Given any of the variety of adhesive and sealant products on the market, many ASI readers could probably determine the specific VOC rule and level that would apply. Generally speaking, we know that the substrate, application method, packaging and intended market segment all play into the specific category and level that an adhesive or sealant must meet.

Some coating and membrane products, however, can be difficult to place into the right category. As the examples below illustrate, some products that are considered to be coatings may not even lie within the architectural coatings rule, but may instead cross over to adhesives and sealants rules—or even others.

A Detailing/Trowel Grade of a Waterproofing Membrane

Many cold-applied waterproofing products belong to one or more of four viscosity grades: 

• Self-leveling (SL) grades for horizontal surfaces; usually applied via squeegee or floor rake
• Roller (R) grades for vertical surfaces/walls; usually applied via a roller
• Spray (SP) grades typically for walls; sprayed on
• Trowel (T) grades for detail work around penetrations and cants; usually applied via a trowel or bulk-load caulking gun

While it depends on the geography, labeling, marketed applications and substrates, the SL, R and SP grades of these membranes are usually considered either waterproofing sealers or (waterproofing) concrete/masonry sealers. However, the so-called T grade typically is not. Because of intended use and application methodology (e.g., detail work and trowel or bulk gun), these grades are considered to be architectural sealants, and are therefore governed by sealant and adhesives rules. Depending on geography and other variables, this could mean a difference of 150 g/L in allowed VOC content.

Primer vs. Adhesive Bonding Primer

Primers generally leave behind a bonded thin film to which a subsequent material will bond. This is typically the extent of their function. They make a subsequent layer adhere better, and often feel tack-free and dry to the touch.

But what if the primer does more? If it has an inherent tackiness and actually improves adhesion, it is no longer just a primer. Instead, the product is working to make sticky stuff stick even better. Peel-and-stick or self-adhering sheet membranes used in air barrier and waterproofing applications may use this kind of primer.

While most coatings rules cover several primer categories, this type of product does not belong to any of them. Instead, the product is most often referred to as an adhesive bonding primer—a category in many adhesive and sealant rules. Again, depending on use, substrate, geography, etc., this can mean a significant difference in the allowable VOC.


Many manufacturers categorize their products incorrectly; according to some sources, roughly 50% of all coating and membrane products on the market could be miscategorized. So what can be done to ensure the best likely categorization?

The answer sounds simple: do an audit. Assemble a core team of reviewers representing legal, EH&S, sustainability and regulatory affairs. Arm the team with data sheets, labels, application instructions, the pertinent rules, and the ability to reach out as needed to marketing and technical services to completely understand substrates, uses, etc. Let the team determine the category based on their expertise and not potential dollar impact.

The team should consider several factors:

• Substrate—metal, wood, concrete, a combination of these, or other
• Purpose—decorative, waterproofing, priming
• Gloss—a product that fits no specific category may go into a default where allowable VOC level is based on gloss
• Application—many specialty applications have their own categories
• Solids—there are low-solids categories

The results may show that some products may need to be restricted in geography, application, etc. You may find some that have been overly restricted or could be recategorized into a “better” category. The audit process helps ensure compliance and gives direction for possible future product development.

The single biggest coatings slip-up is forgetting that, like many categories where products can cross many uses, these products are typically bound by the category with the strictest use. Even if the use listed on the data sheet represents a small percentage of actual use overall, your literature should reflect the strictest rules and regulations that apply.

The regulation of coatings is not too difficult to understand. A careful evaluation of rules can determine what products fall into which categories. Doing so can greatly reduce regulatory liability for manufacturers, distribution and end users, and is an excellent gap analysis for determining future product needs.

 Any views or opinions expressed in this column are those of the author and do not represent those of ASI, its staff, Editorial Advisory Board or BNP Media.