Air quality degradation is caused by many factors including the use of gasoline combustion engines. Although advances in technology have made combustion engines very efficient, they still emit particulate matter, carbon dioxide, nitrogen oxides and other pollutants. Some of these same pollutants, along with volatile organic compounds (VOCs), are also emitted from manufacturing processes. Together, these pollutants react with sunlight to form smog. A primary component of smog is ozone, which is helpful in the stratosphere to block harmful UV rays, but degrades air quality when formed at ground level. These impacts are particularly pronounced in urban areas with large numbers of vehicles, industrial activity, and sunny, warm climatic conditions.
As impacts to air quality arise from both manufacturing processes and the use of vehicles, Toyota has committed to continuously improve our products and the way in which we make them. Our performance against targets for vehicle tailpipe emissions and VOC emissions are described in this chapter.
Generally, government officials and auto manufacturers discuss vehicle tailpipe emission levels in the context of certification levels. In 2010, California required a manufacturer's fleet average to meet a NMOG standard of 0.035 grams per mile (gpm) for cars, and 0.043 for trucks. The federal programs in both the U.S. and Canada require a manufacturer's fleet average to meet a Tier 2 NOx standard of 0.07 gpm. A certification level is then assigned to each vehicle, depending on its emission levels. The certification levels in California are referred to as LEV (Low Emissions Vehicle), ULEV (Ultra Low Emissions Vehicle), SULEV (Super Ultra Low Emissions Vehicle), ZEV (Zero Emissions Vehicle), and AT-PZEV (Advanced Technology Partial Zero Emissions Vehicle). The federal programs refer to each incremental level as a "Bin" — numbering one through eight.
In addition to existing standards, California proposed a regulation in February 2010 for more stringent tailpipe emission standards (known as LEV III). When finalized, these regulations would require SULEV fleet average emissions performance from new passenger vehicles, phased in from model year 2014 to model year 2022.
Toyota annually complies with the state of California, U.S. and Canadian federal vehicle emission programs, and we have met the standards for the 2010 model year. (Target 10.1) We have consistently certified more vehicles than these programs mandate. All Toyota, Lexus and Scion passenger cars currently sold in North America, except for the Lexus SC 430, are rated ULEV or better. Specifically for vehicles offered in the 2010 model year, 41 percent of all Toyota, Lexus and Scion cars and 15 percent of trucks are certified to SULEV or better. Our SULEV vehicles include Toyota's Prius, the Prius Plug-in Hybrid, Camry PZEV, Camry Hybrid, Highlander Hybrid, and Lexus' RX 450h, LS 600h, GS 450h and HS 250h. In addition, Toyota's Industrial Equipment Division 8-series forklift truck, sold in Canada, voluntarily meets the 2010 California ARB standards for tailpipe emissions, and two of Toyota's vehicles — the Prius and the Yaris — are included in the list of "Greenest Vehicles of 2010" by the American Council for an Energy-Efficient Economy (please see Figure N.)
Finally, it is important to note that as a complimentary step to achieving reductions in vehicle emissions, there are state and federal efforts in place to reduce pollutants in gasoline. California set specifications for sulfur and other constituents under its reformulated gasoline (CaRFG) program in 1996, and U.S. EPA implements a parallel program at the federal level. Continued focus on gasoline formulation will assist in improving air quality along with tailpipe emission standards.
Toyota has a solid track record in the automobile industry of continuous in-use compliance. Our cars contribute to improving air quality by complying with emission requirements for the useful life of the vehicle, which for some models is up to 150,000 miles. Staff from both U.S. EPA and California ARB evaluated Toyota's conduct of these government mandated in-use testing programs, and provided both positive feedback and approval. We tested 200 vehicles in FY2010, for a total of over 1,200 vehicles since 2000, and Toyota's emission compliance rate is still a leader among major industry manufacturers. (Target 10.2)
Toyota has achieved high fuel efficiency and cleaner exhaust emissions by introducing leading-edge design and electronic control technologies. (Target 10.3) We do this in parallel with base technologies of catalytic converters and electronic fuel injection, oxygen and air/fuel sensors and dual-overhead cams to achieve cleaner vehicle emissions.
Automobile manufacturing involves a number of inputs, activities and processes to create a consumer-ready vehicle. Some of these activities and processes release pollutants to the atmosphere, many of which are regulated. One group of pollutants emitted from our plants is VOCs. Within Toyota's facilities, painting operations generate the majority of our VOC emissions.
VOCs can also be emitted from materials in the vehicle interior after manufacturing, commonly recognized as the "new car smell." Plastics, leathers, and textiles installed with glues and sealants off-gas, and this effect can be exacerbated by heat. We discuss our efforts to reduce both VOCs during manufacturing and in vehicle cabins, below.
One of our goals is to implement initiatives to track and reduce VOC emissions from our painting operations. We measure VOC emissions from vehicle painting operations in grams of VOCs emitted per square meter (g/m2) of vehicle surface area coated. Our five-year target was to achieve a corporate average of 14.0 g/m2 by FY2011, and we surpassed this target in FY2008. (Target 11.1) We continue to achieve reduced levels of VOC emissions, and in FY2010 averaged 12.4 g/m2 (please see Figure O below).
All of Toyota's North American plants with body painting operations participate in a VOC working group, led by our manufacturing headquarters in Erlanger, Kentucky. The group focuses on sharing best practices and kaizens that reduce VOC emissions. The following are examples of projects from this past year that resulted in reduced VOC emissions from vehicle painting:
- At our plant in San Antonio, Texas, several kaizens were implemented to reduce VOC emissions by almost 1.3 g/m2:
- Clear coat color blocking. Our vehicle painting process has now been reprogrammed so that the required combination of a supplier's nonsolid paint and its own clear coat are run in blocks of vehicles. This reduces the number of times that robots have to purge and clean their lines between paints from different suppliers.
- Cartridge machine solvent reduction. Team members found that they could reduce the amount of solvent the cartridge machines use to purge and clean the paint spray applicators without issue.
- Primer pre-spray reduction. Cars going through the painting process receive primers of various colors. When a robot needs to switch from one primer color to another, it still has leftover primer in its lines from the previous car that was sprayed. Instead of expelling the previous color into a waste collection system before the next vehicle comes along, that primer could be used on the next body in areas that are covered by parts, reducing the overall amount of material sprayed.
- At our plant in Georgetown, Kentucky, the paint shop team members worked to optimize the collection of purge solvent used in robot paint lines and in the paint booth to reduce VOCs. They also reduced the amount of purge solvent used by lowering the flow rate of the solvent in the robot paint lines, and the total time that the purge solvent is sprayed through the lines.
VOC performance is tracked and reported on a monthly basis by each of our plastic paint shops in North America. Currently, we do not have an overall North American VOC target for painting vehicle plastics. However, we have set a VOC target for the five plants with shops that paint exterior plastic parts such as bumpers. (Target 11.2) These plants are tracking their performance internally against these targets.
At our plant in British Columbia, Canada, our team members have conducted several innovative projects that reduce VOCs:
- Wheel edge coat paint reduction. In FY2010, we were able to reduce our paint consumption by 22 percent per wheel by removing edge coat paint from wheels that did not require it.
- Biofilter technology. Instead of installing a regenerative thermal oxidizer (RTO) to combust VOCs emitted from the painting operation, the site installed a biofilter that uses microorganisms to consume VOCs. Unlike an RTO, the biofilter does not run on fossil fuels, and has continually seen efficiency improvements since its installation. In CY2009, the biofilter destroyed over 13 tons of VOCs from the paint booths.
Reducing Cabin VOCs
Auto manufacturers in North America are working toward one global standard to test emissions of VOCs in vehicle cabins and at the component level. Currently, two voluntary standards exist: one from the Japan Automobile Manufacturers Association (JAMA), and a draft from the International Organization for Standardization (ISO). The JAMA standard was developed by modifying what are known as "sick home" indoor air quality stan dards to apply to vehicle cabin air quality. Toyota has made a voluntary commitment to meet the JAMA standard by 2011. The redesigned model year 2011 Sienna already conforms to this standard.
In North America, our research and development staff is also working on low-VOC and reduced odor technologies. A newly developed odor prediction method is the water extraction smell test. The test predicts the smell of parts in a severe vehicle cabin condition by using a high temperature. Toyota staff worked with suppliers to develop ways to reduce toluene emissions from tapes used as a secondary attachment method for several interior parts. They developed new tapes that reduce toluene emissions by more than 90 percent. Examples of these applications are ethylene propylene polymer seals used under the instrument panel and felt tape used for noise, vibration and harshness reduction. The tape is now being used in some North American models. Through these and similar efforts, Toyota is making steady progress to reduce VOC levels in vehicle cabins. (Target 9.4)