counter Surfaces
Linoleum – This is the same wear-resistant material used for floors. It comes in hundreds of colors and patterns, and is inexpensive compared to most other counter materials. It is also naturally antimicrobial (without the use of biocides). However, it is vulnerable to scratches and heat.
Stainless Steel – This counter material casts a cold look, but some people want this for a modern style. While it has a positive effect on the indoor environment, many steel counters do not hold up well to scratches.
Recycled Glass – Counters made of recycled glass make a strong statement about sustainability by preventing use of virgin material. Brightly colored glass from beverage containers, stop lights, auto glass, and even stained glass are mixed in a counter slab held together with cement or epoxy resin.
Some resins contain BPA, a potent endrocrine disruptor. And even though recycled counters are relatively healthy for indoor air quality, they need to be sealed once a year to prevent staining, again raising concern about toxins in the sealant. If cement binders are used, check to assure that coal fly ash that might contain heavy metals is avoided.
Concrete – This counter class is always custom-crafted onsite. The raw materials are obviously heavy. Unless Do-It-Yourselfers have experience working with concrete, it would be best to have these created by professionals (which can add to expense). Cement containing coal fly ash with heavy metals should be avoided.
While some concrete countertops become unique art forms that cannot be duplicated with other materials, they are vulnerable to stains and must be sealed like stone surfaces. They can also chip, and develop hairline cracks.
Wood – Wooden plank and “butcher-block” countertops are made from renewable resources, and give kitchens a warm appearance. The surface can be sealed to retain moisture and protect it from stains, scratches, and heat, though some of these finishes can offgas VOCs. Further contributing to longevity, these materials are fairly easy to repair; this often is accomplished through oiling and waxing, or light sanding and resealing. Bamboo counter products are also naturally antimicrobial.
Prices range from low-cost for some domestic species to extremely expensive for exotic imports. Though finishes can make wood more resilient to water, some experts recommend its use for counters away from sink areas that are frequently moist. Flammability of wood also makes it difficult to locate near stoves. Wood hardness is not rated on the MOHS scale, but the Janka scale. (See p. 109.)
Environmental/Health Ratings for Countertops
In addition to the ranking of generic products at the beginning of this article, a few agencies and institutions have created rating systems to certify countertops.
This rating system administered by Underwriters Laboratories measures for VOCs emitted from many product categories, including counter surfaces. It has two tiers: its standard GREENGUARD rating; and its premium GREENGUARD Gold rating.
Scientific Certification Systems, Inc. is a private company now operating as SCS Global Services. It certifies third-party verifications of environmental claims, including VOC emissions from counter surfaces under its Indoor Advantage Gold program.
Safety Data Sheets (SDS)
These legally required summaries of potential product hazards are usually found on manufacturers’ Web sites. Safety Data Sheets have shortcomings. Due to trade secrets, ingredient percentages are often vague. SDS 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.