What is Ground Level Ozone?
In order to reduce the amount of ground level ozone in the air, you first have to look at the sources. One of the sources for ground level ozone is the reaction of Volatile Organic Compounds (VOCs) with Nitrogen Oxides (NOx) in the presence of heat and sunlight. This is why on hot, sunny days; communities make announcements that it is an “Ozone Action Day.” Without the help of heat and the sunlight, VOC and NOx do not react as quickly to form ground level ozone.
Once you understand the sources of ground level ozone, you must then reduce the amount of VOC and NOx in the air to eliminate the potential for creating the ground level ozone. (Eliminating the sun is not an option.) One common source of VOCs is in coatings. Coatings contain solvents to help in the application and the formation of the coating as a film. Without these solvents the coating would be very thick and the films sprayed would not be smooth.
How are refinish coatings affected?
In the automotive refinish industry, the application of coatings on a car is very critical. The finish on a repaired car not only has to match the color of the car, but has to match the texture and finish of the car being repaired. The goal in repairing a car is to return it to pre-accident condition, therefore creating an invisible repair. In order to obtain this goal, coatings must contain solvents to make the film smooth. Solvents are also critical in the application of the color basecoat in order to get the proper color match, especially with metallic colors.
So the questions to ask are:
· How do we lower ground level ozone in the air we breathe?
· How do we reduce the VOC content of coatings?
· How do we meet the performance and appearance goals of a refinish repair?
And the answers to those questions are:
· The U.S. EPA has set limits for ozone and proposes to lower this level even further.
· The air districts or states have set new VOC limits or will set new limits in the future.
· Coatings technology can meet these new VOC limits and still reach the performance and appearance goals of a refinish repair.
Changes to the VOC Regulations
The biggest change in California VOC regulations is eliminating the averaging of the basecoat and clearcoat system. In the past, refinishers were allowed to take two-times the clearcoat VOC plus the VOC of the basecoat and divide that total by three to get the average VOC of the system. These new regulations have separate categories for color coating (basecoat) and clear coatings VOC limits.
When considering compliance with these changes in regulations, switching to a waterborne basecoat system is the most logical choice. Waterborne systems use water in place of the organic solvents that were creating the VOCs. While most of the organic solvents are eliminated from waterborne basecoat systems, not all of them can be removed, so California air districts still allow 3.5 pounds per gallon VOC in these systems.
The basecoat is the most critical part in an automotive refinish repair because it is the color—and matching the color is the most important element in any repair. Extensive experience and technique are required to get the right color match with a basecoat. Temperature, humidity, type of spray gun, air pressure and air movement can slightly alter the color of a waterborne basecoat as it is applied; so it is very important to undergo sufficient training before making the switch to waterborne.
In 1992 BASF was the first company in the refinish industry to launch waterborne basecoat. In the last 16 years BASF has been able to “fine tune’ the systems to make them extremely user friendly. For instance the application methods for their waterborne system mirror those of their conventional basecoats.
BASF offers two different waterborne basecoat systems—Glasurit 90-Line and R-M Onyx HD. Both of these systems utilize a solvent-based color system that is converted to waterborne when the color is mixed. One advantage to this type of system is that the tint bases will not freeze and there are no special transportation requirements for the tint bases. Other advantages of this system are that the shelf life is several years, and the color bases are highly pigmented and in smaller containers. Thus reducing spill and waste potential and reducing storage space requirements.
Other positive attributes of BASF’s waterborne systems are that they are easy to use and the learning curve is very short. In fact, most painters require just a few hours of training in order to spray the waterborne systems just as they did with solvent-based systems.
Not only are the waterborne basecoats meeting the new VOC regulations in California, they also reduce the ecological impact that basecoat systems have on the environment. BASF performed an Eco-Efficiency Analysis of the Glasurit 90-Line waterborne system versus the Glasurit 55-Line solvent based basecoat. The analysis showed slight reduction in energy consumption, land use and resource consumption when using 90-Line waterborne basecoat. The greater result of using the 90-Line waterborne basecoat was seen in reduction of VOC emissions, health issues, and risk potential. When you combine these advantages with the other advantages mentioned above, this system is a win-win-win for the environment, for the automotive refinish industry and for society and future generations.
To learn more about the information discussed in this article, there are several informative website links listed below.
US EPA: www.epa.gov/oar/oaqps/greenbk/o8index.html