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Did You Know?
- Polyurethane and epoxy, as generic classes, are the most hazardous of floor adhesive products because of the base chemicals and additives they contain. Avoid whenever possible.
Similar to other products with petrochemical bases, floor adhesives can offgas VOCs (Volatile Organic Compounds). Other chemicals in the product can directly harm workers and building occupants who are exposed to them. Over time, they can degrade, exposing building occupants to their dangers. (The particles attach to dust motes, and become breathable in the indoor air.)
The Chart below depicts the effect that various floor adhesive product classes have on the indoor environment.
Mechanical Installation – Often floors can be installed without any use of chemical adhesives. Nails, staples, and carpet tacks are alternatives. “Floating floors,” interlocking panels or squares held firmly in place by shoe molding at the baseboards, are also quite common.
Plant-Based – A few alternative products exist whose adhesive qualities are derived from plant-based materials. These products are preferred by people who are chemically sensitive, and they usually carry a price premium.
Peel and Stick – These solid (often acrylic) adhesives, in squares or strips, can either be factory applied to floor products or applied onsite. As a class, VOC emissions and toxic qualities are low or negligible.
Acrylic – This is the least toxic class of common liquid adhesive products. It is water-based, generally has low- or no-VOC emissions, and with exceptions, does not contain dangerous chemicals in large percentages. However, many acrylic products contain biocides in small amounts, and some specialty products contain flame retardants and antifreeze.
MS Polymers – Modified silicon polymers can adhere to flooring while creating a barrier for porous concrete surfaces, preventing wood floors or the adhesive itself from being affected by moisture. Like polyurethane, it allows wood flooring flexibility to move with changing humidity. However, it is free of dangerous isocyanate chemicals. Some MS products do contain organotin catalysts and biocides in small percentages.
Polyurethane – These adhesives are often used with wood floors because they form a moisture barrier on porous concrete while allowing wood to expand and contract with humidity. However, they contain isocyanates, which are potent asthmagens. They also often contain petroleum solvents and organotin catalysts. Though some products have low-VOC emissions, this class generally has higher emissions than other adhesive classes.
Epoxy – This class of adhesives contains a two-part formula that must be mixed onsite. It includes a BPA-based catalyst, a chemical reviled as an endocrine disruptor, which is also a developmental and reproductive toxin. These adhesives also contain nonylphenols (NPEs), with many of the same chemical dangers as BPA. In addition, NPEs are Persistent Bioaccumulative Toxins. And epoxy products contain amines, which are asthmagens.
Other Least Toxic Adhesives
The products in the chart are considered least toxic acrylic adhesives, though they are not rated by third party organizations. They are listed because they have a long-established reputation as materials tolerated by the chemically sensitive.
Environmental/Health Ratings for Floor Adhesives
In addition to the ranking of generic products, various agencies and institutions have created rating systems to judge floor adhesives. Below is a short list. Only a few were rated with these standards at the time of publication.
This rating system administered by Underwriters Laboratories measures for VOCs emitted from many product categories, including floor adhesives. 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. Its FloorScore® rating program sets limits for VOC emissions.
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.
South Coast Air Quality Management District (SCAQMD)
Compliant and Super Compliant Adhesive Products List
SCAQMD regulates air emissions in the greater Los Angeles area, including “Rule 1168” standards for VOCs from adhesives. This list of products, including floor adhesives, have exceptionally low emissions.