Volatile organic compounds (VOC) present multiple issues for the environment and for businesses that must control their use. Due to the hazardous nature of these compounds, several agencies place them under strict regulations. However, methods used in the past to mitigate these compounds compromised the performance of the paints or adhesives. Consequently, users increased their use of VOC-containing compounds to get better results for their products.
Today, with modern materials, VOC reduction can benefit both your business and the environment. New materials and formulation methods can reduce the VOCs in paints or adhesives while maintaining their performance. When formulating products, consider using methods to create low VOC coatings or adhesives to maintain regulatory compliance and prepare your paints, sealants or adhesives for a greener future.
What Are VOCs?
To understand VOCs, you must distinguish these compounds from other related products. Hazardous Air Pollutants (HAPs) are products that have the potential for causing cancer or other serious health issues. Within the 187 HAPs
identified by the Environmental Protection Agency (EPA), many are also
volatile organic compounds.
Volatile organic compounds have low water solubility and high vapor pressure, allowing their release as gases into the air. Thousands of products use VOCs in their creation, including dry cleaning fluids, petroleum fuels, paints, adhesives, sealants, hydraulic fluids and paint thinners.
While many HAPs impact air inside and out, VOCs typically
produce problems for indoor air quality. Inside, VOC levels can be up
to 10 times higher than outside. Consequently, controlling VOCs in paints,
adhesives and similar substances for inside use can improve indoor air quality
Some substances are exempt from regulations for VOCs because
they are not as reactive. Definitions of VOCs depend on the country, and the
United States’ list
of exempted products include:
- AMP-95 (2-amino-2-methyl-1-propanol)
- Dimethyl carbonate
- Methyl acetate
- Methyl chloride
- Oxol 100 (parachlorobenzotrifluoride)
- Propylene carbonate
- T-butyl acetate
Different countries or regions have their definitions
and means of monitoring VOCs. Often health or environmental agencies regulate the
output of these products.
In Canada, Health Canada defines VOCs as organic compounds
that can negatively impact air quality and have boiling points ranging from 50
to 250 degrees Celsius (122 to 482 degrees Fahrenheit).
The Chinese EEP defines VOCs in China as products that come
from fuel burning, oil storage and transportation, furniture coatings, cooking
oil fumes and other chemicals from civilian use, using automobiles and industrial
The European Union’s (EU) VOC Solvents Emissions Directive REACH similarly identifies VOCs as Canada does, based on the boiling point.
In the EU, VOCs are organic compounds with boiling points lower than 250
degrees C (482 degrees F) when measured at regular atmospheric pressure, 101.3
India’s Central Pollution Control Board does not
differentiate VOCs as a category. However, it does monitor nitrogen oxides
(NOx), fine particulate matter (PM10), suspended particulate matter (SPM) and sulfur
The United States also has regulations involving VOCs.
However, the specific guidelines that companies must follow depend on their
location. For instance, products made or sold in California must meet that
state’s requirements in addition to federal regulations.
U.S. Regulations Involving VOCs
Several bodies in the United States regulate VOCs. These
include the EPA, the Occupational Safety and Health Administration (OSHA) and ASTM. Many states have additional regulations for VOCs, such as California’s Prop 65. These regulators have separate requirements for controlling
VOC levels in different situations and for varying reasons. For instance, the EPA concerns itself with the environmental impacts of VOCs, while OSHA wants to protect employees exposed to these compounds. Which agencies and regulations a product or company must follow depends on the situation.
The EPA’s focus on regulating VOCs comes from their ability
to generate photochemical smog when they react with nitrogen oxides and sunlight. The
requirements for VOC levels and control are outlined in 40
CFR 59. This regulation separates various requirements for consumer products,
architectural coatings, automobile refinish coatings, aerosol coatings and fuel
containers. Legal guidelines within each category outline how producers must
keep records, labels and reports on the VOCs in their products.
OSHA protects worker health for those in office buildings,
manufacturing facilities and everywhere else. By regulating levels of VOCs that
workers have exposure to, the agency prevents short and long-term health
problems caused by these substances. OSHA publishes tables of permissible exposure
limits of VOCs and other substances that compare its requirements to those
of other agencies. These tables serve as a good reference for anyone seeking compliance
with OSHA and other regulatory agencies.
Once known as the American Society for Testing and Materials, ASTM creates technical standards used in the United States and worldwide. These voluntary standards cover processes, products, services and materials, including VOCs.
The standard governing testing of VOCs in water-based
coatings is the ASTM D6886. Unlike other standards, this one only describes how
to test for VOCs in paints and other coatings. By using this method, companies
can determine whether their products fall within other agency regulations.
California Prop 65
California Proposition 65, passed in 1986, does not prohibit VOCs or regulate their acceptable levels. This law requires products containing any chemicals known to cause birth defects or cancer to warn those exposed to the chemicals. Warnings can take the form of labels, workplace signs or newspaper notices. The state maintains a listing
of more than 800 chemicals that require the label if a product contains
them. This list includes VOCs and other hazardous compounds.
United States Green Building Council
The United States Green Building Council creates
requirements for VOC limits in green building construction projects. The organization outlines VOC limits for sealants,
adhesives and other substances. Structures that seek Leadership in Energy and Environmental
Design (LEED) certification need to follow these guidelines, which promote healthier,
more sustainable structures.
Why Is VOC Reduction Important?
Cutting VOCs in paints and other products benefits people in
spaces with the products, those applying the products and the environment. Air
quality improvements help the environment and individual health. Therefore, products
for both indoor and outdoor use can benefit from reducing VOCs.
Preventing Ground-Level Ozone and Smog Creation
VOCs can mix in the atmosphere with sunlight, heat and
nitrogen oxides to produce
ground-level ozone. By reducing the amount of VOCs in products during
formulation and application, ground-level ozone, which is the main component of
smog, can drop. Ground-level ozone can cause breathing problems, especially for
sensitive individuals or those with asthma. Therefore, reducing ozone makes communities
Improving Manufacturer Sustainability
Low VOC products are a greener option, improving
environmental sustainability for the companies that make them. As many construction companies and their customers seek to create greener buildings to meet LEED guidelines, they have a
demand for low VOC bonding adhesive and other building products. Companies that
create adhesives, sealants or paints to meet the green standards provide a
sustainable supply for environmentally conscious builders.
Avoiding Fines for Exceeding VOC Quotas
Staying compliant with VOC regulations can help companies avoid fines. Not having to pay fines and make corrections in production processes
will save money over time and make investing in reducing VOCs worthwhile.
VOCs can produce odors that can cause headaches, eye irritations,
nose and throat problems, dizziness or memory issues. Lower VOC products can
reduce these negative health effects and cut down on odors.
Earning LEED Credits
LEED certification for buildings is a gold standard for
sustainability. In fact, among corporate leaders, 61% believe sustainability sets their companies apart and improves their financial performance. Producers of low VOC adhesive or paint used in the construction of
LEED buildings can cater to this market.
To obtain LEED certification, building design and construction teams need to earn a specific number of credits based on sustainable materials and practices they use. With low VOC products, builders can earn credits toward their LEED certification.
Planning for Future Regulatory Restrictions
Creating low VOC paint, coatings or adhesives can improve
manufacturer competitiveness into the future. As regulatory agencies update
their requirements for VOC levels, producers who create low VOC products will remain
Solvent-Based vs. Water-Based Coatings
When comparing water-based vs. solvent-based paints and coatings, it’s important to look at both their performance and VOC content. Both water-based and solvent-based substances require caution during use and
storage because their vapors can be flammable. Solvent-based coatings remain
popular for many
projects that demand lower costs and faster drying time. However, through precise
formulation, some water-based coatings can offer the same benefits as
Solvent-based coatings use a solvent to hasten drying time. The
solvent reacts with oxygen to evaporate into the air. While this evaporation
releases VOCs, it also allows for drying in humid environments that would prohibit
proper drying of water-based paints.
Solvent-based paints also have the advantage of protecting
against corrosion on surfaces susceptible to water damage. Consequently, many
industrial coatings use solvent bases. Plus, solvent-based products cost
less than water-based ones.
The low VOCs and HAPs of water-based coatings mean they are
a greener option than solvent-based paints. Water-based coatings can work well for
indoor applications where VOCs can build and cause breathing problems. Many
interior paints and adhesives use water for their bases.
The downside to water-based paints is their need for
specific humidity levels and temperatures to ensure proper drying. Some high-humidity
environments will not allow these paints to correctly dry, leaving the surfaces
tacky or the finish uneven.
Though the surfaces on which they are used require preparation
to ensure proper adhesion, water-based paints have more applications than
powder-based coatings or solvent-based paints. For many, overcoming the minor
issues affecting adhesion is an acceptable trade-off for using a greener
alternative that helps them to avoid fines for exceeding VOC levels.
Modern chemical engineering allows for water-based paints to
have similar benefits that were once only found in solvent-based coatings. For
instance, proper engineering can permit water-based paints to have UV
resistance, moisture repellence and abrasion resistance.
Difficulties With Powder-Based Coatings
Powder-based coatings are another alternative to liquid solvent
or water-based options. Due to the method of application, these coatings are
much more efficient. What makes powder coatings different is their solid state.
The solid powder, though, requires high temperatures to cure. However, it does
not release VOCs as solvent-based paints do.
Several difficulties prohibit the use of
these coatings for universal coverage of surfaces. In fact, while powder-based
coatings perform very well where appropriate, they have a very limited range in
what they can do.
Need Substrates That Can Handle High Temperatures
First, any substrate that has a powder-based coating applied
must have the capacity to withstand high temperatures. After the application of the
powder, the surface requires heating to melt the powder, which allows it to
thermoset into an even layer of color. Temperature-sensitive substrates cannot
accommodate the high heat of powder coatings.
Only Permits One Color at a Time
While water-based paints and coatings permit color changing
and matching during the application, powder coating requires pre-tinting before application.
Plus, powder coating can only apply one color at a time and requires curing between
colors. For multicolored surfaces, the time required for powder coating may
High Financial Requirements for Application
The most severely constraining issue with powder coating is the
investment required for application. While small projects are easily painted with
a water-based coating, powder coating requires time, equipment and space that
makes small projects not financially feasible. Most facilities that provide
powder coating do so for large orders to offset the investment required.
Issues That Affect Water-Based Coating Adhesion
Getting water-based coatings to adhere to surfaces can be difficult due to several issues. However, overcoming these problems can make using water-based paint possible, especially with less porous and harder-to-coat plastics.
Lack of Wetting Agents
Solvents dry faster because the liquid solvents evaporate
and leave the pigment adhering tightly to the surface. The chemistry of the solvent
wets the surface, which allows the pigmentation to directly contact it.
Water-based coatings, however, create tiny beads of water
containing the pigment. These beads don’t dry quickly and suspend the pigments
above the surface. To improve the performance of water-based paints, wetting and
foaming agents prevent beading and help the pigment to contact the surface.
Using the wrong wetting agents can have issues, though. Improperly matched agents may prevent the full adhesion of the coloring to the surface. Defoaming agents intended to prevent beading can also prevent the coating from creating a smooth surface. Choosing proper agents for wetting and defoaming to pair with the substrate and components of the coating will ensure proper adhesion of the paint while avoiding some of the disadvantages of these additives.
Powdering Out Due to Improper pH
Regulating pH is important for the adhesion of paints and coatings. Formulators may use ammonia to raise the pH of water-based coatings. The downside to this product is the faster evaporation rate of ammonia compared to water. When the ammonia evaporates out of the paint as it dries, the pH of the coating drops. Consequently, the coating may “powder out” due to the excessively low pH. This prevents the coating from properly adhering to the surface.
Water Evaporation and Higher Energy Requirements
Water-based coatings need low humidity and high heat to dry quickly. Solvent-based coatings don’t require special environments to dry properly. Coaters may need additional energy to create the desired warmth and low humidity for the water to evaporate faster. In some cases, bringing in dehumidifiers can increase the energy required, raising the overall total cost.
Needing Surfactants to Overcome Water’s High Surface Tension
Water has high surface tension. The surface tension of any
coating needs to be lower than the value of the surface. The problem with
water-based coatings is the high surface tension of water.
Lower surface tensions allow for better dispersion of ingredients
in coatings and adhesion of those to a substrate. To make water-based paints accept
additives, such as UV absorbers, they need soaps to break their surface tension.
These additives help the ingredients to spread evenly throughout the coating.
Plus, they help the coating stick to the surface.
How to Reduce VOCs in Coatings and Adhesives
To reduce volatile organic compounds in paints, coatings and
adhesives, you can use several strategies. Application methods can
reduce VOCs released from paints. Plus, formulation methods that balance
specific benefits of the product with VOC allowances can also mitigate VOC
At the Application Level
When applying paints, spray painting a surface can release extra VOCs
from overspray. To reduce the VOCs released, choose more appropriate spray-painting
methods that reduce the wasted paint.
Transfer efficiency is the key to cutting VOCs. The higher the
transfer efficiency, the more paint reaches the target surface. High transfer
efficiency reduces the VOCs that painters expose themselves to by cutting the amount of
paint that does not cover the target surface. Plus, it will reduce wasted paint
and extend the lives of the painting booth filters.
Using automation technology to apply spray paint improves transfer efficiency and requires less paint. The precision of robots ensures
the optimum amount of paint used for coating while cutting waste.
At the Formulation Level
Even more important than cutting VOCs during application is formulating paints with lower VOC amounts. However, the VOC content often comes from solvents necessary for obtaining desired properties from the paint. You can use a few strategies to include these ingredients in the paint while reducing unwanted compounds.
First, consider switching to low VOC solvents. These solvents have lower amounts of VOCs. Some coating formulations use both water-based and solvent-based parts, which reduces the overall VOCs while getting some benefits of solvent-based components.
Another option is choosing specific criteria for the final product and choosing ingredients that meet those while limiting the amount of VOCs they contribute. For instance, when creating UV-resistant paint, look for UV-resistant additives that meet or exceed VOC requirements.
Finally, explore alternatives to high-VOC products by considering water-based solvents. These use water to carry the components instead of higher VOC-containing solvents. Additives to the water-based paint can improve its properties such as flow and thickness to create similar performance levels as solvent-based paint.
Contact Active Minerals International (AMI) About Our Mineral Solutions for Water-Based Adhesives,
Paints and Sealants
At AMI, we provide mineral solutions that can help reduce VOC content in paints, sealants and adhesives. For example, our solutions for water-based adhesives include MIN-U-GEL® 400 and ACTI-GEL® 208 gel-quality attapulgite products. Depending on how they are used, MIN-U-GEL 400 and ACTI-GEL 208 can improve the properties
of flow & leveling, stability and thickness for water-based solutions. Including MIN-U-GEL 400 and ACTI-GEL 208 products in your formula may allow you to extend the applications of water-based paints, replacing solvents and reducing VOCs.
Contact the team at AMI to find out
how to learn more about these mineral product options to improve the performance of your sealants,
paints, adhesives and coatings.