1. DIESEL EXHAUST EMISSIONS
EPA

2. EPA Criteria Pollutants
Ground Level Ozone
Nitrogen Oxides
Particulate Matter
Carbon Monoxide
Sulfur Oxides
Lead
The Clean Air Act requires EPA to set National Ambient Air Quality Standards for six common air pollutants. These commonly found air pollutants (also known as "criteria pollutants") are found all over the United States. They are particle pollution (often referred to as particulate matter), ground-level ozone, carbon monoxide, sulfur oxides, nitrogen oxides, and lead. These pollutants can harm your health and the environment, and cause property damage. Of the six pollutants, particle pollution and ground-level ozone are the most widespread health threats.

3. Ozone Formation
Ground-level or "bad" ozone is not emitted directly into the air, but is created by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOC) in the presence of sunlight. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOC.
Breathing ozone, a primary component of smog, can trigger a variety of health problems including chest pain, coughing, throat irritation, and congestion. It can worsen bronchitis, emphysema, and asthma. Ground-level ozone also can reduce lung function and inflame the linings of the lungs. Repeated exposure may permanently scar lung tissue.

4. California Nox Sources
NOx forms quickly from emissions from cars, trucks and buses, power plants, and off-road equipment. In addition to contributing to the formation of ground-level ozone, and fine particle pollution, NO2 is linked with a number of adverse effects on the respiratory system.

5. Particulate Matter
Particle pollution, also called particulate matter or PM, is a complex mixture of extremely small particles and liquid droplets in the air. When breathed in, these particles can reach the deepest regions of the lungs. Exposure to particle pollution is linked to a variety of significant health problems, ranging from aggravated asthma to premature death in people with heart and lung disease. Particle pollution also is the main cause of visibility impairment in the nation’s cities.

6. Carbon Monoxide
Carbon monoxide, or CO, is a colorless, odorless poisonous gas that is formed when carbon in fuel is not burned completely.  It is a component of motor vehicle exhaust, which contributes about 56 percent of all CO emissions nationwide.  Other non-road engines and vehicles (such as construction equipment and boats) contribute about 22 percent of all CO emissions nationwide.

7. EPA Emissions Standards
1974 – % reduction in PM and NOx emissions
1970 Congress passes the Clean Air Act - President Nixon forms the EPA –
1985 NOx and particulate standards have been tightened for on-road diesel engines. Achieved by changing injector timing and smoke control
1990 reduce the sulfur content in diesel fuel by 97 percent. This means that for the first time ever, heavy-duty trucks and buses would be able to use pollution-control devices to meet emission standards,
1994 For urban bus engines, the particulate standard was reduced to 0.07 g/bhp-hr and again in 1996 to 0.05 g/bhp-hr.
1998 The NOx standard was reduced to 4.0 g/bhp-hr for all on-road
diesel engines (bus and truck engines).
2001 – Suit by EPA against Engine Manufacturers for tamperproof violation accelerated 2004 emissions level to 2002
2007 – introduction of active PM traps
2010 – Introduction of SCR after-treatment

10. Conclusions
All Major Markets Moving to Tight PM and NOx Emission Standards for Diesel Engines
A Variety of Technologies Are Available and Emerging for PM, NOx, and Toxic HC Emission Control for Both Diesel Light-Duty and Heavy-Duty Vehicles
On-Road Diesel Technologies Will Migrate into Nonroad Diesel Applications
Retrofit NOx Technologies Expected to Expand in the Near Term to Include HC-and urea-SCR options for on-road and off-road applications

11. Conclusions
A Potential business opportunity exists in servicing, maintaining and installing after treatment systems