Low VOC Colorants: Essential to Creating Eco-Friendly Coatings

Februar, 2020

Colorants are a key contributor to the color and performance of a coating. But what do paint manufacturers need to know about colorants to create a more environmentally compliant coating? We break it down in this post.

So What Are “VOCs” Anyway?

The acronym “VOC” stands for “volatile organic compound.” It’s a broad term that includes both compounds that are known to be harmful and ones not traditionally thought of as harmful. Believe it or not, even water technically contains VOCs.

The U.S. Environmental Protection Agency (EPA) defines VOCs more narrowly as:

“…any compound of carbon, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, which participates in atmospheric photochemical reactions.”

Many consumers associate VOCs with potential ingredients in products that may not be good for the environment, and in some cases may be considered harmful. These include:

  • Pesticides
  • Household cleaners
  • Aerosols
  • Air fresheners
  • Dry-cleaning chemicals
  • Paint thinner
  • Preservatives used in some wood products

While there is not one universally agreed upon way to even measure VOCs, there are a few dominant methods. The EPA quantifies VOCs in grams per liter (g/L). In the European Union, the Blue Angel regulations are currently set at 700 ppm (parts per million).

paint buckets illustrating low-VOC colorants

VOCs in the World of Coatings

VOC levels and their potential reduction are an important consideration when formulating coatings, colorants and their performance. Both the VOC level in the coating and in the colorants that are added to the paint influences the emission levels. They also affect the environmental impact and consumer well-being.

Because of these environmental and health concerns, many governments have enacted VOC level requirements for paints & coatings. The enforcement guidelines are strict, and getting stricter.

As a result of tightening regulations, many coatings and colorants manufacturers in all regions have been actively working to reduce them. This is part of a larger effort in the industry to create innovative and environmentally friendly products.

Bottom line: If you’re a coatings formulator, you should take a close look at the VOC levels not only contained in your products, but especially after the addition of the colorant.

Why are Lower VOC Colorants Important?

Historically, solvent and glycol-based colorant technologies contributed significantly to VOC levels in the final coating formulations. Regulations in most regions did not require manufacturers to give much consideration to VOC levels in the colorants added into their base paints at Point-of-Sale. Most now realize today’s low-VOC colorant technologies now outperform their older, high-VOC counterparts.

Formulating for Lower VOCs

If you are trying to reduce VOCs in your coatings to comply with regulations or even get a green level certification, but you add high VOC colorants to your low VOC paint, you’ve created a finished product that contains significant levels of VOCs.

High-VOC colorants effectively cancel out the benefits of low-VOC paint.

This is why, since the early 1990s, the industry leading colorant manufacturers started offering reduced VOC colorants to help minimize the contribution of VOCs to the final tinted coating.

So, if your goal is to create greener, lower VOC coatings, don’t forget about the colorants!

VOC-Level Terminology: A Misnomer

In response to growing interest in environmentally-friendly coatings and colorants, phrases have emerged using eye-catching terms to grab attention. These include:

  • No VOC
  • VOC-Free
  • Zero VOC

If VOCs are bad, shouldn’t products be free of them?

The terminology seems appealing. But the thing is, that’s really not possible.

Technically, there’s no way to have either paints or colorants that are totally free of all VOCs. Remember, even water contains compounds that are within the definition of a VOC.

Thus, these terms are inaccurate, and regulators are taking notice. Government agencies such as the Federal Trade Commission in the U.S. have been monitoring and acting on such claims in product labelling.

In some of the developing markets around the world, this terminology is still around, but it’s certainly on a swift decline. Regulatory bodies are increasing their enforcement and consumers / end-users have become more informed.

If you’re looking to source or formulate with more environmentally friendly colorants, don’t be misled by this misnomer terminology. Low-VOC colorants are now the standard globally for achieving more environmentally compliant coatings.

Factors That Affect Coating VOC Levels

Solvent, Water, High-Solids

The VOC level of a colorant is tied to its chemical makeup. Newer waterborne technology is the clear leader in today’s lower VOC-containing colorants.

Many colorant suppliers continue to offer solvent-based products that serve specific  requirements for the high-performance coatings segments, and advances in technology have provided some VOC reduction in those solvent formulations. And both high-solids and 100% solids colorants provide lower VOCs for certain Industrial coatings applications such as flooring.

Color Space

The finished paint color can have an impact on VOC levels, especially if you are not utilizing low-VOC colorants.  More saturated, deeper paint colors can require higher colorant addition levels and therefore add significant amounts of VOC. Especially when using glycol or solvent containing versions.

Conclusion

Reducing VOC levels in paint is a critical part of creating eco-friendly coatings. But to do so, you’ll need high-quality low VOC colorants to reach that goal.

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